Categories
EEE

Overview of Energy Sector in Bangladesh

Introduction

Electricity is the most potential for foundation of economic growth of a country and constitutes one of the vital infrastructural inputs in socio-economic development .The world faces a surge in demand for electricity that is driven by such powerful forces as population growth, extensive urbanization, industrialization and the rise in the standard of living.

Bangladesh, with its 160 million people in a land mass of 147,570sq km. In 1971, just 3% of Bangladesh’s population had access to electricity .Today that number has increased to around 50% of the population –still one of the lowest in the world-but access often amounts to just a few hours each day. Bangladesh claims the lowest per-capita consumption of commercial energy in South Asia, but there is a significant gap between supply and demand. Bangladesh’s power system depends on fossil fuels supplied by both private sector and state-owned power system. After system losses, the countries per installed capacity for electricity   generation can generate 3,900-4300 Megawatts of electricity per day; however, daily demand is near   6,000 Megawatts per day. In general, rapid industrialization and urbanization has propelled the increase in demand for energy by 10% per year. What further exacerbates Bangladesh’s energy problems is the fact the country’s power generation plants are dated and may need to be shut     down sooner rather than later.

There was no institutional framework for renewable energy before 2008; therefore the renewable energy policy was adopted by the government. According to the policy an institution, Sustainable & Renewable Energy Development Authority (SREDA), was to be established as a focal point for the promotion and development of sustainable energy, comparison of renewable energy, energy efficiency and energy conservation. Establishment of SREDA is still under process. Power division is to facilitate the development of renewable energy until SREDA is formed.

While the power sector in Bangladesh has witnessed many success stories in the last couple of years, the road that lies ahead is dotted with innumerable challenges that result from the gaps that exist between what’s planned versus what the power sector has been able to deliver. There is no doubt that the demand for electricity is increasing rapidly with the improvement of living standard, increase of agricultural production, progress of industries as well as overall development of the country.

Power Generation Scenery in Bangladesh

Severe power crisis compelled the Government to enter into contractual agreements for high-cost temporary solution, such as rental power and small IPPs, on an emergency basis, much of it diesel or liquid-fuel based. This has imposed tremendous fiscal pressure. With a power sector which is almost dependent on natural-gas fired generation (89.22%), the country is confronting a simultaneous shortage of natural gas and electricity. Nearly 400-800 MW of power could not be availed from the power plants due to shortage of gas supply. Other fuels for generating low-cost, base-load energy, such as coal, or renewable source like hydropower, are not readily available and Government has no option but to go for fuel diversity option for power generation.

When the present Government assumed the charge, the power generation was 3200 – 3400 MW against national demand of 5200 MW. In the election manifesto, government had declared specific power generation commitment of 5000 MW by 2011 and 7000 MW by 2013.

Over View of Electricity Last Couple of Year

To achieve this commitment, in spite of the major deterrents energy crisis and gas supply shortage, government has taken several initiatives to generate 6000 MW by 2011, 10,000 MW by 2013 and 15,000 MW by 2016, which are far beyond the commitment in the election manifesto. 2944 MW of power (as of Jan, 2012) has already been added to the grid within three years time. The government has already developed Power system Master Plan 2010. According to the Master Plan the forecasted demand would be 19,000 MW in 2021 and 34,000 MW in 2030. To meet this demand the generation capacity should be 39,000 MW in 2030. The plan suggested going for fuel-mixed option, which should be domestic coal 30%, imported coal 20 %, natural gas (including LNG) 25%, liquid fuel 5%, nuclear, renewable energy and power import 20%. In line with the Power system Master Plan 2010, an interim generation plan up to 2016 has been prepared, which is as follows:

Table 01: Plants Commissioned During 2009-2011

Power Generation Sector

2009 (MW)

2010 (MW)

2011 (MW)

TOTAL (MW)

Public

 –

255

800

1055

Private

356

270

125

751

Q. Rental

 –

250

838

1088

Total

356

775

1763

2894

  *In 2011, 1763 MW commissioned against plan for 2194 MW

Power Generation Units (fuel Type Wise)

Table 02: Installed Capacity of BPDB Power Plants as on April 2012

Plant Type

Total Capacity (in MW)

(%) Percentage in total developed power

Gas

5086.00 MW

75.99 %

HSD

682.00MW

10.19%

HFO

335.00 MW

5.01 %

Coal

250.00MW

3.74%

Hydro

230.00 MW

3.44 %

F.Oil

110.00MW

1.64%

Total

6693.00MW

100%

Table 03: Dreaded Capacity of BPDPB Power Plants as on April 2012

Plant Type

Total Capacity (in MW)

(%) Percentage in total developed power

Gas

4651.00 MW

76.74 %

HSD

657.00MW

10.84%

HFO

248.00 MW

4.09 %

Coal

200.00MW

3.3%

Hydro

220.00 MW

3.63 %

F.Oil

85.00MW

1.4%

Total

6061.00MW

100%

 OWNER WISE DALY GENERATION REPORT

Table 04: Daily Generation of 25/04/2012

Owner Name

Derated Capacity(MW)

Day Peak(MW)

Eve. Peak(MW)

PDB

3209.00

1311.00

1516.00

SUB,PDB

223.00

51.00

104.00

EGCB

210.00

80.00

86.00

APSCL

662.00

539.00

567.00

IPP

1260.00

1021.00

1196.00

SIPP,REB

110.00

97.00

81.00

Rental(3 years)

33.00

15.00

0.00

SIPP,REB

215.00

150.00

156.00

Q.Rental 3Years

250.00

162.00

203.00

Rental 15 years

21.00

20.00

13.00

QRPP(5yars)

315.00

136.00

304.00

Others

0.00

49.00

60.00

RPP (3YEARS)

420.00

172.00

281.00

QRPP(3YEARS)

476.00

196.00

198.00

RPP(15YARS)

147.00

125.00

134.00

Total

7551.00

4124.00

4899.00

Table 05: Maximum Generation: Last Six Year

Maximum generation in 2012

6066.00MW as on 22-03-2012

Maximum generation in 2011

5174.00MW as on 23-11-2011

Maximum generation in 2010

4698.50MW as on 20-082010

Maximum generation in 2009

4296.00MW as on 18-09-2009

Maximum generation in 2008

4036.70MW as on 19-09-2008

Maximum generation in 2007

4130.00MW as on 17-09-2007

Maximum generation in history

6066.00MW as on 2908-2011

Electricity Demand and Supply

Per capita generation of electricity in Bangladesh is now about 252KWh. In view of the prevailing low consumption base in Bangladesh, a high growth rate in energy and electricity is indispensable for facilitating smooth transition from subsistence level of economy to the development threshold. The average annual growth in peak demand of the national grid over the last three decades was about 8.5%. It is believed that the growth is still suppressed by shortage of supply. Desired growth is generation is hampered, in addition to financial constraints, by inadequacy in supply of primary energy resources. The strategy adopted during the energy crisis was to reduce dependence on imported oil through its replacement by indigenous fuel. Thus almost all plants built after the energy crises were based on natural gas as fuel. Preference for this fuel is further motivated by its comparatively low tariff for power generation.

 Power Demand Forecasts (2010-2030)

The adoption scenarios of the power demand forecast in this MP are as shown in the figure below.

The figure indicates three scenarios; (i) GDP 7% scenario and (ii) GDP 6% scenario, based on energy intensity method, and (iii) government policy scenario.

 

FY

Government Policy Scenario

Comparison GDP (7%)

                  Scenario

Comparison GDP (6%)        Scenario

Peak Demand

     (MW)

Generation

   (GWH)

Peak Demand

      (MW)

Generation

     (GWH)

Peak Demand

   ( MW)

Generation

    (GWH)

2010

6454

33922

6454

33922

6454

33922

2011

6765

35557

6869

36103

6756

35510

2012

7518

39515

7329

38521

7083

37228

2013

8349

43882

7837

41191

7436

39084

2014

9268

48713

8398

44140

7819

41097

2015

10283

54047

9019

47404

8232

43267

2016

11405

59945

9705

51009

8680

45622

2017

12644

66457

10463

54994

9165

48171

2018

14014

73658

11300

59393

9689

50925

2019

15527

81610

12224

64249

10255

53900

2020

17304

90950

13244

69610

10868

57122

2021

18838

99838

14249

75517

11442

60640

2022

20443

109239

15344

81992

12056

64422

2023

21993

118485

16539

89102

12713

68490

2024

23581

128073

17840

96893

13416

72865

2025

25199

137965

19257

105432

14167

77564

2026

26838

148114

20814

114868

14979

82666

2027

28487

158462

22509

125209

15848

88156

2028

30134

168943

24353

136533

16776

94053

2029

31873

180089

26358

148928

17768

100393

2030

33708

191933

28537

162490

18828

107207

Table 06: Demand Forecast (3scenario)

Source: Power System Master Plan (PSMP) Study Team

FY- Forecast year*

INSTALLED CAPACITY

NEW GENERATION PLAN OF THE GOVERNMENT (From 2012 to2016) In MW

Power is the precondition for social and economic development. But currently consumers cannot be provided with uninterrupted and quality power supply due to inadequate generation compared to the national demand. To fulfill the commitment as declared in the Election Manifesto and to implement the Power Sector Master Plan 2010, Government has already been taken massive generation, transmission and distribution plan. The generation target up to 2016 is given below:

YEAR

2012

2013

2014

2015

2016

       TOTAL

PUBLIC

632MW

1467MW

1660MW

1410MW

750MW

5919MW

PRIVET

1354MW

1372MW

1637MW

772MW

1600MW

6735MW

IMPORT

0

500MW

0

0

0

500MW

TOTAL

1986MW

3339MW

3297MW

2182MW

2350MW

13154MW

Table 07: Power generation addition from 2009-11

     *2894 MW Power Generation addition from January 2009 to December 2011

Government Upcoming Nearest plan

Government has taken short, medium and long term plan. Under the short term plan, Quick Rental Power Plants will be installed using liquid fuels/gas and capable to produce electricity within 12-24 months. Nearly 1753 MW is planned to be generated from rental and quick rental power plants.

Under the medium term plan, initiatives have been taken to set up power plants with a total generation capacity of 7919 MW that is implementable within 3 to 5 years time. The plants are mainly coal based; some are gas and oil based. In the long term plan, some big coal fired plants will be set up, one will be in Khulna South and other will be in Chittagong, each of having the capacity of 1300 MW. Some 300-450 MW plants will be set up in Bibiana, Meghnaghat, Ashugonj, Sirangonj and in Ghorashal. If the implementation of the plan goes smoothly, it will be possible to minimize the demand-supply gap at the end of 2012.

Government has already started implementation of the plan. Total 31,355 Million-kilowatt hour (MkWh) net energy was generated during 2010-11. Public sector power plant generated 47% while private sector generated 53% of total net generation. The share of gas, hydro, coal and oil based energy generation was 82.12%, 2.78%, 2.49% and 12.61% respectively. On the other hand, in FY 2009-10, 29,247 million-kilowatt hour (MkWh) net energy was generated i.e. electricity growth rate in FY 2011 was 7.21% (In FY 2012 (Jul-Dec, 2011) is 13.2%).

Why do we select this project?

Now fuel crises are increasing day by day in worldwide and it impacts on energy sector to produce or generate electricity. Big amount of fuel from total reserved of fuel in our country is used to generate electricity.

Therefore the reserved fuel will be finish in the future. Analysis are thinking to make the strong energy sector with the rentable energy is one of the major part of the renewable energy to produce electricity and that is why we have chosen the solar energy system.

The solar system is constructed with various types of ingredients. But here the battery is the heart of the solar system. The solar energy is not used directly and it is used with the help of the battery because we get very low D.C voltage from the solar panel. Therefore we need to use the battery to store this low D.C voltage which is supplied from the solar panel. In a solar system, the 50% cost is expense for the battery from its total cost. Since the battery is a major part of the solar system and it is charged perfectly by a controller circuit. If the battery is not charged perfectly then the charge capacity will be decreasing in a very short time and it also can be damaged for the overcharging.

We have chosen the battery charge controller system by considering above reason.

Energy Sector

Categories
EEE

Data Security Services for Smartphone Users

Introduction

Today’s world is becoming more and more integrated, interconnected and intelligent. Mobil devices are playing an ever-increasing role in changing the way and concept of information communication system. Mobile device technology is now blessed with smartphones and tablets. Not only the busy corporate world, but also the regular users of every age are getting involved to them. Employees of various organizations are now bringing their own devices to the workplaces and asking the organization to support them. These new devices offer improved hardware performance, more robust platform feature set and increased communication bandwidth. As a result these increased accesses to the organization’s enterprise system can also bring an increased security risk to the organization. It’s no exaggeration to say that smartphones have become ubiquitous in government and in the population at large, and it’s no wonder. These devices allow users to remain productive, even when walking between destinations, stuck on public transit, or during downtime in meetings.

Modern Generation Smartphones

Modern Generation smartphones generally use ARM microprocessor with clock rates over 1 GB, some models have already arrived in market with dual or quad-core CPUs and even higher clock rates. They have gigabytes of storage and reasonably fast networks. In these respects,current smartphones are faster and better-provisioned than desktop computers from a decade ago. This raises an interesting opportunity because smartphones have more than adequate resources to leverage decades of research into secure operating systems. Smartphones from most vendors can or will soon run full-blown Unix-style operating systems. Smartphones from most vendors can or will soon run full-blown Unix-style operating system kernels. This means that security features ranging from virtualization and secure booting to information flow control and multi-level security can potentially be applied to creating high-assurance software within smartphones.

 Data Security Trends

Many stakes of our socio-economical life such as government, military, private and public sectors, IT departments etc are locking personnel out of social sites rather pushing these users to do these activities on personal smartphones. As a result these personnel are using their smart devices to visit social sites. This is eventually increasing more and more uses of smart devices. Application markets are rapidly increasing. There are millions of applications to download. Smartphone users may take the advantage of having experienced with these applications and utilities. All these activities does not keep users from storing sensitive and private information on their deices.

 Data Security on Smartphone

Most of the regular smartphone users have some information stored in their mobile phone that they consider sensitive and secret. An average user today has about 25 passwords to manage and if they find difficulties to memorize them, they tend to use weak or easy-to-memorize passwords. Even after choosing easy passwords they usually forget some of them after sometime anyway. These information can be categorized as mobile data.

 Types of Mobile Data

Primarily there are three types of mobile data that we can consider on security threats.

  • Voice data
  • Data in motion (i.e. sending data over an unsecured wireless network)
  • Data at rest (i.e. phonebook, message, music list, game score etc)

Data Encryption Service

A single user can be the owner of multiple devices. For example, let us consider a student who is studying Computer Science and Engineering. S/he needs a computer for working on various types of softwares/IDEs; therefore s/he owns a desktop computer. While on having tours s/he wants to read books and listening to music, so s/he bought a tablet. S/he also needs so make phone calls while having tour, so s/he also got a smartphone. S/he uses each of these devices to store various kinds of data and obviously wants to keep some of data encrypted or protected. What our sample user needs is a possibility for storing sensitive data in secured (encrypted) way and to be able to synchronize those data over the network. Our goal is to provide this possibility through an encryption service.

Feasibility Study

An important outcome of the preliminary investigation is the determination that the system requested is feasible. Feasibility study is carried out to select the best system that meats the performance requirements.

 Technical Feasibility

The technical feasibility issue usually occurred on the basis of system requirements. The implementation of our thesis work requires Android which is widely available in a variety of platforms. So in a short this we consider that the work will be carried out satisfying the technical feasibility.

Operational Feasibility

The operational feasibility measures how well a proposed system solves the problem. The outcome of our thesis work offers a greater level of user friendly behaviors. As the volume of the work is large, the operational feasibility depends on the success of each module.

Economical Feasibility

Economic feasibility refers to the cost/benefit analysis of a project. To conduct each and every module of our thesis work is economically feasible. Both the development cost and operating cost is tolerable.

DATA SECURITY USING CRYPTOGRAPHY

Data Security Using Cryptography

 In this chapter we will discuss about the uses of cryptographic algorithms and functions. Cryptography is typically applied when trying to ensure data confidentiality, to authenticate people or devices, or to verify data integrity in risky environments.

 AES Cypher

AES is a specification for the encryption of electronic data that was established and announced by the U.S. National Institute of Standards and Technology (NIST) in 2001. It was developed by two cryptographers, Joan Daemen and Vincent Rijmen. AES is based on a design principle known as a substitution-permutation network, and is fast in both software and hardware. AES does not use a Feistel network like DES. AES has a fixed block size of 128 bits and a key size of either 128, 192, or 256 bits. AES operates on a 4 x 4 column-major order matrix of bytes, termed the state (versions of Rijndael with a larger block size have additional columns in the state). The AES cipher is specified as a number of repetitions of transformation rounds that convert the input plaintext into the final output of ciphertext. Each round consists of several processing steps, including one that depends on the encryption key. A set of reverse rounds are applied to transform ciphertext back into the original plaintext using the same encryption key. The exact description of the cipher can be found in.

 Cryptographic Hash Function

A cryptographic hash function is a hash function that takes an arbitrary block of data (message) and returns a fixed-size bit string which is called cryptographic hash value. If any changes are made on data the hash value also changes. The ideal cryptographic hash function implements seudorandom one-way function and has the following four main properties:

  • Must be easy to compute the hash value for a given message or data.
  • It is infeasible to generate a message that has a given hash.
  • It is infeasible to modify a message without changing the hash.
  • It is infeasible to find two different messages with the same hash.

The hash functions are useful as they used in various cryptographic protocols and systems. In our thesis work we will use hash function as a tool to improve the properties of random number generation

 Key Derivation Functions

A key derivation function (KDF) derives one or more secret keys from a secret value (master key, password, passphrase, other data) using a pseudo-random function. It is very important to know that the strength (resilience against adversary trying to get the secret value) of the KDF depends always on the entropy of the secret value and the difficulty to calculate the function, as adversary can guess the secret value and calculate the derived key.

Cryptography Implementation

To implement the cryptographic functions we decided to use the Open Source Toolkit for SSL/TLS – OpenSSL library. Picking this well-known implementation has several reasons. OpenSSL library is written in the C language which is well suited for the performance of cryptographic functions. OpenSSL is compliant with the cryptographic standard FIPS 140-2 which ensures the quality of the code. OpenSSL contains all the cryptographic functions we will need for our service’s implementation.

SYSTEM ANALYSIS AND DESIGN

 Analysis and Design

In this chapter we will discuss about the analysis and design phase of our thesis work. We will first describe the functional requirements and show all the related use cases. Then in the design phase we will demonstrate the components that are related to those functions.

The analysis phase works on the information that are gathered, its builds the logical model of the application. The development of a computer based information system includes a system analysis phase which produces or enhances the data model which itself is a precursor for creating or enhancing the system.

The design phase is the area of problem solving and planning for the system for carrying out the result successfully. The implementation of the designed algorithms along with low-level components. An important topic of software design is complexity management. In practical, software specifications tend to be fluid and change rapidly while the design process is still going on.

 The Functional Requirements 

It is very important to know the functionality of each and every module of a system from start to end. Functional requirements synthesize the analysis, documentation, validation and managing of a software system. The following are the important parameters directly related to the result of the analysis on our research. s

Storing the Secret Data

The client side application needs to be able to store the secret information in an encrypted way. The user can read, manipulate, and remove the information from the storage in any time. These actions can be carried out only if the user is authenticated, that is the service is unlocked.

 Data Storage Safety

The storage repository must be password protected. Here we can define the situation in two stages. After authentication that is, after entering the password the service is said to be ‘Unlocked’. It can be remain unlocked for specific a period of time, after that time it goes to the stage of ‘Locked’. Note that, no operations are allowed when the service is locked.

 Synchronization

As the secret data sharing is taking place among various Android devices owned by a single user, the service must provide a synchronization function.

 The Use Case Diagram Analysis

This section we will describe the use case diagram. Use case diagram can be used to describe the functionality of a system in a horizontal way. In our research we can divide the use cases into two groups depending on the actor’s interaction to the service. The use case diagram can be used to describe the functionality of a system in a horizontal way. The use case diagram is considered as the blue print for a system. Depending on the variation of the actor and module use cases can be divided into many groups. According to that point we can define two major sections of use cases in our research.

 The Application’s Use Cases

In this section we will discuss how the application, that is, the client application which is stored as an app in android OS environment can interact. What are the basic functions that are being done by the application itself will be shown through the diagram. Note that, the application itself will act as an actor in this section.

Checking the Service State

To initiate the client application to work, first of all a checking is needed. The application must check that the service is currently unlocked or not. The application sends a request to the service, and eventually the service replies to it. This checking portion is needed for the application to work with the next states. If the reply is a true, only then the application can work on the next steps. This activity has a sub-task, that is, entering the password. We are defining this as a sub-task, because the initialization process can be done if the encryption service is unlocked.

Storing Information

Information storing is done by an encryption key. The application sends the message along with the key. The service then processes the message and encrypts the information and stores the information under the key. Now there exits an important checking. If the provided key already exists, then the service replaces the newly arrived information with the older one. If not then the service makes a new entry and stores the information.

 Manipulating Information

The manipulation of the information mainly includes ‘Reading’ and ‘Deletion’ of the information. For reading, the application asks the service to read the information, the service then decrypts the data and then returns the result. For deletion, the application the application asks the service to delete the data; service then deletes the encrypted data and marks this information as removed, that is not readable anymore.

 Uploading Data

When the application asks the service to upload the data, the service uploads all the changed information or new entry to the server after it connects to it.

Downloading Data

 Same as the previous section, the application sends a message to the encryption service to ask for downloading the data. The service then connects to the sever and downloads the available updates of the information.

 The User’s Use Cases

The person who is handling the client application on android OS environment is considered the actor in this section of use cases. We can also define this actor as the user of the system.

 Initializing the Service

 After successfully installing the android client application package it is now ready to use. The user initializes he service by invoking it. The service becomes ready to use. The user settings along with the password are both set to their default values.

 User Setting Management

Having successfully initializing the service the user may want to change the settings such as password setting. To do so, the user finds the preference settings and then provokes the service for password setting. The service then prompts the user to put the old password then ask the user to put the new password again ask the user to retype it. If the process is successful, then the new password is set.

Synchronization Setting Management

There are two synchronization states, they are, uploading data and downloading data. After initialization, the user may found the synchronization setting in preference section of the client service. There the user can alter the synchronization service (uploading / downloading data) according to the user’s own need.

Finishing Service

In preference section the user can also find the option for termination or finishing the service. If the user chooses to terminate the client service, then the encryption service switches itself to a state which is no longer usable by the client application. This can be considered the finishing or destroying of the service.

 Components Analysis

We can describe our implementation as a collection of components too. These components will work together to cover up all the necessary functionalities to successfully complete the service. The following diagram shows the components and their responsibilities to each other and android OS also.

As described in the above diagram the components can be divided into two major categories, they are:

  • Server side application components
  • Client side application

 Server Side Application Components

The server side component contains some other services. There must an encryption library for transforming the client’s secret data or information. In additional a mailing library will be needed to support the synchronization. To keep track of every secret information we will need SQLite database.

 Client Side Application Components

To support and communicate every client application will an android application. Secret data information from client’s will be outputted into file system, so there will be need for access to the filesystem too. The most important point here is that any application will be service’s client application. By using the right set of information the user of the phone does no longer have to worry about the data insecurity.

IMPLEMENTATION

In this chapter we will discuss how our services can be implemented. We will start our discussion on android ‘Activities’ and ‘Services’. We will also take a look on the background services and all other possibilities related to the implementation.

Android Activity and Service

We can define application components as the essential building blocks for our service. All components are not the usual entry point for the user and some can be dependable on each other, but the important fact is each one exists as its own entity and plays a specific role. There are four different types of application components: Activities, Services, Content providers and Broadcast Receivers. Two of the four were used to develop the encryption service: Activities and a Service. We will now shortly describe each of these two components.

An activity simply represents a single screen with a user interface. Although all the activities work together to form a complete application solution, each one can be independent from each other. An important thing is different application or application part can invoke any one of these activities. In android an activity is implemented as a subclass of Activity class.

A service is a component that runs in the background to perform long-running operations or to perform work for remote processes. A service does not need a user interface. For example, a service might download a file from internet while the user is in a different application.

Using Intents for Starting Activities and Services 

As there is no main() function in android so android applications do not have a single entry level.  Android gives us a more powerful feature that is any application can invoke another application’s components. There are several permissions that restricts to access one application’s components to another. To activate a component every application needs to pass messages to the system, these messages are called intents. Intents are basically objects which specify the URI of the data to at on. For example, a URI of an image to show by an image viewer application, or a URI of web content sent to a web browser. There are two methods o activate an intent. They are:

  • startActivity, which is used when you don’t want a result to be returned. This is a one way flow of activity invocation.
  • startActivityForResult, this is used when you want an activity to return a result. This a both way communication between activities as the returned data can be manipulated bye the caller activity.

Filtering the Services

To make the services available to the application it is necessary to declare the services first. To support this, a listing of the intents can be done. In android the list of all activities which can be invoked by the intents are listen in android’s ‘AndroidManifest.xml’ file. The OS reads it and prepare classes that would be used as activity. Also the manifest decides which class can be called as the launcher activity.

Service Initialization

Initializing an application means getting it into a default state and let the user to run and invoke. For additional default state android offers ‘SharedPreferences’ to store application values. For example a game application can store high-score in sharedpreferences. For our service a default password is set in initial state. Finally a default name value is set.

Building Encryption Operation

We will go for the AES encryption tool that can be used on android platform. Though there exists several C / C++ AES library, we will go for Java’s built in ‘Cypher’, ‘KeyGenerator’ etc to provide AES and its property. In addition to our implementation we can also have a look at android’s powerful NDK. The Android NDK is a companion tool to the Android SDK that lets us build performance-critical portions of our apps in native code. It provides headers and libraries that allow us to work with the Android OS. One can handle user input, use hardware sensors, access application resources, and more, while programming in C or C++. The fundamental Android application model does not change, the application is still built in an .apk file and the application still runs inside of a virtual machine on the device.

The Functionalities

In our analysis part of our thesis we described about the basic functionalities that our service must meet. The following section describes the approaches and behaviors of these functions.

 Storing Data

When the user asks the service to store secret data a random salt bite is generated in cryptographic stage. The same bytes can be used to read when decrypting the encrypted data. The java.security.* packages can be used to perform this operation. The bytes of the secret information is then sent to OpenSSL for encryption. At last the changes are arranged in SQLite database. There can be two situation:

  1. The secret information is new, so a new row is added to the table.
  2. The secret information is not new. In this case the respective table row is updated.

Reading Data

When the user asks the service to read a data that was previously stored, the controller first locates the file with the secret key. Then the first eight bites are read which we call the salt bites. The remaining bites are decrypted and returned back to the calling user.

Deleting Data

When the user asked the service to delete the secret data, the controller finds the encrypted file and deletes it from the filesystem. Their raises two conditions with the deletion situation.

  1. The secret information has never been uploaded – the uploaded _eld is false, thus the deletion does not have to be uploaded.
  2. The secret information has been uploaded before – the uploaded _eld is true, thus the deletion need to be uploaded the next time the upload operation is invoked by the user.

 Destroying the Service

User can either destroy the application or uninstall the whole application from the system. In general an exit button exist which contains a click listener, in that click listener call back the application destroy function that is finish() is called. The calling of  finish method invokes the android onDestroy.

 Invoking the Services

With the help of remote procedure calls (RPCs) android offers interprocess communication which remotely executes an activity of other application and brings back the result to the caller. This discussion is necessary as our service runs in background and listens for any request that comes from client application. The service and application can exchange messages as soon as they get bound. RPCs are useful as they provide synchronous communication.

The Basic of Upload and Download Operations

For the upload-download operation we need JavaMail library. Eventually these operations will need another uses permission in android’s manifest and the permission is INTERNET. All IMAP and SMTP preferences have to fill correctly in order to connect to the mail servers successfully. If any of the previously mentioned requirements are not fulfilled, the user is informed about the problem and a called operation does not carry on.

Service Preferences

There are several preferences that we should provide for the end user so that the user can use the total application in a correct way. The following are the preferences that can be compatible to provide to the user.

  • Password – Our service start with a  default password which can changed or removed by the user. All the flow of secret information is done using this password, so it is logically important for the user to provide a strong password.
  • Password validity – There can be a time period after which the entered password is expired. The user then have to put a new password along with the old one. The new password replaces the older one.

 Error Reporting

In addition to the above discussion we should provide the user with an error reporting system. Testing an application thoroughly prior to releasing is of course a very important part of the development process, but errors usually do occur anyways. Different errors may show up when using various devices or operating system versions. The total number of different Android device models has quickly gone from tens to hundreds and it has become impossible for a developer to have them all in order to test their application on each one of them. Getting error reports from those users to developers is the only way how issues can be taken care of.

SECURITY SOLUTIONS AND COMPARISON

 Security Solutions and Comparison

 In this chapter we will discuss about the existing security solutions for mobile devices and some comparison between them and our application service.

Existing Available Solutions

There are very few numbers of open source and commercial solutions available in marketplaces. As the mobile devices and their market places are still in positive growth, its is very hard to find a security solution that we proposed in our thesis work. Among the most famous ones is an open-source solution called TrueCrypt, which offers automatic, transparent, real-time (on-the-fly) partition or drive encryption.

Comparison with Our Own Service

In our provided service data is always secure while the service is unlocked. Data protection is occurs in same way when the phone remains switch off or not. Moreover it will cause no hamper to the local file system (sd card occasionally). Finally as we are using an encryption system, data and user request is remains in safety. Everything is done automatically so the user illogical input exception reduces.

Modern Cloud Storage Concept

In modern storage concept storing data in clod storage is getting popularity day by day. Many of them do not provide client-side encryption though. Among them DropBox or Box, Google Drive are most popular.  Another concept is very useful for the developer with large scale of developing team who are diversified worldwide. They are usually called versioning system. In recent years Github, BitBucket etc are getting popular. They provide Git repository to connect, push, pull, merge, delete etc on the project files. Also provides history of committing each time which helps to find out the changes that are made.

Comparison with Our Service

As in our service we are providing data flow with update, new entry insertion and deletion we can compare these actions to the repository system that we described earlier. A disadvantage or limitation of the service is that if the user need more that one type of information, more that one application is required.

RESULTS AND CONCLUSION

Results and Conclusion

In this chapter we are going to conclude or summarize our achievements and proposing some enhancements for further interest.

 Achieved Results

This project was initiated for a couple main reasons. The first one is that we decided to improve personal data security on a user’s device. The other main reason was that we as developers wanted to gain new programming experience. The objective was developing a service that can be implemented on very new technology like android embedded system as android platform is expanding and becoming a powerful and popular working field for the developers. Also the objective of this thesis work was to design a service that can run in background that is capable of connecting to other components of one or more activities. Before working on this topic we have no vast knowledge on android so that we could design such a large and robust application concept. During the implementation we had to learn about Android components (activities, services), delivering intents etc.

Considering the above gaining we can say that the achieved results of our thesis work gains success in various dimensions. Working of the thesis surely enriched us of some Android development skills and the expectations were met. We hope this work with all its concepts, ideas and design will be helpful to the others.

Possible Enhancements

The following are the list of possible enhancements that can be implemented in future if they are technically feasible.

  • Support for different platforms, for example Windows, Mac, Linux etc.
  • Data sharing among different users. If the service can be made available for different platforms, there will be different users with different OS. So synchronizations must be done.
  • Various authentication methods can be applied such as biometrics authentication.
Categories
EEE

Solar Energy

Introduction

 The interest in renewable energy has been revived over last few year, especially after global awareness regarding the ill effects of fossil fuel burning. Energy is the source of growth and the mover for economic and social development of a nation and its people. No matter how we cry about development or poverty alleviation it is not going to come until lights are provided to our people for seeing, reading and working.

Natural resources or energy sources such as; fossil fuels, oil natural gas, etc. are completely used or economically depleted. Because we are rapidly exhausting, our non-renewable resources, degrading the potentially renewable resources and even threatening the perpetual resources. It demands immediate attention especially in the third world countries, where only scarce resources are available for an enormous size of population. The civilization is dependent on electric power. There is a relationship between GDP growth rate and electricity growth rate in a country.

Clearly, the present gas production capacity in Bangladesh can’t support both domestic gas needs,  as well as wider electricity generation for the country . On September 15th 2009, the Power Division of the Ministry of Power, Energy  and Mineral Resources of Bangladesh pushed for urgent action to be taken to improve the country’s energy outlook. The Power Division made recommendation such as ceasing gas supply to gas-fired power plants after 2012 to conserve gas reserves for domestic use.

The Government of Bangladesh is actively engaged in energy crisis management. The National Energy Policy has the explicit goal of supplying the whole country with electricity by 2020. Since 1996, the government has allowed private, independent power producer to enter the Bangladeshi market. It is already importing 100 Megawatts of power from India and has negotiated with private companies renting plants to buy power at higher rates.

It is impossible to conceive development of civilization without “Energy”.Densely populated country like Bangladesh can only sustain and progress if only latest energy technologies can be used efficiently. Government of Bangladesh is working towards achieving “Power i.e. Electricity for All” by the year 2020.Bangladesh is one of the most severely affected counties of the World due to climate change and global warming effects.

   What Is Solar Energy?

Solar energy is energy that comes from the sun. Every day the sun radiates, or sends out, an enormous amount of energy. The sun radiates more energy in one second than people have used since the beginning of time!

Where does all this energy come from? It comes from within the sun itself. Like other stars, the sun is a big gas ball made up mostly of hydrogen and helium. The sun generates energy in its core in a process called nuclear fusion. During nuclear fusion, the sun’s extremely high pressure and hot temperature cause hydrogen atoms to come apart and their nuclei (the central cores of the atoms) to fuse or combine. Four hydrogen nuclei fuse to become one helium atom. But the helium atom weighs less than the four nuclei that combined to form it. Some matter is lost during nuclear fusion. The lost matter is emitted into space as radiant energy.

It takes millions of years for the energy in the sun’s core to make its way to the solar surface, and then just a little over eight minutes to travel the 93 million miles to earth. The solar energy travels to the earth at a speed of 186,000 miles per second, the speed of light. Only a small portion of the energy radiated by the sun into space strikes the earth, one part in two billion. Yet this amount of energy is enormous. Every day enough energy strikes the United States to supply the nation’s energy needs for one and a half years!

Where does all this energy go? About 15 percent of the sun’s energy that hits the earth is reflected back into space. Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produce’s rain-fall. Solar energy also is absorbed by plants, the land, and the oceans. The rest could be used to supply our energy needs.

History of Solar Energy

People have harnessed solar energy for centuries. As early as the 7th century B.C., people used simple magnifying glasses to concentrate the light of the sun into beams so hot they would cause wood to catch fire. Over 100 years ago in France, a scientist used heat from a solar collector to make steam to drive a steam engine.

In the beginning of this century, scientists and engineers began researching ways to use solar energy in earnest. One important development was a remarkably efficient solar boiler invented by Charles Greeley Abbott, an American astrophysicist, in 1936.

The solar water heater gained popularity at this time in Florida, California, and the Southwest. The industry started in the early 1920s and was in full swing just before World War 11. This growth lasted until the mid- 1950s when low-cost natural gas became the primary fuel for heating American homes. The public and world governments remained largely indifferent to the possibilities of solar energy until the oil shortages of the 1970s. Today people use solar energy to heat buildings and water and to generate electricity.

Utilization of solar Energy

Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available renewable energy on earth. Only a minuscule fraction of the available solar energy is used.

Solar powered electrical generation relies on heat engines and photovoltaic. Solar energy’s uses are limited only by human ingenuity. A partial list of solar applications includes space heating and cooling through solar architecture, potable water via distillation and disinfection, day lighting, solar hot water, solar cooking, and high temperature process heat for industrial purposes. To harvest the solar energy, the most common way is to use solar panels.

Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.

There are main two ways we can produce electricity from the sun:

Photovoltaic Electricity – This method uses photovoltaic cells that absorb the direct sunlight just like the solar cells you see on some calculators.

Solar Thermal Electricity – This also uses a solar collector: it has a mirrored surface that reflects the sunlight onto a receiver that heats up a liquid. This heated liquid is used to make steam that produces electricity.

Solar System Descriptions

In today’s climate of growing energy needs and increasing environmental concern, alternatives to the use of non-renewable and polluting fossil fuels have to be investigated. One such alternative is solar energy.

Solar energy is quite simply the energy produced directly by the sun and collected elsewhere, normally the Earth. The sun creates its energy through a thermonuclear process that converts about 650,000,0001 tons of hydrogen to helium every second. The process creates heat and electromagnetic radiation. The heat remains in the sun and is instrumental in maintaining the thermonuclear reaction. The electromagnetic radiation (including visible light, infra-red light, and ultra-violet radiation) streams out into space in all directions.

Only a very small fraction of the total radiation produced reaches the Earth. The radiation that does reach the Earth is the indirect source of nearly every type of energy used today. The exceptions are geothermal energy, and nuclear fission and fusion. Even fossil fuels owe their origins to the sun; they were once living plants and animals whose life was dependent upon the sun.

Much of the world’s required energy can be supplied directly by solar power. More still can be provided indirectly. The practicality of doing so will be examined, as well as the benefits and drawbacks. In addition, the uses solar energy is currently applied to will be noted.

Due to the nature of solar energy, two components are required to have a functional solar energy generator. These two components are a collector and a storage unit. The collector simply collects the radiation that falls on it and converts a fraction of it to other forms of energy (either electricity and heat or heat alone). The storage unit is required because of the non-constant nature of solar energy; at certain times only a very small amount of radiation will be received. At night or during heavy cloud cover, for example, the amount of energy produced by the collector will be quite small. The storage unit can hold the excess energy produced during the periods of maximum productivity, and release it when the productivity drops. In practice, a backup power supply is usually added, too, for the situations when the amount of energy required is greater than both what is being produced and what is stored in the container.

Methods of collecting and storing solar energy vary depending on the uses planned for the solar generator. In general, there are three types of collectors and many forms of storage units.

The three types of collectors are flat-plate collectors, focusing collectors, and passive collectors.

Flat-plate collectors are the more commonly used type of collector today. They are arrays of solar panels arranged in a simple plane. They can be of nearly any size, and have an output that is directly related to a few variables including size, facing, and cleanliness. These variables all affect the amount of radiation that falls on the collector. Often these collector panels have automated machinery that keeps them facing the sun. The additional energy they take in due to the correction of facing more than compensates for the energy needed to drive the extra machinery.

Focusing collectors are essentially flat-plane collectors with optical devices arranged to maximize the radiation falling on the focus of the collector. These are currently used only in a few scattered areas. Solar furnaces are examples of this type of collector. Although they can produce far greater amounts of energy at a single point than the flat-plane collectors can, they lose some of the radiation that the flat-plane panels do not. Radiation reflected off the ground will be used by flat-plane panels but usually will be ignored by focusing collectors (in snow covered regions, this reflected radiation can be significant). One other problem with focusing collectors in general is due to temperature. The fragile silicon components that absorb the incoming radiation lose efficiency at high temperatures, and if they get too hot they can even be permanently damaged. The focusing collectors by their very nature can create much higher temperatures and need more safeguards to protect their silicon components.

Passive collectors are completely different from the other two types of collectors. The passive collectors absorb radiation and convert it to heat naturally, without being designed and built to do so. All objects have this property to some extent, but only some objects (like walls) will be able to produce enough heat to make it worthwhile. Often their natural ability to convert radiation to heat is enhanced in some way or another (by being painted black, for example) and a system for transferring the heat to a different location is generally added.

 People use energy for many things, but a few general tasks consume most of the energy. These tasks include transportation, heating, cooling, and the generation of electricity. Solar energy can be applied to all four of these tasks with different levels of success.

Heating is the business for which solar energy is best suited. Solar heating requires almost no energy transformation, so it has a very high efficiency. Heat energy can be stored in a liquid, such as water, or in a packed bed. A packed bed is a container filled with small objects that can hold heat (such as stones) with air space between them. Heat energy is also often stored in phase-change or heat-of-fusion units. These devices will utilize a chemical that changes phase from solid to liquid at a temperature that can be produced by the solar collector. The energy of the collector is used to change the chemical to its liquid phase, and is as a result stored in the chemical itself. It can be tapped later by allowing the chemical to revert to its solid form. Solar energy is frequently used in residential homes to heat water. This is an easy application, as the desired end result (hot water) is the storage facility. A hot water tank is filled with hot water during the day, and drained as needed. This application is a very simple adjustment from the normal fossil fuel water heaters.

Swimming pools are often heated by solar power. Sometimes the pool itself functions as the storage unit, and sometimes a packed bed is added to store the heat. Whether or not a packed bed is used, some method of keeping the pool’s heat for longer than normal periods (like a cover) is generally employed to help keep the water at a warm temperature when it is not in use.

Solar energy is often used to directly heat a house or building. Heating a building requires much more energy than heating a building’s water, so much larger panels are necessary. Generally a building that is heated by solar power will have its water heated by solar power as well. The type of storage facility most often used for such large solar heaters is the heat-of-fusion storage unit, but other kinds (such as the packed bed or hot water tank) can be used as well. This application of solar power is less common than the two mentioned above, because of the cost of the large panels and storage system required to make it work. Often if an entire building is heated by solar power, passive collectors are used in addition to one of the other two types. Passive collectors will generally be an integral part of the building itself, so buildings taking advantage of passive collectors must be created with solar heating in mind.

These passive collectors can take a few different forms. The most basic type is the incidental heat trap. The idea behind the heat trap is fairly simple. Allow the maximum amount of light possible inside through a window (The window should be facing towards the equator for this to be achieved) and allow it to fall on a floor made of stone or another heat holding material. During the day, the area will stay cool as the floor absorbs most of the heat, and at night, the area will stay warm as the stone re-emits the heat it absorbed during the day. Another major form of passive collector is thermos phonin walls and/or roof. With this passive collector, the heat normally absorbed and wasted in the walls and roof is re-routed into the area that needs to be heated.

The last major form of passive collector is the solar pond. This is very similar to the solar heated pool described above, but the emphasis is different. With swimming pools, the desired result is a warm pool. With the solar pond, the whole purpose of the pond is to serve as an energy regulator for a building. The pond is placed either adjacent to or on the building, and it will absorb solar energy and convert it to heat during the day. This heat can be taken into the building, or if the building has more than enough heat already, heat can be dumped from the building into the pond.

Solar energy can be used for other things besides heating. It may seem strange, but one of the most common uses of solar energy today is cooling. Solar cooling is far more expensive than solar heating, so it is almost never seen in private homes. Solar energy is used to cool things by phase changing a liquid to gas through heat, and then forcing the gas into a lower pressure chamber. The temperature of a gas is related to the pressure containing it, and all other things being held equal, the same gas under a lower pressure will have a lower temperature. This cool gas will be used to absorb heat from the area of interest and then be forced into a region of higher pressure where the excess heat will be lost to the outside world. The net effect is that of a pump moving heat from one area into another, and the first is accordingly cooled.

Besides being used for heating and cooling, solar energy can be directly converted to electricity. Most of our tools are designed to be driven by electricity, so if you can create electricity through solar power, you can run almost anything with solar power. The solar collectors that convert radiation into electricity can be either flat-plane collectors or focusing collectors, and the silicon components of these collectors are photovoltaic cells.

Photovoltaic cells, by their very nature, convert radiation to electricity. This phenomenon has been known for well over half a century, but until recently the amounts of electricity generated were good for little more than measuring radiation intensity. Most of the photovoltaic cells on the market today operate at an efficiency of less than 15%; that is, of all the radiation that falls upon them, less than 15% of it is converted to electricity. The maximum theoretical efficiency for a photovoltaic cell is only 32.3%, but at this efficiency, solar electricity is very economical. Most of our other forms of electricity generation are at a lower efficiency than this.

Unfortunately, reality still lags behind theory and a 15% efficiency is not usually considered economical by most power companies, even if it is fine for toys and pocket calculators. Hope for bulk solar electricity should not be abandoned, however, for recent scientific advances have created a solar cell with an efficiency of 28.2% efficiency in the laboratory. This type of cell has yet to be field-tested. If it maintains its efficiency in the uncontrolled environment of the outside world, and if it does not have a tendency to break down, it will be economical for power companies to build solar power facilities after all.

Of the main types of energy usage, the least suited to solar power is transportation. While large, relatively slow vehicles like ships could power themselves with large onboard solar panels, small constantly turning vehicles like cars could not. The only possible way a car could be completely solar powered would be through the use of battery that was charged by solar power at some stationary point and then later loaded into the car. Electric cars that are partially powered by solar energy are available now, but it is unlikely that solar power will provide the world’s transportation costs in the near future.

Solar power has two big advantages over fossil fuels. The first is in the fact that it is renewable; it is never going to run out. The second is its effect on the environment.

While the burning of fossil fuels introduces many harmful pollutants into the atmosphere and contributes to environmental problems like global warming and acid rain, solar energy is completely non-polluting. While many acres of land must be destroyed to feed a fossil fuel energy plant its required fuel, the only land that must be destroyed for a solar energy plant is the land that it stands on. Indeed, if a solar energy systems were incorporated into every business and dwelling, no land would have to be destroyed in the name of energy. This ability to decentralize solar energy is something that fossil fuel burning cannot match.

As the primary element of construction of solar panels, silicon, is the second most common element on the planet, there is very little environmental disturbance caused by the creation of solar panels. In fact, solar energy only causes environmental disruption if it is centralized and produced on a gigantic scale. Solar power certainly can be produced on a gigantic scale, too. Among the renewable resources, only in solar power do we find the potential for an energy source capable of supplying more energy than is used.

Suppose that of the 4.5×1017 kWh per annum that is used by the earth to evaporate water from the oceans we were to acquire just 0.1% or 4.5×1014 kWh per annum. Dividing by the hours in the year gives a continuous yield of 2.90×1010 kW. This would supply 2.4 kW to 12.1 billion people.

This translates to roughly the amount of energy used today by the average American available to over twelve billion people. Since this is greater than the estimated carrying capacity of the Earth, this would be enough energy to supply the entire planet regardless of the population.

Unfortunately, at this scale, the production of solar energy would have some unpredictable negative environmental effects. If all the solar collectors were placed in one or just a few areas, they would probably have large effects on the local environment, and possibly have large effects on the world environment. Everything from changes in local rain conditions to another Ice Age has been predicted as a result of producing solar energy on this scale. The problem lies in the change of temperature and humidity near a solar panel; if the energy producing panels are kept non-centralized, they should not create the same local, mass temperature change that could have such bad effects on the environment.

Of all the energy sources available, solar has perhaps the most promise. Numerically, it is capable of producing the raw power required to satisfy the entire planet’s energy needs. Environmentally, it is one of the least destructive of all the sources of energy. Practically, it can be adjusted to power nearly everything except transportation with very little adjustment, and even transportation with some modest modifications to the current general system of travel. Clearly, solar energy is a resource of the future.

Advantage of Solar Energy:

  1. Technology is easy
  2. Affordable cost
  3. Within the ability of poor’s
  4. Basically no maintenance cost
  5. Only source of energy is sunshine
  6. Energy source is cost free
  7. Environmental Pollution is less
  8. No emission
  9. Very few materials are required

Solar energy

Categories
EEE

Battery Charge Controller for Solar System

Introduction

Electricity is the most potential for foundation of economic growth of a country and constitutes one of the vital infrastructural inputs in socio-economic development .The world faces a surge in demand for electricity that is driven by such powerful forces as population growth, extensive urbanization, industrialization and the rise in the standard of living.

Bangladesh, with its 160 million people in a land mass of 147,570sq km. In 1971, just 3% of Bangladesh’s population had access to electricity .Today that number has increased to around 50% of the population –still one of the lowest in the world-but access often amounts to just a few hours each day. Bangladesh claims the lowest per-capita consumption of commercial energy in South Asia, but there is a significant gap between supply and demand. Bangladesh’s power system depends on fossil fuels supplied by both private sector and state-owned power system. After system losses, the countries per installed capacity for electricity   generation can generate 3,900-4300 Megawatts of electricity per day; however, daily demand is near   6,000 Megawatts per day. In general, rapid industrialization and urbanization has propelled the increase in demand for energy by 10% per year. What further exacerbates Bangladesh’s energy problems is the fact the country’s power generation plants are dated and may need to be shut     down sooner rather than later.

There was no institutional framework for renewable energy before 2008; therefore the renewable energy policy was adopted by the government. According to the policy an institution, Sustainable & Renewable Energy Development Authority (SREDA), was to be established as a focal point for the promotion and development of sustainable energy, comparison of renewable energy, energy efficiency and energy conservation. Establishment of SREDA is still under process. Power division is to facilitate the development of renewable energy until SREDA is formed.

While the power sector in Bangladesh has witnessed many success stories in the last couple of years, the road that lies ahead is dotted with innumerable challenges that result from the gaps that exist between what’s planned versus what the power sector has been able to deliver. There is no doubt that the demand for electricity is increasing rapidly with the improvement of living standard, increase of agricultural production, progress of industries as well as overall development of the country.

Power Generation Scenery in Bangladesh

Severe power crisis compelled the Government to enter into contractual agreements for high-cost temporary solution, such as rental power and small IPPs, on an emergency basis, much of it diesel or liquid-fuel based. This has imposed tremendous fiscal pressure. With a power sector which is almost dependent on natural-gas fired generation (89.22%), the country is confronting a simultaneous shortage of natural gas and electricity. Nearly 400-800 MW of power could not be availed from the power plants due to shortage of gas supply. Other fuels for generating low-cost, base-load energy, such as coal, or renewable source like hydropower, are not readily available and Government has no option but to go for fuel diversity option for power generation.

When the present Government assumed the charge, the power generation was 3200 – 3400 MW against national demand of 5200 MW. In the election manifesto, government had declared specific power generation commitment of 5000 MW by 2011 and 7000 MW by 2013.

Over View of Electricity Last Couple of Year

To achieve this commitment, in spite of the major deterrents energy crisis and gas supply shortage, government has taken several initiatives to generate 6000 MW by 2011, 10,000 MW by 2013 and 15,000 MW by 2016, which are far beyond the commitment in the election manifesto. 2944 MW of power (as of Jan, 2012) has already been added to the grid within three years time. The government has already developed Power system Master Plan 2010. According to the Master Plan the forecasted demand would be 19,000 MW in 2021 and 34,000 MW in 2030. To meet this demand the generation capacity should be 39,000 MW in 2030. The plan suggested going for fuel-mixed option, which should be domestic coal 30%, imported coal 20 %, natural gas (including LNG) 25%, liquid fuel 5%, nuclear, renewable energy and power import 20%. In line with the Power system Master Plan 2010, an interim generation plan up to 2016 has been prepared, which is as follows:

Table 01: Plants Commissioned During 2009-2011

Power Generation Sector

2009 (MW)

2010 (MW)

2011 (MW)

TOTAL (MW)

Public

 –

255

800

1055

Private

356

270

125

751

Q. Rental

 –

250

838

1088

Total

356

775

1763

2894

  *In 2011, 1763 MW commissioned against plan for 2194 MW

Power Generation Units (fuel Type Wise)

Table 02: Installed Capacity of BPDB Power Plants as on April 2012

Plant Type

Total Capacity (in MW)

(%) Percentage in total developed power

Gas

5086.00 MW

75.99 %

HSD

682.00MW

10.19%

HFO

335.00 MW

5.01 %

Coal

250.00MW

3.74%

Hydro

230.00 MW

3.44 %

F.Oil

110.00MW

1.64%

Total

6693.00MW

100%

Table 03: Dreaded Capacity of BPDPB Power Plants as on April 2012

Plant Type

Total Capacity (in MW)

(%) Percentage in total developed power

Gas

4651.00 MW

76.74 %

HSD

657.00MW

10.84%

HFO

248.00 MW

4.09 %

Coal

200.00MW

3.3%

Hydro

220.00 MW

3.63 %

F.Oil

85.00MW

1.4%

Total

6061.00MW

100%

OWNER WISE DALY GENERATION REPORT

Table 04: Daily Generation of 25/04/2012

Owner Name

Derated Capacity(MW)

Day Peak(MW)

Eve. Peak(MW)

PDB

3209.00

1311.00

1516.00

SUB,PDB

223.00

51.00

104.00

EGCB

210.00

80.00

86.00

APSCL

662.00

539.00

567.00

IPP

1260.00

1021.00

1196.00

SIPP,REB

110.00

97.00

81.00

Rental(3 years)

33.00

15.00

0.00

SIPP,REB

215.00

150.00

156.00

Q.Rental 3Years

250.00

162.00

203.00

Rental 15 years

21.00

20.00

13.00

QRPP(5yars)

315.00

136.00

304.00

Others

0.00

49.00

60.00

RPP (3YEARS)

420.00

172.00

281.00

QRPP(3YEARS)

476.00

196.00

198.00

RPP(15YARS)

147.00

125.00

134.00

Total

7551.00

4124.00

4899.00

Table 05: Maximum Generation: Last Six Year

Maximum generation in 2012

6066.00MW as on 22-03-2012

Maximum generation in 2011

5174.00MW as on 23-11-2011

Maximum generation in 2010

4698.50MW as on 20-082010

Maximum generation in 2009

4296.00MW as on 18-09-2009

Maximum generation in 2008

4036.70MW as on 19-09-2008

Maximum generation in 2007

4130.00MW as on 17-09-2007

Maximum generation in history

6066.00MW as on 2908-2011

Electricity Demand and Supply

Per capita generation of electricity in Bangladesh is now about 252KWh. In view of the prevailing low consumption base in Bangladesh, a high growth rate in energy and electricity is indispensable for facilitating smooth transition from subsistence level of economy to the development threshold. The average annual growth in peak demand of the national grid over the last three decades was about 8.5%. It is believed that the growth is still suppressed by shortage of supply. Desired growth is generation is hampered, in addition to financial constraints, by inadequacy in supply of primary energy resources. The strategy adopted during the energy crisis was to reduce dependence on imported oil through its replacement by indigenous fuel. Thus almost all plants built after the energy crises were based on natural gas as fuel. Preference for this fuel is further motivated by its comparatively low tariff for power generation.

 Power Demand Forecasts (2010-2030)

The adoption scenarios of the power demand forecast in this MP are as shown in the figure below.

The figure indicates three scenarios; (i) GDP 7% scenario and (ii) GDP 6% scenario, based on energy intensity method, and (iii) government policy scenario.

 

FY

Government Policy Scenario

Comparison GDP (7%)

                  Scenario

Comparison GDP (6%)        Scenario

Peak Demand

     (MW)

Generation

   (GWH)

Peak Demand

      (MW)

Generation

     (GWH)

Peak Demand

   ( MW)

Generation

    (GWH)

2010

6454

33922

6454

33922

6454

33922

2011

6765

35557

6869

36103

6756

35510

2012

7518

39515

7329

38521

7083

37228

2013

8349

43882

7837

41191

7436

39084

2014

9268

48713

8398

44140

7819

41097

2015

10283

54047

9019

47404

8232

43267

2016

11405

59945

9705

51009

8680

45622

2017

12644

66457

10463

54994

9165

48171

2018

14014

73658

11300

59393

9689

50925

2019

15527

81610

12224

64249

10255

53900

2020

17304

90950

13244

69610

10868

57122

2021

18838

99838

14249

75517

11442

60640

2022

20443

109239

15344

81992

12056

64422

2023

21993

118485

16539

89102

12713

68490

2024

23581

128073

17840

96893

13416

72865

2025

25199

137965

19257

105432

14167

77564

2026

26838

148114

20814

114868

14979

82666

2027

28487

158462

22509

125209

15848

88156

2028

30134

168943

24353

136533

16776

94053

2029

31873

180089

26358

148928

17768

100393

2030

33708

191933

28537

162490

18828

107207

Table 06: Demand Forecast (3scenario)

Source: Power System Master Plan (PSMP) Study Team

FY- Forecast year*

INSTALLED CAPACITY

NEW GENERATION PLAN OF THE GOVERNMENT (From 2012 to2016) In MW

Power is the precondition for social and economic development. But currently consumers cannot be provided with uninterrupted and quality power supply due to inadequate generation compared to the national demand. To fulfill the commitment as declared in the Election Manifesto and to implement the Power Sector Master Plan 2010, Government has already been taken massive generation, transmission and distribution plan. The generation target up to 2016 is given below:

YEAR

2012

2013

2014

2015

2016

       TOTAL

PUBLIC

632MW

1467MW

1660MW

1410MW

750MW

5919MW

PRIVET

1354MW

1372MW

1637MW

772MW

1600MW

6735MW

IMPORT

0

500MW

0

0

0

500MW

TOTAL

1986MW

3339MW

3297MW

2182MW

2350MW

13154MW

Table 07: Power generation addition from 2009-11

     *2894 MW Power Generation addition from January 2009 to December 2011

Government Upcoming Nearest plan

Government has taken short, medium and long term plan. Under the short term plan, Quick Rental Power Plants will be installed using liquid fuels/gas and capable to produce electricity within 12-24 months. Nearly 1753 MW is planned to be generated from rental and quick rental power plants.

Under the medium term plan, initiatives have been taken to set up power plants with a total generation capacity of 7919 MW that is implementable within 3 to 5 years time. The plants are mainly coal based; some are gas and oil based. In the long term plan, some big coal fired plants will be set up, one will be in Khulna South and other will be in Chittagong, each of having the capacity of 1300 MW. Some 300-450 MW plants will be set up in Bibiana, Meghnaghat, Ashugonj, Sirangonj and in Ghorashal. If the implementation of the plan goes smoothly, it will be possible to minimize the demand-supply gap at the end of 2012.

Government has already started implementation of the plan. Total 31,355 Million-kilowatt hour (MkWh) net energy was generated during 2010-11. Public sector power plant generated 47% while private sector generated 53% of total net generation. The share of gas, hydro, coal and oil based energy generation was 82.12%, 2.78%, 2.49% and 12.61% respectively. On the other hand, in FY 2009-10, 29,247 million-kilowatt hour (MkWh) net energy was generated i.e. electricity growth rate in FY 2011 was 7.21% (In FY 2012 (Jul-Dec, 2011) is 13.2%).

Why do we select this project?

Now fuel crises are increasing day by day in worldwide and it impacts on energy sector to produce or generate electricity. Big amount of fuel from total reserved of fuel in our country is used to generate electricity.

Therefore the reserved fuel will be finish in the future. Analysis are thinking to make the strong energy sector with the rentable energy is one of the major part of the renewable energy to produce electricity and that is why we have chosen the solar energy system.

The solar system is constructed with various types of ingredients. But here the battery is the heart of the solar system. The solar energy is not used directly and it is used with the help of the battery because we get very low D.C voltage from the solar panel. Therefore we need to use the battery to store this low D.C voltage which is supplied from the solar panel. In a solar system, the 50% cost is expense for the battery from its total cost. Since the battery is a major part of the solar system and it is charged perfectly by a controller circuit. If the battery is not charged perfectly then the charge capacity will be decreasing in a very short time and it also can be damaged for the overcharging.

We have chosen the battery charge controller system by considering above reason.

An Introduction to Solar Energy

 The interest in renewable energy has been revived over last few year, especially after global awareness regarding the ill effects of fossil fuel burning. Energy is the source of growth and the mover for economic and social development of a nation and its people. No matter how we cry about development or poverty alleviation it is not going to come until lights are provided to our people for seeing, reading and working.

Natural resources or energy sources such as; fossil fuels, oil natural gas, etc. are completely used or economically depleted. Because we are rapidly exhausting, our non-renewable resources, degrading the potentially renewable resources and even threatening the perpetual resources. It demands immediate attention especially in the third world countries, where only scarce resources are available for an enormous size of population. The civilization is dependent on electric power. There is a relationship between GDP growth rate and electricity growth rate in a country.

Clearly, the present gas production capacity in Bangladesh can’t support both domestic gas needs,  as well as wider electricity generation for the country . On September 15th 2009, the Power Division of the Ministry of Power, Energy  and Mineral Resources of Bangladesh pushed for urgent action to be taken to improve the country’s energy outlook. The Power Division made recommendation such as ceasing gas supply to gas-fired power plants after 2012 to conserve gas reserves for domestic use.

The Government of Bangladesh is actively engaged in energy crisis management. The National Energy Policy has the explicit goal of supplying the whole country with electricity by 2020. Since 1996, the government has allowed private, independent power producer to enter the Bangladeshi market. It is already importing 100 Megawatts of power from India and has negotiated with private companies renting plants to buy power at higher rates.

It is impossible to conceive development of civilization without “Energy”.Densely populated country like Bangladesh can only sustain and progress if only latest energy technologies can be used efficiently. Government of Bangladesh is working towards achieving “Power i.e. Electricity for All” by the year 2020.Bangladesh is one of the most severely affected counties of the World due to climate change and global warming effects.

What Is Solar Energy?

Solar energy is energy that comes from the sun. Every day the sun radiates, or sends out, an enormous amount of energy. The sun radiates more energy in one second than people have used since the beginning of time!

Where does all this energy come from? It comes from within the sun itself. Like other stars, the sun is a big gas ball made up mostly of hydrogen and helium. The sun generates energy in its core in a process called nuclear fusion. During nuclear fusion, the sun’s extremely high pressure and hot temperature cause hydrogen atoms to come apart and their nuclei (the central cores of the atoms) to fuse or combine. Four hydrogen nuclei fuse to become one helium atom. But the helium atom weighs less than the four nuclei that combined to form it. Some matter is lost during nuclear fusion. The lost matter is emitted into space as radiant energy.

It takes millions of years for the energy in the sun’s core to make its way to the solar surface, and then just a little over eight minutes to travel the 93 million miles to earth. The solar energy travels to the earth at a speed of 186,000 miles per second, the speed of light. Only a small portion of the energy radiated by the sun into space strikes the earth, one part in two billion. Yet this amount of energy is enormous. Every day enough energy strikes the United States to supply the nation’s energy needs for one and a half years!

Where does all this energy go? About 15 percent of the sun’s energy that hits the earth is reflected back into space. Another 30 percent is used to evaporate water, which, lifted into the atmosphere, produce’s rain-fall. Solar energy also is absorbed by plants, the land, and the oceans. The rest could be used to supply our energy needs.

History of Solar Energy

People have harnessed solar energy for centuries. As early as the 7th century B.C., people used simple magnifying glasses to concentrate the light of the sun into beams so hot they would cause wood to catch fire. Over 100 years ago in France, a scientist used heat from a solar collector to make steam to drive a steam engine.

In the beginning of this century, scientists and engineers began researching ways to use solar energy in earnest. One important development was a remarkably efficient solar boiler invented by Charles Greeley Abbott, an American astrophysicist, in 1936.

The solar water heater gained popularity at this time in Florida, California, and the Southwest. The industry started in the early 1920s and was in full swing just before World War 11. This growth lasted until the mid- 1950s when low-cost natural gas became the primary fuel for heating American homes. The public and world governments remained largely indifferent to the possibilities of solar energy until the oil shortages of the 1970s. Today people use solar energy to heat buildings and water and to generate electricity.

Utilization of solar Energy

Solar energy, radiant light and heat from the sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available renewable energy on earth. Only a minuscule fraction of the available solar energy is used.

Solar powered electrical generation relies on heat engines and photovoltaic. Solar energy’s uses are limited only by human ingenuity. A partial list of solar applications includes space heating and cooling through solar architecture, potable water via distillation and disinfection, day lighting, solar hot water, solar cooking, and high temperature process heat for industrial purposes. To harvest the solar energy, the most common way is to use solar panels.

Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.

There are main two ways we can produce electricity from the sun:

Photovoltaic Electricity – This method uses photovoltaic cells that absorb the direct sunlight just like the solar cells you see on some calculators.

Solar Thermal Electricity – This also uses a solar collector: it has a mirrored surface that reflects the sunlight onto a receiver that heats up a liquid. This heated liquid is used to make steam that produces electricity.

Solar System Descriptions

In today’s climate of growing energy needs and increasing environmental concern, alternatives to the use of non-renewable and polluting fossil fuels have to be investigated. One such alternative is solar energy.

Solar energy is quite simply the energy produced directly by the sun and collected elsewhere, normally the Earth. The sun creates its energy through a thermonuclear process that converts about 650,000,0001 tons of hydrogen to helium every second. The process creates heat and electromagnetic radiation. The heat remains in the sun and is instrumental in maintaining the thermonuclear reaction. The electromagnetic radiation (including visible light, infra-red light, and ultra-violet radiation) streams out into space in all directions.

Only a very small fraction of the total radiation produced reaches the Earth. The radiation that does reach the Earth is the indirect source of nearly every type of energy used today. The exceptions are geothermal energy, and nuclear fission and fusion. Even fossil fuels owe their origins to the sun; they were once living plants and animals whose life was dependent upon the sun.

Much of the world’s required energy can be supplied directly by solar power. More still can be provided indirectly. The practicality of doing so will be examined, as well as the benefits and drawbacks. In addition, the uses solar energy is currently applied to will be noted.

Due to the nature of solar energy, two components are required to have a functional solar energy generator. These two components are a collector and a storage unit. The collector simply collects the radiation that falls on it and converts a fraction of it to other forms of energy (either electricity and heat or heat alone). The storage unit is required because of the non-constant nature of solar energy; at certain times only a very small amount of radiation will be received. At night or during heavy cloud cover, for example, the amount of energy produced by the collector will be quite small. The storage unit can hold the excess energy produced during the periods of maximum productivity, and release it when the productivity drops. In practice, a backup power supply is usually added, too, for the situations when the amount of energy required is greater than both what is being produced and what is stored in the container.

Methods of collecting and storing solar energy vary depending on the uses planned for the solar generator. In general, there are three types of collectors and many forms of storage units.

The three types of collectors are flat-plate collectors, focusing collectors, and passive collectors.

Flat-plate collectors are the more commonly used type of collector today. They are arrays of solar panels arranged in a simple plane. They can be of nearly any size, and have an output that is directly related to a few variables including size, facing, and cleanliness. These variables all affect the amount of radiation that falls on the collector. Often these collector panels have automated machinery that keeps them facing the sun. The additional energy they take in due to the correction of facing more than compensates for the energy needed to drive the extra machinery.

Focusing collectors are essentially flat-plane collectors with optical devices arranged to maximize the radiation falling on the focus of the collector. These are currently used only in a few scattered areas. Solar furnaces are examples of this type of collector. Although they can produce far greater amounts of energy at a single point than the flat-plane collectors can, they lose some of the radiation that the flat-plane panels do not. Radiation reflected off the ground will be used by flat-plane panels but usually will be ignored by focusing collectors (in snow covered regions, this reflected radiation can be significant). One other problem with focusing collectors in general is due to temperature. The fragile silicon components that absorb the incoming radiation lose efficiency at high temperatures, and if they get too hot they can even be permanently damaged. The focusing collectors by their very nature can create much higher temperatures and need more safeguards to protect their silicon components.

Passive collectors are completely different from the other two types of collectors. The passive collectors absorb radiation and convert it to heat naturally, without being designed and built to do so. All objects have this property to some extent, but only some objects (like walls) will be able to produce enough heat to make it worthwhile. Often their natural ability to convert radiation to heat is enhanced in some way or another (by being painted black, for example) and a system for transferring the heat to a different location is generally added.

People use energy for many things, but a few general tasks consume most of the energy. These tasks include transportation, heating, cooling, and the generation of electricity. Solar energy can be applied to all four of these tasks with different levels of success.

Heating is the business for which solar energy is best suited. Solar heating requires almost no energy transformation, so it has a very high efficiency. Heat energy can be stored in a liquid, such as water, or in a packed bed. A packed bed is a container filled with small objects that can hold heat (such as stones) with air space between them. Heat energy is also often stored in phase-change or heat-of-fusion units. These devices will utilize a chemical that changes phase from solid to liquid at a temperature that can be produced by the solar collector. The energy of the collector is used to change the chemical to its liquid phase, and is as a result stored in the chemical itself. It can be tapped later by allowing the chemical to revert to its solid form. Solar energy is frequently used in residential homes to heat water. This is an easy application, as the desired end result (hot water) is the storage facility. A hot water tank is filled with hot water during the day, and drained as needed. This application is a very simple adjustment from the normal fossil fuel water heaters.

Swimming pools are often heated by solar power. Sometimes the pool itself functions as the storage unit, and sometimes a packed bed is added to store the heat. Whether or not a packed bed is used, some method of keeping the pool’s heat for longer than normal periods (like a cover) is generally employed to help keep the water at a warm temperature when it is not in use.

Solar energy is often used to directly heat a house or building. Heating a building requires much more energy than heating a building’s water, so much larger panels are necessary. Generally a building that is heated by solar power will have its water heated by solar power as well. The type of storage facility most often used for such large solar heaters is the heat-of-fusion storage unit, but other kinds (such as the packed bed or hot water tank) can be used as well. This application of solar power is less common than the two mentioned above, because of the cost of the large panels and storage system required to make it work. Often if an entire building is heated by solar power, passive collectors are used in addition to one of the other two types. Passive collectors will generally be an integral part of the building itself, so buildings taking advantage of passive collectors must be created with solar heating in mind.

These passive collectors can take a few different forms. The most basic type is the incidental heat trap. The idea behind the heat trap is fairly simple. Allow the maximum amount of light possible inside through a window (The window should be facing towards the equator for this to be achieved) and allow it to fall on a floor made of stone or another heat holding material. During the day, the area will stay cool as the floor absorbs most of the heat, and at night, the area will stay warm as the stone re-emits the heat it absorbed during the day. Another major form of passive collector is thermos phonin walls and/or roof. With this passive collector, the heat normally absorbed and wasted in the walls and roof is re-routed into the area that needs to be heated.

The last major form of passive collector is the solar pond. This is very similar to the solar heated pool described above, but the emphasis is different. With swimming pools, the desired result is a warm pool. With the solar pond, the whole purpose of the pond is to serve as an energy regulator for a building. The pond is placed either adjacent to or on the building, and it will absorb solar energy and convert it to heat during the day. This heat can be taken into the building, or if the building has more than enough heat already, heat can be dumped from the building into the pond.

Solar energy can be used for other things besides heating. It may seem strange, but one of the most common uses of solar energy today is cooling. Solar cooling is far more expensive than solar heating, so it is almost never seen in private homes. Solar energy is used to cool things by phase changing a liquid to gas through heat, and then forcing the gas into a lower pressure chamber. The temperature of a gas is related to the pressure containing it, and all other things being held equal, the same gas under a lower pressure will have a lower temperature. This cool gas will be used to absorb heat from the area of interest and then be forced into a region of higher pressure where the excess heat will be lost to the outside world. The net effect is that of a pump moving heat from one area into another, and the first is accordingly cooled.

Besides being used for heating and cooling, solar energy can be directly converted to electricity. Most of our tools are designed to be driven by electricity, so if you can create electricity through solar power, you can run almost anything with solar power. The solar collectors that convert radiation into electricity can be either flat-plane collectors or focusing collectors, and the silicon components of these collectors are photovoltaic cells.

Photovoltaic cells, by their very nature, convert radiation to electricity. This phenomenon has been known for well over half a century, but until recently the amounts of electricity generated were good for little more than measuring radiation intensity. Most of the photovoltaic cells on the market today operate at an efficiency of less than 15%; that is, of all the radiation that falls upon them, less than 15% of it is converted to electricity. The maximum theoretical efficiency for a photovoltaic cell is only 32.3%, but at this efficiency, solar electricity is very economical. Most of our other forms of electricity generation are at a lower efficiency than this.

Unfortunately, reality still lags behind theory and a 15% efficiency is not usually considered economical by most power companies, even if it is fine for toys and pocket calculators. Hope for bulk solar electricity should not be abandoned, however, for recent scientific advances have created a solar cell with an efficiency of 28.2% efficiency in the laboratory. This type of cell has yet to be field-tested. If it maintains its efficiency in the uncontrolled environment of the outside world, and if it does not have a tendency to break down, it will be economical for power companies to build solar power facilities after all.

Of the main types of energy usage, the least suited to solar power is transportation. While large, relatively slow vehicles like ships could power themselves with large onboard solar panels, small constantly turning vehicles like cars could not. The only possible way a car could be completely solar powered would be through the use of battery that was charged by solar power at some stationary point and then later loaded into the car. Electric cars that are partially powered by solar energy are available now, but it is unlikely that solar power will provide the world’s transportation costs in the near future.

Solar power has two big advantages over fossil fuels. The first is in the fact that it is renewable; it is never going to run out. The second is its effect on the environment.

While the burning of fossil fuels introduces many harmful pollutants into the atmosphere and contributes to environmental problems like global warming and acid rain, solar energy is completely non-polluting. While many acres of land must be destroyed to feed a fossil fuel energy plant its required fuel, the only land that must be destroyed for a solar energy plant is the land that it stands on. Indeed, if a solar energy systems were incorporated into every business and dwelling, no land would have to be destroyed in the name of energy. This ability to decentralize solar energy is something that fossil fuel burning cannot match.

As the primary element of construction of solar panels, silicon, is the second most common element on the planet, there is very little environmental disturbance caused by the creation of solar panels. In fact, solar energy only causes environmental disruption if it is centralized and produced on a gigantic scale. Solar power certainly can be produced on a gigantic scale, too. Among the renewable resources, only in solar power do we find the potential for an energy source capable of supplying more energy than is used.

Suppose that of the 4.5×1017 kWh per annum that is used by the earth to evaporate water from the oceans we were to acquire just 0.1% or 4.5×1014 kWh per annum. Dividing by the hours in the year gives a continuous yield of 2.90×1010 kW. This would supply 2.4 kW to 12.1 billion people.

This translates to roughly the amount of energy used today by the average American available to over twelve billion people. Since this is greater than the estimated carrying capacity of the Earth, this would be enough energy to supply the entire planet regardless of the population.

Unfortunately, at this scale, the production of solar energy would have some unpredictable negative environmental effects. If all the solar collectors were placed in one or just a few areas, they would probably have large effects on the local environment, and possibly have large effects on the world environment. Everything from changes in local rain conditions to another Ice Age has been predicted as a result of producing solar energy on this scale. The problem lies in the change of temperature and humidity near a solar panel; if the energy producing panels are kept non-centralized, they should not create the same local, mass temperature change that could have such bad effects on the environment.

Of all the energy sources available, solar has perhaps the most promise. Numerically, it is capable of producing the raw power required to satisfy the entire planet’s energy needs. Environmentally, it is one of the least destructive of all the sources of energy. Practically, it can be adjusted to power nearly everything except transportation with very little adjustment, and even transportation with some modest modifications to the current general system of travel. Clearly, solar energy is a resource of the future.

Advantage of Solar Energy:

  1. Technology is easy
  2. Affordable cost
  3. Within the ability of poor’s
  4. Basically no maintenance cost
  5. Only source of energy is sunshine
  6. Energy source is cost free
  7. Environmental Pollution is less
  8. No emission
  9. Very few materials are required

CHAPTER 03

Theory of solar cell charge Circuit

Equivalent circuit of a solar cell

To understand the electronic behavior of a solar cell, it is useful to create a model which is electrically equivalent, and is based on discrete electrical components whose behavior is well known. An ideal solar cell may be modeled by a current source in parallel with a diode; in practice no solar cell is ideal, so a shunt resistance and a series resistance component are added to the model. The resulting equivalent circuit of a solar cell is shown on the left. Also shown, on the right, is the schematic representation of a solar cell for use in circuit diagrams.

Characteristic equation

From the equivalent circuit it is evident that the current produced by the solar cell is equal to that produced by the current source, minus that which flows through the diode, minus that which flows through the shunt resistor:

I = IL − ID − ISH       

Where

  • § I = output current (amperes)
  • § IL = photo generated current (amperes)
  • § ID = diode current (amperes)
  • § ISH = shunt current (amperes).

The current through these elements is governed by the voltage across them:

Vj = V + IRS

Where

  •  Vj = voltage across both diode and resistor RSH (volts)
  •  V = voltage across the output terminals (volts)
  •  I = output current (amperes)
  •  RS = series resistance (Ω).

By the Shockley diode equation, the current diverted through the diode is:

Where

  •  I0 = reverse saturation current (amperes)
  • n = diode ideality factor (1 for an ideal diode)
  •  q = elementary charge
  •  k = Boltzmann’s constant
  •  T = absolute temperature
  • At 25°C,  volts.

By Ohm’s law, the current diverted through the shunt resistor is:

Where

  • § RSH = shunt resistance (Ω).

Substituting these into the first equation produces the characteristic equation of a solar cell, which relates solar cell parameters to the output current and voltage:

An alternative derivation produces an equation similar in appearance, but with V on the left-hand side. The two alternatives are identities; that is, they yield precisely the same results.

In principle, given a particular operating voltage V the equation may be solved to determine the operating current I at that voltage. However, because the equation involves I on both sides in a transcendental function the equation has no general analytical solution. However, even without a solution it is physically instructive. Furthermore, it is easily solved using numerical methods. (A general analytical solution to the equation is possible using Lambert’s W function, but since Lambert’s W generally itself must be solved numerically this is a technicality.)Since the parameters I0, n, RS, and RSH cannot be measured directly, the most common application of the characteristic equation is nonlinear regression to extract the values of these parameters on the basis of their combined effect on solar cell behavior.

 Basic Battery Charging Methods

Constant Voltage a constant voltage charger is basically a DC power supply which in its simplest form may consist of a step down transformer from the mains with a rectifier to provide the DC voltage to charge the battery. Such simple designs are often found in cheap car battery chargers. The lead-acid cells used for cars and backup power systems typically use constant voltage chargers. In addition, lithium-ion cells often use constant voltage systems, although these usually are more complex with added circuitry to protect both the batteries and the user safety.

Constant Current Constant current chargers vary the voltage they apply to the battery to maintain a constant current flow, switching off when the voltage reaches the level of a full charge. This design is usually used for nickel-cadmium and nickel-metal hydride cells or batteries.

Taper Current this is charging from a crude unregulated constant voltage source. It is not a controlled charge as in V Taper above. The current diminishes as the cell voltage (back emf) builds up. There is a serious danger of damaging the cells through overcharging. To avoid this charging rate and duration should be limited. Suitable for SLA batteries only.

Pulsed charge Pulsed chargers feed the charge current to the battery in pulses. The charging rate (based on the average current) can be precisely controlled by varying the width of the pulses, typically about one second. During the charging process, short rest periods of 20 to 30 milliseconds, between pulses allow the chemical actions in the battery to stabilize by equalizing the reaction throughout the bulk of the electrode before recommencing the charge. This enables the chemical reaction to keep pace with the rate of inputting the electrical energy. It is also claimed that this method can reduce unwanted chemical reactions at the electrode surface such as gas formation, crystal growth and passivation. (See also Pulsed Charger below). If required, it is also possible to sample the open circuit voltage of the battery during the rest period.

Burp charging also called Reflex or Negative Pulse Charging Used in conjunction with pulse charging, it applies a very short discharge pulse, typically 2 to 3 times the charging current for 5 milliseconds, during the charging rest period to depolarize the cell. These pulses dislodge any gas bubbles which have built up on the electrodes during fast charging, speeding up the stabilization process and hence the overall charging process. The release and diffusion of the gas bubbles is known as “burping”. Controversial claims have been made for the improvements in both the charge rate and the battery lifetime as well as for the removal of dendrites made possible by this technique. The least that can be said is that “it does not damage the battery”.

IUI Charging this is a recently developed charging profile used for fast charging standard flooded lead acid batteries from particular manufacturers. It is not suitable for all lead acid batteries. Initially the battery is charged at a constant (I) rate until the cell voltage reaches a preset value – normally a voltage near to that at which gassing occurs. This first part of the charging cycle is known as the bulk charge phase. When the preset voltage has been reached, the charger switches into the constant voltage (U) phase and the current drawn by the battery will gradually drop until it reaches another preset level. This second part of the cycle completes the normal charging of the battery at a slowly diminishing rate. Finally the charger switches again into the constant current mode (I) and the voltage continue to rise up to a new higher preset limit when the charger is switched off. This last phase is used to equalize the charge on the individual cells in the battery to maximize battery life. See Cell Balancing.

Trickle charge Trickle charging is designed to compensate for the self discharge of the battery. Continuous charge. Long term constant current charging for standby use. The charge rate varies according to the frequency of discharge. Not suitable for some battery chemistries, e.g. NiMH and Lithium, which are susceptible to damage from overcharging In some applications the charger is designed to switch to trickle charging when the battery is fully charged.

Float charge. The battery and the load are permanently connected in parallel across the DC charging source and held at a constant voltage below the battery’s upper voltage limit. Used for emergency power back up systems. Mainly used with lead acid batteries.

Random charging All of the above applications involve controlled charge of the battery, however there are many applications where the energy to charge the battery is only available, or is delivered, in some random, uncontrolled way. This applies to automotive applications where the energy depends on the engine speed which is continuously changing. The problem is more acute in EV and HEV applications which use regenerative braking since this generates large power spikes during braking which the battery must absorb. More benign applications are in solar panel installations which can only be charged when the sun is shining. These all require special techniques to limit the charging current or voltage to levels which the battery can tolerate.

Charge controller

A charge controller, charge regulator or battery regulator limits the rate at which electric current is added to or drawn from electric batteries.  It prevents overcharging and may prevent against overvoltage, which can reduce battery performance or lifespan, and may pose a safety risk. It may also prevent completely draining (“deep discharging”) a battery, or perform controlled discharges, depending on the battery technology, to protect battery life.   The terms “charge controller” or “charge regulator” may refer to either a stand-alone device, or to control circuitry integrated within a battery pack, battery-powered device, or battery recharger.

Charge controllers are sold to consumers as separate devices, often in conjunction with solar or wind power generators, for uses such as RV, boat, and off-the-grid home battery storage systems.   In solar applications, charge controllers may also be called solar regulators.  

A series charge controller or series regulator disables further current flow into batteries when they are full. A shunt charge controller or shunt regulator diverts excess electricity to an auxiliary or “shunt” load, such as an electric water heater, when batteries are full.  

Simple charge controllers stop charging a battery when they exceed a set high voltage level, and re-enable charging when battery voltage drops back below that level. Pulse width modulation (PWM) and maximum power point tracker (MPPT) technologies are more electronically sophisticated, adjusting charging rates depending on the battery’s level, to allow charging closer to its maximum capacity Charge controllers may also monitor battery temperature to prevent overheating. Some charge controller systems also display data; transmit data to remote displays, and data logging to track electric flow over time.

Circuitry that functions as a charge regulator controller may consist of several electrical components, or may be encapsulated in a single microchip, an integrated circuit (IC) usually called a charge controller IC or charge control IC

Charge controller circuits are used for rechargeable electronic devices such as cell phones, laptop computers, portable audio players, and uninterruptible power supplies, as well as for larger battery systems found in electric vehicles and orbiting space satellites. Charge controller circuitry may be located in the battery-powered device, in a battery pack for either wired or wireless (inductive) charging, in line with the wiring,or in the AC adapter or other power supply module.

CHAPTER 04

Design and Operation

 

Working principal of Solar Charge Controller:

The overall circuit can be divided by the following major parts:

  1. IC SG 3524
  2.  IC LM358
  3. Relay
  4. MOSFET
  5. Input/output Ports

The working principles of those major parts are provided below:

  1. IC- SG 3524: This is the heart of the controller circuit. The IC has 16 numbers of pins.
  • The Pin numbers 1 and 9 are mainly used for the controlling purpose.
  • The Pin numbers 6 and 7 work as a Pulse Width Modulator.
  • The Pin numbers 4, 5 and 8 used for grounding purpose.
  • The Pin number 11 and 14 are used to MOSFET triggering.
  • The Pin numbers 12, 13 used as collector.
  • The Pin numbers 2, 3, 10 and 16 not in used.
  • The Pin number 15 used to input voltage.

Here a 10k variable resister is used to increase and decrease the width of the pulses.

If the width of the pulse is increased then current becomes high current will be low when the width of the pulse is decreased.

  1. IC-LM 358: This is an Operational Amplifier IC used to general purpose of amplification. The IC has 8 numbers of pins.
  • The Pin number 1 provides the desire outputs to the relay unit.
  • The Pin number 2 get constant supply 5.1 volts from zener diode.
  • The Pin number 3 used as non inverting input.

Here a 10K variable register is used to select the value of the changing voltage.

Relay Unit: The relay of 12V DC which maintains a very important role for charge controlling. The magnetic contact of the relay energized when is depending with the charging period of OFF-ON. If charge is decreased then it becomes ON with the help of magnetic contact. If the battery is fully charged then it goes into the OFF mode. The diode IN4007 is used across the relay to defuse the back emf which is produced in the relay. It is very important for protection the relay.

 MOSFET: Here two N-channel MOSFET have been used because we are controlling the (-ve) terminal of the circuit. These two MOSFET are used to get higher current in the circuit. It is not possible to use more than two MOSFET because the pins 14N0 and 11N0 of I.C SG3524 are triggering the gate of MOSFET. There is a 10k variable resistor in this MOSFET which is used to select the max rating of the battery.

 Input/output Port: There are three ports in this circuit which are as follows:

  1. Solar Input Port
  2.  Battery Output Port
  3. DC Output Port

A very small amount of current produce in the solar cells when sun light hit the panel. The charging circuit collects those current by the solar input port.

The negative of the DC which controlled by the charging circuit meets with the negative of the battery output port. On the other side positive of the DC connected with the positive of the batter output port.

The battery output port provides the conventional DC to the battery. The DC output port provides   12 volts DC supply.

Solar Charge Controller Circuit Rating

Maximum Power

 

12.5 Watts

 

Maximum Power Voltage

21 Volts

Maximum Power Current

0.6 Ampere

Short Circuit Current

1.02 Ampere

Open Circuit Voltage

24.6 Volts

Operating Temperature

40—C

Required apparatus:

1. IC-SG3524

2. IC-LM358

3. Relay D.C (12v)

4. Transistor (NPN) B.C547

5. Zener diode 5.1v

6. Diode

* 1N4007, 1N5408

7. Variable resistor 10K

8. Capacitor

* 10µF, 1 µF

9. Resistor

* 1K, 10K , 100K, 47K, 22K, 150K

IC-SG3524:  

INVERT INPUT 1 16 VREF
NON-INV INPUT 2 15 VIN
OSC OUTPUT 3 14 EMITTER B
(+)CL SENSE 4 13 COLLECTOR B
(±)CL SENSE 5 12 COLLECTOR A
RT 6 11 EMITTER A
CT 7 10 SHUTDOWN
GROUND 8 9 COMPENSATION

 

 

 

 

 

 

 

DESCRIPTION

This monolithic integrated circuit contains all the control circuitry for a regulating power supply inverter or switching regulator. Included in a 16-pin dual-in-line package is the voltage reference, error amplifier, oscillator, pulse-width modulator, pulse steering flip-flop, dual alternating output switches and current-limiting and shut-down circuitry. This device can be used for switching regulators of polarity, transformer-coupled DC-to-DC converters, transformer less voltage doublers and polarity converters, as well as other power control applications. The SG3524 is designed for commercial applications of 0C to +70C.

FEATURES

Complete PWM power control circuitry

Single ended or push-pull outputs

Line and load regulation of 0.2%

1% maximum temperature variation

Total supply current is less than 10mA

Operation beyond 100 kHz

Description

The LM385 is a general purpose op-amp with 2 channels.

Applications include transducer amplifiers, dc amplification blocks, and all the conventional operational amplifier circuits that now can be implemented more easily in single-supply-voltage systems. For example, these devices can be operated directly from the standard 5-V supply used in digital systems and easily can provide the required interface electronics without additional ±5-V supplies

3. Relay D.C (12v) & Transistor (NPN) B.C547

Description

A relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. Relays are used where it is necessary to control a circuit by a low-power signal (with complete electrical isolation between control and controlled circuits), or where several circuits must be controlled by one signal.

Description

BC547 is an NPN bi-polar junction transistor. A transistor, stands for transfer of resistance, is commonly used to amplify current. A small current at its base controls a larger current at collector & emitter terminals.

BC547 is mainly used for amplification and switching purposes. It has a maximum current gain of 800. Its equivalent transistors are BC548 and BC549.

The transistor terminals require a fixed DC voltage to operate in the desired region of its characteristic curves. This is known as the biasing. For amplification applications, the transistor is biased such that it is partly on for all input conditions. The input signal at base is amplified and taken at the emitter. BC547 is used in common emitter configuration for amplifiers. The voltage divider is the commonly used biasing mode. For switching applications, transistor is biased so that it remains fully on if there is a signal at its base. In the absence of base signal, it gets completely off.

5. Zener diode 5.1

Description:

A Zener Diode is a special kind of diode which permits current to flow in the forward direction as normal, but will also allow it to flow in the reverse direction when the voltage is above a certain value – the breakdown voltage known as the Zener voltage. Zener diodes are useful for creating a reference voltage or as a voltage stabilizer for low-current applications. These diodes are rated for 5.1 volts with a maximum of 1W. Price is for a single diode.

6. Diod 1N4007:

General Purpose Rectifier

Features

* Low forward voltage drop.

* High surge current capability.

 

7. Variable resistor 10K

Features:

*Power: 1/4W

*Resistance: 10K Ohm

*10K oHm Trimmer , Variable Resistors/ Trim pot Potentiometer

    8. Capacitor 10µ, 1µ:

A capacitor is a passive electronic component that stores energy in the form of an electrostatic field. In its simplest form, a capacitor consists of two conducting plates separated by an insulating material called thedielectric. The capacitance is directly proportional to the surface areas of the plates, and is inversely proportional to the separation between the plates. Capacitance also depends on the dielectric constant of the substance separating the plates

1.       Resistor:

A resistor is a passive two-terminal electrical component that implements electrical resistance as a circuit element. The current through a resistor is in direct proportion to the voltage across the resistor’s terminals. Thus, the ratio of the voltage applied across a resistor’s terminals to the intensity of current through the circuit is called resistance. This relation is represented by Ohm’s law:

 11. INPUT / OUTPUT PORT:

1N5408: General Purpose Rectifiers

Features

• 3.0 ampere operation at TA = 75°C

With no thermal runaway.

• High current capability.

•Lowleak

Solar Energy Development Environmental Considerations

Benefits of Solar: SUMMARY

  • Extends the Workday

It is dark by 6:30 year round in the equatorial latitudes. Electric lighting allows families to extend their workday into the evening hours. Many villages where SELF has installed solar lights now boast home craft industries.

  • Improves Health

Fumes from kerosene lamps in poorly ventilated houses are a serious health problem in much of the world where electric light is unavailable. The World Bank estimates that 780 million women and children breathing kerosene fumes inhale the equivalent of smoke from 2 packs of cigarettes a day.

  • Stems Urban Migration

Improving the quality of life through electrification at the rural household and village level helps stem migration to mega-cities. Also, studies have shown a direct correlation between the availability of electric light and lower birth rates.

  • Improves Fire-Reduction

Kerosene lamps are a serious fire hazard in the developing world, killing and maiming tens of thousands of people each year. Kerosene, diesel fuel and gasoline stored for lamps and small generators are also a safety threat, whereas solar electric light is entirely safe.

  • Improves Literacy

Electric light improves literacy, because people can read after dark more easily than they can by candle or lamplight. Schoolwork improves and eyesight is safeguarded when children study by electric light. With the advent of television and radio, people previously cut off from electronic information, education, and entertainment can become part of the modern world without leaving home.

  • Conserves Foreign Exchange

As much as 90% of the export earnings of some developing countries are used to pay for imported oil, most of it for power generation. Capital saved by not building additional large power plants can be used for investment in health, education, economic development, and industry. Expanding solar rural electrification creates jobs and business opportunities based on an appropriate technology in a decentralized marketplace.

  • Conserves Energy

Solar electricity for the Third World is clearly the most effective energy conservation program because it conserves costly conventional power for urban areas, town market centers, and industrial and commercial uses, leaving decentralized PV-generated power to provide the lighting and basic electrical needs of the majority of the developing world’s rural populations.

  • Reduces Maintenance

Use of a SHS rather than gensets or kerosene lamps reduces the time and expense of refueling and maintenance. Kerosene lamps and diesel generators must be filled several times per day. In rural areas, purchasing and transporting of kerosene or diesel fuel is often both difficult and expensive. Diesel generators require periodic maintenance and have a short lifespan. Car batteries, used to power TVs must often be transported miles for recharging. SHS, however, require no fuel, and will last for 20 years with minimal servicing.

Benefits of Solar: HEALTH

  • Reduces kerosene-induced fires

Kerosene lamps are a serious fire hazard in the developing world, killing and maiming tens of thousands of people each year. Kerosene, diesel fuel and gasoline stored for lamps and small generators are also a safety threat, whereas solar electric light is entirely safe.

Improves indoor air quality

Fumes from kerosene lamps in poorly ventilated houses are a serious health problem in much of the world where electric light is unavailable. The World Bank estimates that 780 million women and children breathing kerosene fumes inhale the equivalent of smoke from 2 packs of cigarettes a day.

  • Increases effectiveness of health programs

Use of solar electric lighting systems by rural health centers increases the quality of health care provided. Solar electric systems improve patient diagnoses through brighter task lighting and use of electrically-lit microscopes. Photovoltaic can also power televisions and VCRs to educate health workers and patients about preventative care, medical procedures, and other health care provisions. Finally, solar electric refrigerators have a higher degree of temperature control than kerosene units, leading to lower vaccine spoilage rates, and increased immunization effectiveness.

  • Allows telemedicine

Telemedicine is the use of telecommunications technology to provide, enhance, or expedite health care services, by accessing off-site databases, linking clinics or physicians’ offices to central hospitals, or transmitting x-rays or other diagnostic images for examination at another site. Deep in the Brazilian Amazon, SELF demonstrated the feasibility of telemedicine in remote areas by using a combination of solar power and satellite communications. Within moments of plugging in the new telemedicine device, local Caboclo Indians can have meaurements of blood pressure, body temperature, pulse, and blood-oxygen uploaded via satellite to the University of Southern Alabama for remote diagnosis.

Benefits of Solar: ENVIRONMENT

  • Reduces local air pollution

Use of solar electric systems decreases the amount of local air pollution. With a decrease in the amount of kerosene used for lighting, there is a corresponding reduction in the amount of local pollution produced. Solar rural electrification also decreases the amount of electricity needed from small diesel generators.

  • Offsets greenhouse gases

Photovoltaic systems produce electric power with no carbon dioxide (CO2) emissions. Carbon emission offset is calculated at approximately 6 tons of CO2 over the twenty-year life of one PV system.

  • Conserves energy

Solar electricity for the Third World is an effective energy conservation program because it conserves costly conventional power for urban areas, town market centers, and industrial and commercial uses, leaving decentralized PV-generated power to provide the lighting and basic electrical needs of the majority of the developing world’s rural populations.

  • Reduces need for dry-cell battery disposal

Small dry-cell batteries for flashlights and radios are used throughout the unelectrified world. Most of these batteries are disposable lead-acid cells which are not recycled. Lead from disposed dry-cells leaches into the ground, contaminating the soil and water. Solar rural electrification dramatically decreases the need for disposable dry-cell batteries. Over 12 billion dry-cell batteries were sold in 1993.

Benefits of Solar: EDUCATIONAL

  • Improves literacy

Solar rural electrification improves literacy by providing high quality electric reading lights. Electric lighting is far brighter than kerosene lighting or candles. Use of solar electric light aids students in studying during evening hours.

  • Increases access to news and information

Photovoltaics give rural areas access to news and educational programming through television and radio broadcasts. With the advent of television and radio, people previously cut off from electronic information, education, and entertainment can become part of the modern world without leaving home.

  • Enables evening education classes

Ongoing education classes and adult literacy classes can be held during the evening in solar-lit community centers. SELF has electrified community centers and schools in many countries, and has witnessed the development of adult literacy and professional classes possible with the introduction of solar electric lighting systems in community centers.

  • Facilitates wireless rural telephony

Solar electricity, when coupled with wireless communications, makes it possible to introduce rural telephony and data communication services to remote villages.

  • Solar Home Systems ROLE

Rural households currently using kerosene lamps for lighting and disposable or automotive batteries for operating televisions, radios, and other small appliances are the principal market for the SHS. Solar PV is affordable to an increasing segment of the Third World’s off-grid rural populations. For home lighting, the cost of an SHS is comparable to a family’s average monthly expenditure for candles, kerosene or dry-cell batteries. Besides providing lighting, an SHS can also power a small TV. In addition, families with an SHS need no longer purchase expensive dry-cell batteries to operate its radio-cassette player, which nearly every family has. Solar PV is competitive with its alternatives: kerosene, dry-cell batteries, candles, battery re-charging from the grid, Gensets, and grid extension.

Approximately 400,000 families in the developing world are already using small, household solar PV systems to power fluorescent lights, radio-cassette players, 12 volt black-and-white TVs, and other small appliances. These families, living mostly in remote rural areas, already constitute the largest group of domestic users of solar electricity in the world. For them, there is no other affordable or immediately available source of electric power. These systems have been sold mostly by small entrepreneurs applying their working knowledge of this proven technology to serve rural families who need small amounts of power for electric lights, radios and TVs.

The success of SHS implementation has been greatly determined by quality of the components and the availability of ongoing service and maintenance. When well-designed systems have received regular ongoing maintenance they have performed successfully over many years. However, when poorly designed components have been used, or when no after-sales service was available, systems often fail. A past failure of these systems has undermined local confidence. Fly-by-night salespeople have sold thousands of substandard SHS in South Africa, for example, which failed shortly after installation. Well-designed components and after-sales service and maintenance have become recognized as essential parts of a successful PV program.

Many of these SHS were provided by non-governmental organizations (like SELF) or through government-sponsored programs with international donor support, such as in Zimbabwe where 10,000 SHS are being installed on a financed, full-cost-recovery basis (in a program designed by SELF for the United Nations in 1991.) In Bolivia, 2,500 SHS are being leased to users by a cooperative “utility.” In Kenya, over 20,000 SHS have been installed since the mid-’80’s by independent businessmen on a strictly cash basis. The World Bank estimates that 50,000 SHS have been installed in China, 40,000 in Mexico, and 20,000 in Indonesia.

According to the United Nations Development Programme, 400 million families (nearly two billion people) have no access to electricity. The European Union’s renewable energy organization EuroSolar estimates the global market for solar photovoltaic home lighting systems is 200 million families. Based on market studies in India, China, Sri Lanka, Zimbabwe, South Africa and Kenya conducted by various international development agencies over the past 5 years, the consensus is that approximately 5% of most rural populations can pay cash for an SHS, 20 to 30% can afford a SHS with short or medium term credit, and another 25% could afford an SHS with long term credit or leasing.

Utility-scale solar energy environmental considerations include land disturbance/land use impacts, visual impacts, impacts associated with hazardous materials, and potential impacts on water and other resources, depending on the solar technology employed.

Solar power plants reduce the environmental impacts of combustion used in fossil fuel power generation such as green house gas and other air pollution emissions. However, concerns have been raised over land disturbance, visual impacts, and the use of potentially hazardous materials in some systems. These and other concerns associated with solar energy development are discussed below, and will be addressed in the Solar Energy Development Programmatic EIS.

·         Land Disturbance/Land Use Impacts

All utility-scale solar energy facilities require relatively large areas for solar radiation collection when used to generate electricity at a commercial scale, and the large arrays of solar collectors may interfere with natural sunlight, rainfall, and drainage, which could have a variety of effects on plants and animals. Solar arrays may also create avian perching opportunities that could affect both bird and prey populations. Land disturbance could also affect archeological resources. Solar facilities may interfere with existing land uses, such as grazing. Proper siting decisions can help to avoid land disturbance and land use impacts.

·         Visual Impacts

Because they are generally large facilities with numerous highly geometric and sometimes highly reflective surfaces, solar energy facilities may create visual impacts; however, being visible is not necessarily the same as being intrusive. Aesthetic issues are by their nature highly subjective. Proper siting decisions can help to avoid aesthetic impacts to the landscape.

·         Hazardous Materials

Photovoltaic panels may contain hazardous materials, and although they are sealed under normal operating conditions, there is the potential for environmental contamination if they were damaged or improperly disposed upon decommissioning. Concentrating solar power systems may employ liquids such as oils or molten salts that may be hazardous and present spill risks. In addition, various fluids are commonly used in most industrial facilities, such as hydraulic fluids, coolants, and lubricants. These fluids may in some cases be hazardous, and present a spill-related risk. Proper planning and good maintenance practices can be used to minimize impacts from hazardous materials.

·         Impacts to Water Resources

Parabolic trough and central tower systems typically use conventional steam plants to generate electricity, which commonly consume water for cooling. In arid settings, the increased water demand could strain available water resources. If the cooling water was contaminated through an accident, pollution of water resources could occur, although the risk would be minimized by good operating practices.

·         Other Concerns

Concentrating Solar Power (CSP) systems could potentially cause interference with aircraft operations if reflected light beams become misdirected into aircraft pathways. Operation of solar energy facilities and especially concentrating solar power facilities involves high temperatures that may pose an environmental or safety risk. Like all electrical generating facilities, solar facilities produce electric and magnetic fields. Construction and decommissioning of utility-scale solar energy facilities would involve a variety of possible impacts normally encountered in construction/decommissioning of large-scale industrial facilities. If new electric transmission lines or related facilities were needed to service a new solar energy development, construction, operation, and decommissioning of the transmission facilities could also cause a variety of environmental impacts.

Cost of Component & Conclusion

Cost of Components

Table 08: The electrical component cost for the generation of Inverter Circuit.

Name of Equipment

Unit Cost(TK)

Quantity

Cost (TK)

 

Resistors (1K, 10K , 100K, 47K, 22K, 150K  )

2.00

15

30.00

Diode 1N5408

2.00

11

22.00

Diode 1N4007

3.00

04

12.00

Transistor(NPN) BC 547

5.00

04

20.00

Capacitor 1µF 100v

3.00

02

6.00

Capacitor 1µF 50v

3.00

02

6.00

Capacitor10µF 50v

5.00

01

5.00

IC SG 3524

45.00

01

45.00

 IC LM358

10.00

01

10.00

MOSFET

5.00

02

10.00

PCB Board

1.00

Per inch

10.00

Hit Sink

8.00

Per inch

40.00

Relay D.C (12v)

22.00

01

22.00

Zener diode 5.1v

3.00

01

3.00

Variable resistor 10K

2.00

03

6.00

LED

5.00

02

10.00

Wire

15.00

1 meter

15.00

Panel board

1300.00

01

1300.00

Battery

1400.00

01

1400.00

Soldering Iron

130.00

01

130.00

Total cost=       3102

 Protection System:

We have taken some protections in this ckt. Such as:

               Back e.m.f protection:

  1. To protect from the back e.m.f that we connect across the rectifier diode of the relay.
  2. We used a rectifier diode across Battery Input port for protect the ckt. From back e.m.f of load.

            Temperature protection:

  1. To reduce the temperature of the MOSFET we used hit sink.

Over charge protection:

  1. To Protect over charging of the battery we used relay.

Conclusion

The main source of electricity generation in Bangladesh is the natural gas (about 82.69%, in the fiscal year 2008-09 its value was 4542MW). Natural gas produce the heat require driving the turbine which produces electricity. The reserve of natural gas is reducing day by day. To reduce the consumption of natural gas, Government has closed the production of some industry due to inadequate electricity supply (Ghorasal fertilizer, polash fertilizer etc). But the reserve of natural gas is now inadequate, an alternative should be employed. Solar energy is a very good option.

Bangladesh is a country with enough solar radiation to provide potential for sustaining SHS. From this radiation using the current available technology full demand of electricity can be overcome. But both the PV system and thermal system is very costly. This cost is high to consumer so government should take steps to setup solar energy plant.

At present, the solar home systems are not costly competitive against conventional fossil fuel based grid interfaced power sources because of the initial capital cost. However, to fulfill the basic needs for the consumer and improvements in alternative energy technologies bear good potential for widespread uses of such systems.

The proposed system feasibility may be a costly issue in respect of Bangladesh. However, it is possible to overcome by introducing some incentives offered by the government and utility companies. It can also be implemented in commercial building, telecommunication sector and water pumping for irrigation.

The Government of the people’s republic of Bangladesh is trying to meet the national electricity demand through various ways including installing Solar system. PV Solar energy conversion is only renewable energy source currently in operation in our country.

Solar thermal system is currently popular technology for producing electricity in megawatt scale. At latest technology it is equivalent to nuclear plant (Mojave solar park – 220,000 megawatts per year) without the radioactive dangers or the giant cooling towers to clog up the skyline. It is costly but in 10 years the cost can be recovered. (It doesn’t require any fuel!). So government should think about it.

If we can produce solar cell in our country the PV system cost will become 60% of current cost. Some organization in private sector already started assembling of solar panel to produce electricity. But the Government should take more steps toward about the solar cell production inside the country.                                                                                                                                                                                                                                                                                                                                                                                                                                                

  • Bangladesh has got ample solar insulation throughout the country. Daily average solar radiation varies from 4 to 6.5 kWh/m2. Maximum amount of radiation is available on the month of March- April and minimum on December-January. There is bright prospect for applications of solar thermal and photovoltaic systems in the country.
  • All Non-renewable have emission which global warming and destruction to environment
  • All renewable energy need external source but solar absolutely independent.
  • Among all energy solar is less polluting
  • Among all energy solar is less costly
  • Of all the energy sources available, solar has perhaps the most promise.
  • Solar energy is free,
  • No one regulates sunlight, it’s already ours.
  • Recycle , recharge, reuse battery
  • Campaign for green energy
  • Campaign for waste disaster
  • At present has no concentrating panel system so initiatives to be taken to install concentrating solar thermal generating system.

Categories
Business Mathematic

Role of Business Mathematics

Introduction:

The role of mathematics in Business decisions has very important in the process of managerial decision models and algorithms. To turn to the specific aspects of the quantitative decision making process, it is possible to recognize three distinct phases in every decision situation. First is carefully defined the problem, second is a conceptual model to be generated and third is the selection of the appropriate quantitative model they may lead to a solution. Lastly a specific algorithm is selected. Algorithms are the orderly delineated sequences of mathematical operations that lead to a solution. The algorithms generate the decision which is subsequently implemented managerial action program. The entire process is shown below:

Defined problem ——> Conceptual model —> Quantitative Model —-> Algorithms—-> Decision —- Action programs.

You are not being ripped off? You need to use math to calculate compound interest rates (to see how much your savings can grow). You also need to use math to understand the monthly percentages, which are added to your credit cards or bank loans, or you could end up paying Rs10,000 in 5 year’s time for borrowing Rs2,000 today! This is a good reason to understand mathematics

Criticism on mathematics

Mathematics is not a closed intellectual system, in which everything has already been worked out. There is no shortage of open problems. Mathematicians publish many thousands of papers embodying new discoveries in mathematics every month.

Mathematics is not numerology, nor is it accountancy; nor is it restricted to arithmetic. Pseudo mathematics is a form of mathematics-like activity undertaken outside academia, and occasionally by mathematicians themselves. It often consists of determined attacks on famous questions, consisting of proof-attempts made in an isolated way (that is, long papers not supported by previously published theory). The relationship to generally accepted mathematics is similar to that between pseudoscience and real science. The misconceptions involved are normally based on misunderstanding of the implications of mathematical rigor; attempts to circumvent the usual criteria for publication of mathematical papers in a learned journal after peer review, often in the belief that the journal is biased against the author; lack of familiarity with, and therefore underestimation of, the existing literature. The case of Kurt Heegner’s work shows that the mathematical establishment is
neither infallible, nor unwilling to admit error in assessing ‘amateur’ work. And like astronomy, mathematics owes much to amateur contributors such as Fermat and Mersenne. ‘Modern mathematics’ is indeed boring and devoid of meaning in most papers. That’s why I stick to reading the works of the greats like von Neumann, Wiener, Einstein, and hosts of others. What made them great? They explain things, and then go on to carry out tremendously complicated calculations. I think the advent of calculators and numerical methods has hurt the advance and
understanding of math to a large degree. However, on the flip side, new symbolic methods allow computations, which are a great, help and lead to new relations not previously seen, so maybe there is hope yet. But, apart from that fact, I wouldn’t say modern mathematics is particularly boring. In fact, I think it’s the second most exciting thing in the universe! The first is, of course, the mathematics of the future. The problem is just that most writers of mathematics succeed, against all odds, at making the subject seem boring. They’ve developed a lot of methods for
doing this. One is to make the results hard to understand.

Another is to not provide enough contexts for people to see why the results are interesting. A third is to write in a style that has all the drama and flair of overcooked porridge.

Role of mathematics in business:

 

Mathematics is used in most aspects of daily life. Many of the top jobs such as business consultants, computer consultants, airline pilots, company directors and a host of others require a solid understanding of basic mathematics, and in some cases require a quite detailed knowledge of mathematics. It also play important role in business, like Business mathematics by commercial enterprises to record and manage business
operations. Mathematics typically used in commerce includes elementary arithmetic, such as fractions, decimals, and percentages, elementary algebra, statistics and probability. Business management can be made more effective in some cases by use of more advanced mathematics such as calculus, matrix algebra and linear programming.

Commercial organizations use mathematics in accounting, inventory management, marketing, sales forecasting, and financial analysis.

In academia, “Business Mathematics” includes mathematics courses taken at an undergraduate level by business students. These courses are slightly less difficult and do not always go into the same depth as other mathematics courses for people majoring in mathematics or science fields. The two most common math courses taken in this form are Business Calculus and Business Statistics. Examples used for problems in these courses are usually real-life problems from the business world.An example of the differences in coursework from a business mathematics course and a regular mathematics course would be calculus. In a regular calculus course, students would study trigonometric functions. Business calculus would not study trigonometric functions because it would be time- consuming and useless to most business students, except perhaps economics majors. Economics majors who plan to continue economics in graduate school are strongly encouraged to take regular calculus instead of business calculus, as well as linear algebra and other advanced math courses.

Other subjects typically covered in a business mathematics Curriculum include:

Matrix

Algebra
Linear  programming
Probability theory

Another meaning of business mathematics, sometimes called commercial math or consumer math, is a group of practical subjects used in commerce and everyday life. In schools, these subjects are often taught to students who are not planning a university education. In the United States, they are typically offered in high schools and in schools that grant associate’s degrees.

A U.S. business math course might include a review of elementary arithmetic, including fractions, decimals, and percentages. Elementary algebra is often included as well, in the context of solving practical business problems. The practical applications typically include checking accounts, price discounts, markups and markdowns, payroll calculations, simple and compound interest, consumer and business credit, and mortgages. The emphasis in these courses is on computational skills and their practical application, with practical application predominating. For example, while computational formulas are covered in the material on interest and mortgages, the use of prepared tables based on those formulas is also presented and emphasized. Mathematics can provide powerful support for business decisions. In their later business careers, this will motivate them to consult with mathematicians and employ effective quantitative methods.

Mathematics provides many important tools for economics and other business fields. However, our discipline does not profit from this work when students (who later become part of the general public) are unaware of its existence. Presenting trivial mathematical applications only makes matters worse, since they are clearly recognizable as being of little importance. This actually diminishes our subject in the eyes of students. Using computers to bring the underlying structure of significant mathematics to undergraduates allows them to appreciate the role that our Subject can play in their academic work and later lives. The recognition of its importance by many students each year will certainly strengthen the position of mathematics in our society. Why do business consultants and directors need to know math?” you may ask. Business is all about selling a product or service to make money. All transactions within a business have to be perfectly measure through the mathematics terms.

Role of Business Mathematics