Generation of Electricity Through Solar Cell

8/6/2019 Generation of Electricity Through Solar Cell

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Generation Of Electricity through Solar cell and Thermocouples with selling power back to Grid

Abdullah Ansari, Azam Rafique, Arsalan Bhatti 1Student, Department of Electronics & Biomedical Engineering, Mehran University of Engineering and Technology,

Jamshoro [email protected]

Abstract This Project explains ways to generate ElectricPower by using two different Solid State devices, theircomparison and selling the power thus generated back toGrids. The methods defined below include Generation of Green Energy from Solar cell and by thermocouples (throughsunlight or any kind of heat source) and net metering conceptof selling e lectricity.

Keywords- Solar cell; Themocouples; Green Energry, net metering, heat

I. INTRODUCTIONGeneration of Electricity involves Processing that

converts a form of energy into electrical energy. It means weneed more and more natural resources to generate electricityin the time when energy crises are increasing with thepassage of time. Electricity is being generated from VariousWays such as Water (Hydral), Solar, Thermal, NuclearSources etc.

Among the above defined sources of energy, most of theresources except Sunlight and Heat have limitations. Solarcells Generate cheap and green electricity from sunlight.Solar electricity systems capture the sun's energy usingphotovoltaic (PV) cells. The cells convert the sunlight into

electricity, which can be used to run household appliancesand lighting. Solar energy makes much sense for Pakistanfor several reasons: firstly, 70% of the population lives in50,000 villages that are very far away from the national grid,according to a report by the Solar Energy Research Center(SERC). [10]

While Thermocouples uses thermal energy to generatevoltages. It basically involve two metals with differentthermal co-efficient so that if one becomes source (forproviding free electrons), other acts as sink.

More over we cant only generate our own power but tosell it to power producing companies with the concept of netmetering. [5]

Hence in a Country where Power Crises are one of thegigantic problems, this project may be revolutionary in twosenses. One to generate ones own electricity and secondmore interesting is to sell the power back to stations so thatsome one other can utilize it and you decrease the amount of electricity bills.

II. ELECTRICITY GENERATION METHODS VIA SOLARCELLS AND THERMOCOUPLES

A. Solar Cell(Method 1):The mentioned techniques for generating electricity have

their own strengths and weaknesses. Two popularapproaches using two sensors have been discussed. One of them is Photo-Voltaic method. As the name implies, Photo-Voltaic method involve conversion of light energy into directvoltage. Photons present in the sunlight when strikes thesurface of Photovoltaic (solar) cell, extracts electrons out of it which flows freely into the medium (wire). [3]

Figure 1. Method of Generating Electricity from Solar Cell

Figure 1 explains the phenomenon of generating electriccurrent from Solar Energy. One must note that the currentthus obtained is DC and it has to be converted into AC inorder to turn AC devices on. More over a single solar cellcannot produce more than few volts of Electricity; we use

solar panels that contain series of solar cells to generate ameaningful amount of energy with the efficiency of 17percent. [2]


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B. Thermocouples/Thermopiles(METHOD 2):

The combination of two different types of metals asshown in figure 2 with a joint junction that senses thetemperature changes between the metal plates and generatethe voltage difference accordingly. In order to generate auseful amount of voltage, we need Thermo-ElectricGenerators (TEGS).

Figure 2. Construction of Thermocouples

TEGs are made from thermoelectric modules which aresolid-state integrated circuits that employ three establishedthermoelectric effects known as the Peltier, Seebeck and

Thomson effects. It is the Seebeck effect that is responsiblefor electrical power generation. Their construction consistsof pairs of p-type and n-type semiconductor materialsforming a thermocouple. These thermocouples are thenconnected electrically forming an array of multiplethermocouples (thermopile). They are then sandwichedbetween two thin ceramic wafers, as shown in Figure 3 [2]

Figure 3. Series of thermocouples

These thermocouples are then connected electrically inseries and/or parallel forming an array of multiplethermocouples (thermopile). When heat and cold are appliedthis device then generates electricity. Almost any heat sourcecan be used to generate electricity, such as solar heat, oceanheat, geothermal heat, even body heat! In addition the

efficiency of any device or machine that generates heat as aby-product can be drastically improved by recovering theenergy lost as heat.

III. SELLING POWER TO GRID STATIONS

This might be an interesting and cumbersome process butcan bring huge changes in systems of our country. Thisprocess is called Feed-in-Tariffs (FITs). [5]

To make this system work in Pakistan, we need tounderstand the concepts of Smart grids and Net-metering.

A smart grid is a form of electricity network utilizingdigital technology. It comes with an information and netmetering system, which includes smart meters, as shown inFigure 4. [4]

Figure 4. Smart Grid Network

Net metering is the simplest way to setup a grid-tiesystem. In such a system you only have one utility kWhmeter and it is allowed to spin in either direction dependingon if you are buying or selling energy. In a non net-meteredsystem, the utility company will require that you install asecond kWh meter to record any excess energy that you sellback to them, as shown in Figure 5.[6]

Figure 5. Selling Power to Grids

The concept of net-metering can be visualized from Figure6.


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Figure 6. System to sell Power to Grid

IV. PROJECT OBJECTIVES To design a prototype based on the generating cheap

and useful electricity through different ways for

individual use. To utilize maximum amount of heat wasted in

factories and industries.

To aware the entrepreneurs to use maximum of theseunlimited energy source like sunlight.

To make most of the persons in my country to havetheir own small power stations for homes andoffices.

To have Collective bargaining between PowerSupply companies and Consumers (As both sittogether and set the prices per unit in a two wayprocess).

V. SIGNIFICANCE OF PROJECT Our project is to find out different ways of generating

electricity and selling it to grids in order to remove a riftbetween consumers and Electric supply companies.

One significant advantage of this application is that thesystem helps users to have their own electricity generationstores and hence have no worries for electricity bills andload-shading.

VI. EQUIPMENTS AND THEIR FUNCTIONS

A. For Solar Electricity:In order to generate electricity directly from sunlight we

need following equipments:

1) Photo-Voltaic sensor (Solar cell):A solar cell is a semi-conductor (Solid State) device that

converts the energy of sunlight directly into electricity by the

photovoltaic effect. Assemblies of cells are used to makesolar modules, also known as solar panels, as shown inFigure 7.

Photovoltaic is the field of technology and researchrelated to the practical application of photovoltaic cells inproducing electricity from light, though it is often usedspecifically to refer to the generation of electricity fromsunlight. [1]

Figure 7. A solar cell panel made from a monocrystalline silicon wafer

2) Inverter An inverter is an electrical device that converts direct

current (DC) to alternating one (AC); the converted AC canbe at any required voltage and frequency with the use of appropriate transformers, switching, and control circuits.

Static inverters have no moving parts and are used in awide range of applications, from small switching powersupplies in computers, to large electric utility high-voltagedirect current applications that transport bulk power.Inverters are commonly used to supply AC power from DCsources such as solar panels or batteries. [4]

Figure 8. An Inverter

Inverter designed to provide 115 VAC from the 12 VDC

source provided in an automobile. The unit shown in Figure6 provides up to 1.2 amperes of alternating current, orenough to power two sixty watt light bulbs. [4]

3. Leads or wires to send the power to destination

4. Battery to store the power


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B. For Electricity From Thermocouples:Electricity from thermocouple can be generated by thesimilar mechanism; the components required for generatingelectricity are shown below:

Thermocouples Leads or wires Heat sink Inverter

VII. RESULTS AND COMPARISON One 165 watt Sharp PV panel produces 0.6 kWh

of electricity per day. One 25 watt TEG alsoproduces 0.6 kWh of electricity per day (with acontinuous heat source) day or night. [2]

The costs of solar and thermoelectric generatorsbased on the amount of electricity they actuallyproduce per day, tells that TEGs cost far less perkWh than solar! The PV (photovoltaic)equivalent of 50 watt TEG operating on a woodstove is 330 watt or 1.2 kWh per day. Thismeans using just 3 of 50 watt TEGs can producethe same amount of electricity in a day as 990watts of solar PV panels. If comparing costs, theprice range for 990 watts of solar would be$2,500 to $5,000 depending on the particularbrand. Whereas the cost for 3 of 50 watt TEGscan range from $750 to about $1100 dependingon the volume purchased. [2]

Unlike solar TEGs is not dependant on the sunto producing electric power. If you have a heatsource they can produce power 24/7-365!Granted you will need a cheap or free source of heat, but if you already have an existing heatsource such as a wood stove or hot flu gases

there is no added fuel cost to run the TEG!Unlike conventional electric generators poweredby fossil fuels. [2]

TEGs have no moving parts to break ormaintenance to perform, (with the exception of maintaining coolant level and changing thecirculating pump every 2 to 3 years on watercooled models). They are virtually silent andrated to last more than 200,000 hours of continuous operation! [2]

VIII. IMPLEMENTATION IN PAKISTAN

A. Solar Cell: Solar Panels have been used in several areas of

Pakistan to Generate Electricity.

The areas are Thar dessert, Villages near Thattaand Rawalpindi.[8]

Project for Community Solar Dryer for Drying

Dates started at Jun 2005 and completed inMarch 2008 worth Rs 10.656 bill [10]

Development of Low Power High IntensitySolar Lights

Projects have started by NGOs Providing solarElectricity to Flood and Earthquake affectedareas[7]

B. Thermocouples: Used as Power Generators In NASA but not in

Pakistan.

Thermocouple was used to drive the radio byProf Masood Anwar of Gordon College

Pakistan, the heat source was Hookah.[9]

ACKNOWLEDGEMENT We gratefully acknowledge the supervisor of our project

Sir Ghulam Mustafa and Madam Attiya Baqai for their kindhelp and giving us a start to write this research paper.

It is all due to Allahs blessings and ContinuousSuggestions by our supervisor that we have completed ourfirst research paper.

REFERENCES [1] http://www.google.com/ [2] http://www.TEGpower.com/ [3] www.youtube.com/Solar electricity [4] www.wikipedia.org [5] http://www.sellmyelectricity.co.uk/ [6] http://www.mywindpowersystem.com/2009/09/selling-electricity-

back-to-the-grid-selling-power-back-to-the-grid-selling-energy-back-to-the-grid

[7] http://pakistaniat.com/2009/02/17/utilizing-solar-energy-in-pakistan/ [8] http://www.siemens.com.pk/solarpower.html [9] Masood Anwar, Popular Science" Magazine, P#156 Nov 1960[10] http://www.riazhaq.com/2009/02/solar-energy-for-sunny-

pakistan.html


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Generation of Electricity Through Solar Cell