Renewvable Sources Seminar Report 6l3h4s

1.Abstract:Wind, Solar, Geothermal, bio-energy, ocean are the “New Renewable” for electric power generation. These are widely promoted by governments and others to help avoid greenhouse gas emissions that contribute to to global climate change. Development in the field of un conventional Energy sources is required for optimum Utilization of these new renewable and for producing more and more electricity. World wide more than 1.6 billion people do not have access to electricity (1) of which 80% live in isolated locations, hilly regions and remote villages which remain un-reached by modern energy services, electrification program and electricity grids so developments are in Non-conventional energy sources such as solar energy and wind energy are needed to supply electricity or their all round development . In addition, renewable energy is ed by many different groups for a wide range of reasons, including : providing power to areas not served. or poorly served, by an electric power grid, achieving grid independence: providing distributed power for smaller Applications ; reducing vulnerability to fuel price fluctuations; reducing emissions of air pollutants and innovations.

2.INTRODUCTION:The Industrial Revolution of the 19th century ushered in new technologies. The spurt in inventions in that century was unprecedented in many ways some of these inventions involved use of natural resources like coal and oil. The thought of exhaustible nature of these resources and the environmental damage from the use of these resources never occurred either to the inventors or the subsequent generations. In the Quest to sustain galloping economic activity, The dependence on coal and oil has soared at a phenomenal rate over the years. The conventional energy sources result in the release of carbondioxide and other gases in to the atmosphere caie environmental damage. It has become imperative to look at energy technology with a new perceptive. There are abundant renewable sources of energy such as wind, sun, water, sea, biomass apart from even daily wastes. These sources are pollution free and hence clean energy apart from being unlimited/Inexhaustible. The demand for power is growing rapidly. The problem will be compounded due to fast depletion of fossil fuel deposits, quality of fuels, heavy price to be paid for basic materials plus their transportation cost and environmental degradation caused by the use of conventional energy sources under such conditions, environment friendly and pollution free non-conventional and renewable energy sources known as ‘clean and green energy’ have emerged as an important alternatives to conventional energy sources. The renewable energy source are clean and inexhaustible. As they rely on sun, wind biomass etc, as primary source of energy. The country is endowed with large amounts of sustainable resources base and non conventional energy technologies which are well suited for grid connected power generation, energy supplies in remote areas Which are not/ could not be connected to the grid and for captive consumption. Non-conventional energy sources like wind energy, solar energy through thermal as well as photovoltaic system, biomes and hybrid sources will heap to a great extent in enhancing power generation capacity. Hence appropriate

policies and

programs that optimize the use of available energy resources with new technologies have to be propagated, promoted and adopted.

3.Renewable Resource Strength Hypothetically there is enough wind and solar energy on earth to meet current and projected energy needs for many years. Unlike petroleum, solar and wind resources are more widely distributed around the world. This is an advantage in term of energy security, but a challenge for every conversion because huge land or sea areas may be required to collect enough energy for typical load centers. This section summarizes recent rends in unconventional energy sources.

3.1Solar Energy : 1) Solar energy is the most readily available and free source of energy since prehistoric times. India receives solar energy in the region of 5 to 7 Kwh/m2 for 300 to 330 days in a year. This energy is sufficient to set up 20 MW solar power plant per sequel kilometer land area solar energy can be utilized directly by two technologies ; namely solar thermal and solar photovoltaic. (Solar electric)

a) Solar Photovoltaic : Solar Photovoltaic technology is considered as potential alternative for low energy demand that allows an electricity infrastructure comprising of network of local grid cluster with distributed electricity generation. We can have individual SPV system for every household or centralized SPV plant to meet combined load demand of whole village. Solar PV power is ideally suited for telecommunication applications such as, local telephone exchange, radio and TV broadcasting, microwave and other form of communication links in remote and hilly terrain where grid power is not feasible. Solar lantern, mobile phone, portable SPV powered mobile refrigerator. SPV powered water pumping system are most important and extensive application stand alone solar PV system.

PV tracking systems is an alternative to the fixed, stationary PV s. PV tracking systems are mounted and provided with tracking mechanism to follow the sun as it moves through the sky. These tracking systems run entirely on their own power and can increase output by 40%. Photovoltaic Technology is in a state of rapid development. Most of the recent development have been aimed at improving the manufacturing process, extending the serviceable lifetime, and particularly on reducing costs, especially capital costs.

b)Solar Thermal Technology : Harnessing solar energy for cooking purpose is an attractive and relevant option. A variety of solar cookers have been developed, which can be clubbed in four types of basic designs.

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Box types solar cooker.

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Dish type (Parabolic) solar cooker.

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Advance solar cooker.

Use of solar energy for fresh water through distillation has been demonstrated in several moderate sized pilot plants called solar still. Some features of solar energy make its utilization attractive for irrigation water pumping. Which are solar pumping system it consist of pump driven by motor run by solar electricity in stead of conventional electricity. Never concepts for solar thermal power include new hybrids for example, a solar thermal plant can be combined with natural gas, sharing a large portion of the balance of plants. Solar can also be combined with energy storage to take advantage of peak grid prices.

3.2 Wind Energy Resources :Wind power today contributes about 0.3% of total electric power generation worldwide, and is growing rapidly like hydropower, biomass and geothermal energy, wind power can be competitive with conventional power generation in places where the resources and / or policies are favorable. Utilization of wind resources is limited by the availability of areas with good resources near suitable transmission infrastructures, and to a lesser extent by costs.

a)

Recent wind energy technology : The basic wind energy conversion device is the wind turbine although various designs and configurations exist. These turbines are generally grouped two types. 1) Vertical axis wind turbines, in which the axis of rotation is vertical with respect to ground (and roughly perpendicular to the wind stream) 2) Horizontal axis wind turbines, in which the axis of rotation is horizontal with respect to ground land roughly parallel to wind stream.

b)

Wind Electric Generators (WEG) : Wind electric generator converts kinetic energy available in wind to electrical energy

by using rotor, gear box and generator. At present, WEG,s of rating ranging from 225 KW to 1000 KW

(3)

are being installed in our country recent developments have focused on

increasing size 3 MW and larger (3) the improvements have been aimed at reducing noise and potential for interference with radar and at reducing death of birds. In order to capture low speed wind resources, other efforts have been focused on cost reduction and overall efficiency improvement. There has also been some development of vertical axis wind turbines for smaller applications. Wind has it converts the energy from a chemical reaction directly into electricity and heat. But unlike a battery, which is limited to the stored chemicals within, a fuel cell has the capability of generating energy as long as fuel is supplied. Currently produced fuel cells combine hydrogen and oxygen without combustion to produce electricity. The oxygen comes from the air, while the hydrogen can either be produced from water (using electricity) or extracted from fossil fuels. New fuel cells are being developed that can use fossil fuels directly. Fuel cell technology has been around for over 150 years and it shows great promise in powering vehicles and in providing energy for residential applications

3.3 Biofuels:Plants use photosynthesis to grow and produce biomass also known as biomatter, biomass can be converted directly into liquid fuels - biofuels - for our transportations needs (cars, trucks, buses, air planes and trains). The two most common types of biofuel are ethanol and biodiesel. a) Ethanol is an alcohol, similar to that used in beer and wine. It is made by fermenting any biomass high in carbohydrates (starch, sugar or celluloses) through a process similar to brewing beer. Ethanol is mostly used as a fuel additive to cut down a vehicles carbon monoxide and other smog causing emissions. Flexible - Fuel vehicles, which run on mixtures of gasoline and upto 85% Ethanol are now available. b) Biodisel produced by plants such as rapeseed (canola), sunflowers and soyabeans, can be extracted and refined into fuel, which can be burned in diesel engines and buses. Biodiesel can also made by combining alcohol with vegetable oil, or recycled cooking greases. It can be used as an additive to reduce vehicle emissions (typically 20%) or in its pure form as a renewable alternative fuel for diesel engine.

3.4 Ocean Energy:Oceans cover more than 70% of earths surface, making them the worlds largest solar Collector. The sun warms the water a lot more than the deep ocean water, and this temperature difference stores the thermal energy. The ocean consists of two types of energy : Thermal energy from the suns heat and mechanical energy from the tides and waves. Ocean thermal energy is used for many applications, including electricity generation. There are three types of electricity conversion systems : closed cycle, open cycle, and hybrid. Closed cycle se the oceans warm surface water to vaporizes a working fluid, which has a low boiling point, such as ammonia. The vapour expands and turn a turbine. A turbine then activities a generator to produce electricity. Open cycle systems actually boil the seawater by operating at low pressures. This produces steam that es through a turbine / generator . The hybrid system combine both closed cycle and open cycle systems.

Tapered Channel Wave Power:-

These shoreline systems consist of a tapered channel which feeds into a reservoir constructed on a cliff. The narrowing of the channel causes the waves to increase their amplitude (wave height) as they move towards the cliff face which eventually spills over the walls of the channel and into the reservoir which is positioned several meters above mean sea level. The kinetic energy of the moving wave is converted into potential energy as the water is stored in the reservoir. The water then es through hydroelectric turbines on the way back to sea level thus generating electricity

Advantages:-No pollution -Renewable resource -More efficient than wind because of the density of water -Predictable source of energy vs. wind and solar -Second generation has very few disadvantages -Does not affect wildlife -Does not affect silt deposits -Less costly – both in building and maintenance

Disadvantages:-Presently costly -Expensive to build and maintain -A 1085MW facility could cost as much as 1.2 billion dollars to construct and run -Connection to the grid -Technology is not fully developed -Barrage style only produces energy for about 10 hours out of the day -Barrage style has environmental affects -Such as fish and plant migration -Silt deposits -Local tides change- affects still under study

3.5 Other Sources:a) Geo thermal energy : Geo thermal energy is a renewable heat energy from underneath the earth. Heat is brought to neat surface by thermal conditions and by intrusion into the earths crust. It can be utilized for power generation and direct neat application. Potential sites for geo thermal power generation have been identified mainly in central and north regions of the country. Suitable technologies are under development to make its exploitation viable. Geothermal electric capacity in the United States is over 3,000 MW. Geothermal power plants use high temperatures deep underground to produce steam, which then powers turbines that produce electricity. Geothermal power plants can draw from underground reservoirs of hot water or can heat water by pumping it into hot, dry rock been the fastest growing energy source in the U.S. over the last decade mainly due to very significant improvements in wind energy technology. The American Wind Energy Association predicts that 6,000 MW of windpower will be installed by the end of 2004. This is enough to power 1.5 million homes. Wind power is produced by the energy of the wind turning aerodynamic blades mounted to a hub. The hub is connected to a shaft that turns a generator. Large utility-scale wind turbines range in size from 50 kilowatts to over four megawatts. Smaller wind towers (under 50 kW) are suitable for residential and agricultural use. Geothermal Heat Pumps:Using the heat from the earth is a very efficient and renewable method of heating and cooling your home. Geothermal heat pumps (Chapter 5) use the stable temperature of the ground around your home as a source of heat in the winter and cooling in the summer. These systems move heat between the home and ground instead of creating heat by burning fuel and consequently they operate very cleanly and are usually at least three times more efficient than other systems on the market – including those that are energy efficient themselves. A complete geothermal system can also have the ability to provide hot water through a “desuperheater”. A geothermal heat pump system including installation, duct system and hot water delivery can range in cost from $14,000 to $20,000 but will save significant money over the long term due to increased efficiency.

Use heat to make steam to turn turbine for electrical generation Note: deep hot waters are corrosive to best to inject clean water in a closed system and bring it back to the surface as steam

Advantages-Renewable -Easy to exploit in some cases -CO2 production less than with fossil fuels -High net energy yield

Disadvantages-Not available everywhere -H2S pollution -Produces some water pollution (somewhat similar to mining)

b)Hydrogen and fuel cells : In both hydrogen and fuel cells electricity is produce through an electro chemical reaction between hydrogen and oxygen gases. The fuel cells efficient, compact and reliable for automotive applications. Hydrogen gas is the primary fuel for fuel cells also. Hydrogen can be produced from electrolysis of water using solar energy. It can also be extracted from sewage gas, natural gas, naptha or biogas. Fuel cells can be very widely used once they become commercially viable .

Hydrogen Production:•

Electrolysis –

Efficiencies 70-85%

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Produces highest purity of hydrogen

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Currently, the electricity consumed is usually worth more than the hydrogen produced

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Experimental methods –

Biological hydrogen production

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Direct photolysis

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Thermolysis

c) Biomass co-generation : Co-generation improves viability and profitability of sugar industries. Indian sugar mills are rapidly turning to bagasse, the leftover of cane after it is crushed and its juice extracted, to generate electricity. This is mainly being and earn additional revenue. According to current estimates, about 3500 MW of power can be generated from bagasse in the existing 430 sugar mills in the country. Around 270 MW of power has already been commissioned and more is under construction.

d) Biogas Digester : Biogas Digester uses the process of anerobic digestion. An organic feed stock, such as clop residues, or food or animals waste, is put into the air tight container. Bacteria then break down the waste releasing biogas. This gas consisting mostly of methane can be siphoned off for small scale electricity generation using a gas fired combustion turbine. The process also produce slurry as a by product which makes high quality fertilizer.

4.Conclusions Each of the “New renewables” will gain market share in the coming decades. Their growth today is driven by policy. To a large extent, Renewable policies are surrogates for climate policy. Renewable energy policies will be necessary to the growth of market share for new renewables until reductions in renewable energy costs from technological innovations, and increase in prices of instruments responsible for greenhouse gas emissions, are sufficient to close the gap between conventional and new renewable energy.

5.References 1) INTERNATION ENERGY AGENCY, “World Energy Outlook 2009” 2) www.irda.com 3) www.winenergy.com 4) Renewables global status report 2009 (PDF) 5) Wikipedia 6) www.google.com