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Renewable Energy-Resources & Utilization

BY

Ravi.N.Kumar , GM , NDPL

Synopsis : Looking toward Global Warming ; increasing pollution ; continuously increasing powerdemand on account counties economy & development , and depleting existing energy sources , it

has been felt necessary to switch over to Renewable energy sources to meet the urgencies and to

support existing power sector demand and supply. Renewable energy resources has been

discussed in this article. Induction of these resources not only will cover up demand & supply of power

but also will support in reducing pollution level, hence the global warming. Various renewal energies

 / sources have been covered in this article for awareness of promising engineers.

Introduction : Conventional energy production methods have always contributed to environmental

pollution and have also led to the rapid destruction of the planet‘s natural resources. The gradual

depletion of the naturally available resources, such as coal and petroleum products, is another major

cause for concern. These resources are either limited in supply or will be exhausted in a matter oftime. They can only meet our energy demands for another fifty to seventy years. So in an effort to find

alternative forms of energy, the world has turned to renewable energy sources as the solution.

Renewable energy are derived from natural resources / processes that are replenished constantly.

These natural resources consist of Solar, Hydro, Wind, Geothermal, Ocean and Biomass. The most

common advantage of each is that they are renewable and cannot be depleted.

These sources has unique characteristics which influence how and where they are used

The majority of renewable energy technologies are powered by the sun. The Earth-

Atmosphere system is in equilibrium such that heat radiation into space is equal to incoming solar

radiation . The hydrosphere (water) absorbs a major fraction of the incoming radiation. Most radiation

is absorbed at low latitudes around the equator, but this energy is dissipated around the globe in the

form of winds and ocean currents. Wave motion may play a role in the process of transferring

mechanical energy between the atmosphere and the ocean through wind stress.

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Main Sources of renewable energy

2008 worldwide renewable-energy sources. 

If you look into , the disadvantages of renewable energy are quite less than the advantages;

Advantages- 

They are a clean energy, as they don‘t pollute the air. 

They don‘t contribute to global warming or greenhouse effects.

Since their sources are natural the cost of operations is reduced .

They also require less maintenance on their plants.

Disadvantage-  

It is difficult to produce the large quantities of electricity their counterpart the fossil fuels are

able to. Since they are also new technologies, at present the cost of initiating them is high.

The power obtained from renewable energy sources like the sun, wind, water, plants, andEarth's internal heat also called "green power." Buying green power from the utility is one of theeasiest ways to use renewable energy without having to invest in equipment or take on extramaintenance.

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Hydro Energy  – 

Hydro power is produced by harnessing vast waters such as streams, the rising and falling of tidesdue to lunar and solar gravitation, wave energy and the energy of sea currents.

Due to the high density of water, about 800 times the density of air a slow flowing stream of water, or

moderate sea swell, can yield considerable amounts of energy.

Forms of hydro energy: 

Hydroelectric energy is one of many energy sources used in the world.There are many forms of hydroenergy:

Waterwheels: These have been used for centuries to power mills and machinery.

Hydro Electric energy is a term usually reserved for large-scale hydroelectric dams. e.gBhakra Dam on River Sutlej ; Pong Dams on Beas river & Dehar Dam on Beas-Sutlej link.

In Asia ,

The highest concrete dam is Bhakra dam in India The Longest concrete dam is Hirakund dam in India The longest earthen dam is Pong dam in India

The largest hydroelectric dam in the world is Rogun in Tajikistan.

  Small /Minni hydro systems are hydroelectric power installations that typically produce up to25 MW of power. Mostly are installed on running water channel.

  Micro hydro systems are hydroelectric power installations that typically produce up to 100 kWof power.

  Damless hydro systems derive kinetic energy from rivers and oceans without using a dam.  Ocean energy describes all the technologies to harness energy from the ocean and the sea: 

o  Marine current power. Similar to tidal stream power, uses the kinetic energy of marinecurrents

o  Tidal power captures energy from the tides. Two different principles for generatingenergy from the tides are used at the moment:

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  Tidal motion in the vertical direction  — Tides come in, raise water levels in abasin, and tides roll out. Around low tide, the water in the basin is dischargedthrough a turbine, exploiting the stored potential energy. 

  Tidal motion in the horizontal direction  —Using tidal stream generators in a tidalstream. Due to the high density of water, tidal currents can have a lot of kineticenergy. 

o Wave power uses the energy in waves. Wave power machines usually take the form offloating or neutrally buoyant structures which move relative to one another or to a fixedpoint. Wave power has now reached commercialization.

  Vortex power is generated by placing obstacles in rivers in order to cause the formation ofvortices which can then be tapped for energy.

Scope of Hydro Power in India

India has been generating hydro-power for more than a century.

  As per CEA‗s studies, India ranks fifth in the world in terms of exploitable hydro

potential.  India‘s exploitable hydroelectric potential is estimated to be 150,000 MW, whereas the

installed capacity in the country has so far been 34,654 MW, (about 23 % of thepotential).

According to the Ministry of New and Renewable Energy (MNRE), the potential ofIndian small hydro power projects (up to 25 MW) is estimated at 15,000 MW, whereasthe country has so far set up SHP projects with a cumulative installed capacity of 1,976MW only.

The Government envisages a capacity addition of 1,400 MW during the 11th Five-YearPlan period (2007-2012). Apart from this, projects aggregating to a 394 MW capacityare under implementation.

The Indian Renewable Energy Development Agency (IREDA) arranges low-interest

loans for SHP power stations (capacities up to 25 MW). A few incentives; subsidies &including concessions, are available for SHP projects. Many states have announcedpreferential tariff structures for SHP projects.

The Government of India is encouraging the development of small hydro projects through public andprivate sector participation in various States.

How a hydro dam works: Water behind a dam flowsthrough the intake and then into a penstock or a pipe. This water then pushes against the blades of a

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turbine and makes it move with pressure. This turbine then moves and spins a generator in order toproduce electricity. This electricity is then sent over to grids.

Advantages- 

Hydropower is a large renewable source of energy.

The power source does not deplete natural resources. The cost of building a dam is high. Once it is in place the only cost is maintenance. Hydroelectric power is less expensive than electricity generated from fossil fuels or nuclear

energy. Once a dam is constructed, electricity can be produced at a constant rate. It has very low operating costs. It does not emit carbon dioxide or other harmful emissions ( Green House Gases )and so does

not contribute to pollution , hence global warming. If electricity is not needed, the sluice gates can be shut, stopping electricity generation. The

water can be saved for use another time when electricity demand is high. It can handleseasonal and high peak load demand.

Dams are designed to last many decades and so can contribute to the generation of electricityfor many years / decades.

The lake that forms behind the dam can be used for water sports and recreation.

The lake's water can be used for irrigation purposes.

Disadvantages 

Dams are extremely expensive to build and must be built to a very high standard. The high cost of dam construction means that they must operate for many decades to become

profitable. The flooding of large areas of land means that the natural environment is destroyed. The flooding of large areas of land cause habitats to change, thereby endangering local and

surrounding wildlife. But micro hydro can be used for small farms, homes or small businesses.

The impact of these plants is determined by the flow of the river. you rely on rain to fill the reservoirs . water may be directly released for irrigation and not always running through the dam. Power House is not usually centrally located, and require a lot of infrastructure & power lines

to take it to where it is needed . Though wave and tidal stream power schemes exist, they will need a lot of development

capital. Further, these dams produce large amounts of carbon dioxide and methane fromrotting vegetation.

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Solar energy- 

The ultimate source of much of the world's energy is the sun, which provides the earth with light, heatand radiation. Solar energy is our earth's primary source of renewable energy.

Solar power has great potential, but in 2008 supplied less than 0.02% of the world's total energysupply. To provide the continuous availability of energy, both wind power and solar power areintermittent energy sources. 

Sunlight can be converted directly into electricity using photo voltaics (PV), or indirectly withconcentrating solar power (CSP).

PV systems have traditionally used rechargeable batteries to store excess electricity.PV cells aresmall, square shaped semiconductors manufactured in thin film layers from silicon and otherconductive materials. When sunlight strikes the PV cell, chemical reactions release electrons,generating electric current. The small current from individual PV cells, which are installed in modules,can power individual homes and businesses or can be plugged into the bulk electricity grid.Photovoltaic (PV) power stations are popular in Germany and Spain. Solar thermal power stationsoperate in the USA and Spain.Concentrating Solar Power (CSP) systems use lenses or mirrors and tracking systems to focus alarge area of sunlight into a small beam. The concentrated heat is then used as a heat source for aconventional power plant.

Solar troughs -widely deployed. CSP reflectors 

Solar-Powered Outdoor Lighting Building-integrated photovoltaics

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Solar power plants face high installation costs, although it is decreasing with latest technology &development. Developing countries have started to build solar power plants, replacing other sourcesof energy generation.

For a grid-connected central station systems, a significant land ( approx.five acres of land are oftenneeded for each megawatt of capacity ) is required, which can impact existing ecosystems. PVinstallations use a little land since the panels are installed on building‘s roof. 

How it works ?

Scope of Solar Power in India

India is heading to emerge as a solar energy hub. The techno-commercial potential ofphotovoltaics in India is enormous. With GDP growing in excess of 8%, the energy ‗gap‘

between supply and demand will only widen. Solar PV is a renewable energy resource

capable of bridging this ‗gap‘.

Most parts of India have 300 - 330 sunny days in a year, which is equivalent to over 5000

trillion kWh per year - more than India‘s total energy consumption per year.

Average solar incidence stands at a robust 4 - 7 kWh/sq.meter/day.

About 66 MW of aggregate capacity is installed for various applications comprising one million

industrial PV systems - 80% of which is solar lanterns, home/street lighting systems and solar

water pumps, etc.

The estimated potential envisaged by the Ministry for the solar PV program, i.e. solar

street/home lighting systems, solar lanterns is 20 MW/sq.km.

The potential of the solar thermal sector in India also remains untapped. According to the

Ministry of New and Renewable Energy (MNRE), the estimated potential of solar water heating

systems is 140 million sq. meters collector area. Against this, the achievement till 31 March

2007 stands at 1.90 million sq. meters only. The Ministry proposes an addition of 9.50 million

sq. meters during the 11th Five-Year Plan period (2007-2012).

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Initiatives by NDPL

Solar Power Pilot Projects _ 1. 15 kW feeding to CENPEID (Training Centre2. 4 kW feeding to corporate office.Project in Progress 3. 1 MW plant on roof top of stores at KPM ( 6 Acre land )

being set up by NDPL + TATA BP Solar by 31.12.094. Installed capacity-25 kW panel ( Project cost-40 Lakhs )

CM‘s Residence ( Project cost-40 Lakhs )Generation -20% of installed capacityRs. 8 lakh fo 3 to 4 kW solar power

5. 54 kW at at Poot khurd , BawanaPlanning 6. 1000 kW on roof tops of consumers in distribution area.Proposed 7. Proposed 25 kW at DERC officeTata Power & Tata BP joined hands to set up solar plants in Delhi including roof top solar plantsconnected to grid. An arrey of PV modules ( Photovoltaic panels ) shall be laid , which will absorbsunlight & convert to electricity.Expected power by end of this Financial year : 100 MWAssumed load / consumer : 5 KW eachArea required for 10 kW – 200 sq.yardInstallation cost- Rs 14.15 LakhsTariff Rs15-16 per unitRecovery period-20 to25 yearsNo. of consumers to be covered : 20000

Incentives to the consumer to be provide by NDPL

50 % subsidy by NDPL Long term loan to the consumer @ 8% by NDPL 100% Tax rebate on I.Tax for export of solar energy to grid. By back by Utility @ Rs. 6.37 / unit

Advantages of Solar Power 

Inexhaustible fuel source Solar power is non-polluting. Unlike oil, solar power does not emit any greenhouse gases into

the air. An excellent supplement to other renewable sources . Even in areas with a lot of clouds it is possible to generate some electricity.

It has gone from a relatively expensive source of electricity to a reasonably economical one. One of the big advantages of solar power is that it does not require infrastructure, meaning

that rural electrification can advance without the need for installing power poles, generationstations, power lines, and other infrastructure.

People can feed excess power back into the electrical grid, a source of income as well. Once installed, solar cells require a little maintenance as no moving parts and they can last for

a long time. Solar power is silent power.

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Government provides incentives & subsidies for installing solar cells .The government mayalso provide a tax rebate. 

The power company may also encourage people to install solar power by paying for extrapower generated by such panels, or providing free consultations for people who are thinkingabout converting to solar power.

Using solar power can also save money. With building-integrated photovoltaics, for example,people can literally use solar cells as building materials, integrating a method of energyproduction right into a structure.

Solar power is quite flexible. You can have an array of solar panels on your roof to generatepower for your home, Solar Panels can also be fixed on thatched roof. Can feed power forhouseholds & street lighting.

and also have smaller solar cells on garden lights or street lights , that needs a small

amount of electricity. Not much wiring is required.

Versatile--is used for powering items as diverse as solar cars and satellites. Solar power is perfect for power generation in remote areas.

Disadvantages of Solar Power 

Solar panels designed to generate electricity are still fairly expensive to produce.

Since single solar panels can only generate a relatively small amount of electricity, an largearrays of solar panels are needed to provide a sufficient level of electricity to power a numberof homes.

Need a large area of solar panels to get a decent amount of power. Storage technology, such as batteries, or an alternative source of energy is always required to

ensure uninterrupted power flow. Otherwise, if there is no sun, there is simply no power. The constant bombardment of ultraviolet (UV) rays and other solar radiation often causes the

panels themselves to deteriorate. Other environmental factors like rain and dirt also affect. The initial cost of the equipment used to harness the suns energy is quite high. Pollution can be a disadvantage to solar panels, as pollution can degrade the efficiency of

photovoltaic cells. The location of solar panels can affect performance, due to possible obstructions from the

surrounding buildings.

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Wind Power- It is one of the most environmentally friendly sources of renewable energy.

Wind turbines are used to generate electricity from the kinetic power of the wind.There are two types of modern turbines - horizontal and vertical axis, both of which work similar toone another They come in different sizes from small 100 watt units for single homes to much largerones (with a blade diameter greater than 50m). These larger turbines can generate 1 MW ofelectricity.The most common used today are horizontal axis turbines with three blades (15-30m in diameter) andproduce approximately 50-350 kW of electricity. Often wind turbines are grouped together; thearrangement in called a wind farm that provides energy to an electrical grid.Vertical axis turbines are more efficient in areas with vast amount of lands and moderate windspeeds.

The power output of a turbine is a function of the cube of the wind speed. As wind speed increases,

power output increases dramatically. Areas where winds are stronger and more constant, such as

offshore and high altitude sites, are preferred locations for wind farms.

Wind Energy is highly practical in places where the wind speed is 10 to12 mph.

A Modern wind turbines range from around 600 kW to 5 MW of rated power, although turbines withrated output of 1.5 –3 MW have become the most common for commercial use.

Since wind speed is not constant, a wind farm's annual energy production is never as much as the

sum of the generator nameplate ratings multiplied by the total hours in a year. The ratio of actual

productivity in a year to this theoretical maximum is called the capacity factor. Typical capacity factors

are 20-40%, with values at the upper end of the range in particularly favourable sites. For example, a

1 MW turbine with a capacity factor of 35% will only produce an average of 0.35 MW. Over a year,

output would be .35x24x365 = 3,066 MWh instead of 24x365 = 8,760 MWh.

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The first use of wind energy was through wind mills. Wind mills had engines which used to produce

energy using wind. This energy was usually used in rural and agricultural areas for grinding, pumping,

hammering and various farm needs. Today, wind energy is used in large scale wind farms to provide

electricity to rural areas and other far reaching locations.

Wind power is the world's fastest growing electricity generation technology. Wind turbines generate

clean and green power for us

Wind farm 

A wind farm, when installed on agricultural land, has one of the lowest environmental impacts of all

energy sources.

Since, it is readily available around the globe, Wind energy may be the answer to the globe's question

of energy in the face of the rising petroleum and gas prices.

It is one of the largest forms of Green Energy used in the world today. It is a result of the sun shining

unevenly on the earth. The corresponding daily and seasonal changes in temperature consistently

generate wind, producing a fuel source that can never be depleted.

It is cheaper & cleaner source of energy. Windmill is solution to soaring oil prices and greenhouse gas

emissions fuel

In spite of the many wind power advantages, the vast potential of wind power remains largelyuntapped with less than 1% of the worldwide energy . However, as technology continues to improve

and people are made increasingly aware of its many benefits.

Wind power is growing at the rate of 30 percent annually, with a worldwide installed capacity of

121,000 megawatts (MW) in 2008.

Wind energy is being used extensively in areas like Denmark, Germany, Spain, India and in some

areas of the United States of America.

Scope of Wind Power in India

According to the Department of Energy, the costs of wind power are projected to continue to fall andmay rank the cheapest electricity source of all options by 2020.

According to the Ministry of New and Renewable Energy (MNRE), India‘s potential isconservatively estimated at 45,195 MW.

The use of wind power in India ranks fourth by worldwide comparison with an installedcapacity of 7,092 MW. In fact, the Indian government envisages a capacity addition of 10,500MW during the 11th Five – Year Plan period (2007-2012).

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India is placed at the third position in the world in terms of new construction and thiscorresponds to an overall increase of over 40% in new wind power stations.

  India‘s largest private power company, TATA Power is setting up a 100 MW wind energyproject in India.

National Thermal Power Corporation plans to install wind energy capacity of 250 MW. Hindustan Petrochemicals Company Limited and Oil and Natural Gas Commission are

foraying into the wind energy segment with wind farms of 100 - 150 MW at various sites alongIndia‘s coastline. 

SUZLON Energy Ltd - Inception in 1995. HQ-Pune. At present 5th Largest Wind turbine

manufacturer.

Capacity of Wind Turbine Generators- 600 kW to 2.1 MW

Installed more than 4490 MW in 8 states.

Customers- Small, medium & large scale businesses; Pvt. & public sector companies; Power

utilities; Independent power producers ; High net worth individuals

Wind farms in India-

Kutch ( Gujrat )- Asia‘s largest – 876 MW

Dhule Wind Farm ( Maharashtra )-2nd Largest in Asia-1350 MW

Sankaneri Wind Farm ( T.Nadu )- One of best wind power potential- 1275 MW. Windy

season extends over a large period. Karnataka- 490 MW

Rajasthan- 423 MW

MP- 53 MW

Advantages of Wind Power 

The wind is free and with modern technology it can be captured efficiently. A renewable source of clean, nonpolluting energy, perhaps second only to solar power Wind energy is friendly to the surrounding environment. No burning of fossil fuels to generate

electricity from wind energy.Emit no air pollution of greenhouse gases Wind turbines are tall & occupies a few square meters space for the base. than the average

power station. The land below can still be used. It occupies less land area per kilowatt-hour (kWh) of electricity generated than any other

energy conversion system, apart from rooftop solar energy. Turbine can be set up in just 3 months for operation. Modern wind turbines are almost silent and rotate so slowly (in terms of revolutions per

minute) that they are rarely a hazard to birds. Many people find wind farms an interesting feature of the landscape. Remote areas that are not connected to the electricity power grid can use wind turbines to

produce their own supply. Newer technologies are making the extraction of wind energy much more efficient. wind

energy is free. The cost of installation and maintenance has dramatically decreased in recentyears and future technology ensures only a continual decrease in the prices.

Wind energy in combination with solar electricity, is a great source for developed anddeveloping countries to provide a steady & reliable power.

Best suited for Remote locations at coastal areas & other windy locations. A wind power system provides a sustainable source of income for local farmers.

The local economy can benefit from wind power. In fact, it can help boost the economy of aregion substantially and also has a beneficial impact on the nation‘s economy.

Wind power also makes significant contribution to improving the local infrastructure such asroads, transportation and power.

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By and large, it is mostly affordable. Due to its generally inexpensive nature, it can be widelyafforded by a large cross section of the society.

Eco-tourism is promoted and encouraged by wind power.

Disadvantages of Wind Power 

The strength of the wind is not constant and it varies from zero to storm force. This means that

wind turbines do not produce the same amount of electricity all the time. There will be times

when they produce no electricity at all. 

Wind can never be predicted. one cannot depend completely on wind.

Large wind farms are needed to provide entire communities with enough electricity.

The noise pollution from commercial wind turbines is sometimes similar to a small jet engine or

a washing machine. It can be a nuisance for the residents of the areas.

Wind turbine construction can be very expensive. 

Many potential wind farms, places where wind energy can be produced on a large scale, are

far away from places for which wind energy is best suited. Therefore, infrastructure required

for transfer of power. 

You can erect a wind turbine anywhere and it will start generating power for you. There arelots of factors that can make an impact on the amount of energy you can generate out of wind.

The speed of wind should not be too strong because it makes turbines spin too fast. Turbineblades get ripped off by stronger winds  – excessive heat damages the alternator. Turbinetower too can't remain unaffected by the strong wind.

Wind energy is 'sustainable energy', just like solar energy and water power. 

Wind turbines are unsafe for birds too. Birds can be injured or die if they are caught up in the

wings of the turbines.

Geothermal Power-

Geothermal from the Greek words ―geo‖ and ―therme‖ mean earth‘s heat. The interior of the Earth ismade from molten rock ( extremely high temperature liquid rock known as magma ) and whatgeothermal energy does is capture the heat under the Earth‘s crust to cr eate a power source.Geothermal energy is energy obtained by tapping the heat of the earth itself, may be kilometers deepin earth or closer to surface , varies from region to region.

The heated rocks below the Earth‘s surface heat up water to create steam. Holes are thendrilled into these specific geothermal regions so that the steam can escape. During the process, thegeothermal power station drills the holes mentioned above and creates an injection well where coldwater is pumped down the well. This cold water filters through the hot rocks and then pressure is usedto bring the water back up. Once the hot water reaches the surface, it turns into the steam, which isthen harnessed for power. this steam is cleaned and filtered and then used to power turbines, whichin turn provide an electric power source.

There is also the potential to generate geothermal energy from hot dry rocks. Holes at least 3 kmdeep are drilled into the earth. Some of these holes pump water into the earth, while other holes pumphot water out. Several companies in Australia are exploring this technology.

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Capital costs for the construction of geothermal power plants are much higher than for large coal-firedplants or new natural gas turbine technologies. But geothermal plants have reasonable operation andmaintenance costs and no fuel costs.

Geothermal plants can operate around-the-clock, which increases their value from a reliability 

point-of-view, unlike some intermittent renewable fuels such as solar and wind.

Three types of power plants are used to generate power from geothermal energy:

Dry steam, Flash, and Binary plants.

Dry steam plants- take steam out of fractures in the ground and use it to directly drive a turbine thatspins a generator.

Flash plants-  With flash technology, water usually at temperatures over 200 °C, is piped from itshighly pressurized underground reservoir into a geothermal facility. Once this super-heated water isreleased, it flashes into steam that then drives a conventional turbine generator. Flash technologiesallow the geothermal fluid to expand and release gases into the atmosphere when the steam iscreated.

Binary plants- With binary technology, underground reservoir water at lower temperatures are usedfor flashing through heat exchangers. Heat from geothermal water is transferred to a second (binary)organic liquid, which flashes into vapor upon heating, which is used to drive turbines. Binarytechnology keeps the geothermal fluid contained, using heat exchangers to capture heat to providesteam. These air emissions represent tiny quantities of dissolved gases viz. carbon dioxide (CO2),methane ( CH4 ), hydrogen sulfide, ammonia, nitrogen and hydrogen. and generally do not pose any

serious environmental threat.

The condensed steam and remaining geothermal fluid from all three types of plants are injected backinto the hot rock to pick up more heat.

The disposal of water and wastewater may cause significant pollution of surface waters and groundwater supplies. Still, used geothermal fluids are generally collected and re-injected. This maintainspressures in underground reservoirs, but also allows for recycling and reuse.

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Such geothermal power sources exist in Chile, Iceland, New Zealand, United States, the Philippines ,Italy , Germany , Switzerland , Canada .

Advantages - 

When a power station harnesses geothermal power in the correct manner, there are no byproducts, which are harmful to the environment.

There is also no consumption of any type of fossil fuels. hence, geothermal energy does notemit greenhouse effect.

After the construction of a geothermal power plant, there is little maintenance to contend with. Geothermal power plants do not have to be huge which is great for protecting the natural

environment. Geothermal water, there are natural hot springs all over the world and many people enjoy the

warm waters. Geothermal waters can be harnessed to create space heating in buildings. Geothermal energy is reliable and renewable.

Disadvantages- 

You cannot just build a geothermal power plant in some vacant land plot somewhere. Thearea where a geothermal energy power plant would be built should consist of those suitablehot rocks at just the right depth for drilling.

The type of rock must be easy to drill into. It is important to take care of a geothermal sitebecause if the holes were drilled improperly, then potentially harmful minerals and gas couldescape from under ground. These hazardous materials are nearly impossible to get rid ofproperly. Pollution may occur due to improper drilling at geothermal stations.

Unbelievably, it is also possible for a specific geothermal area to run dry or lose steam.

Biomass – Solid biomass

In terms of capacity, biomass power plants represent the second largest amount of renewable energy in the nation.

Biomass – waste organic matter viz. Wood ; Cow dung ; Agricultural residues( dead leaves ) isconverted to Bio Gas.

The term "biomass" encompasses diverse fuels derived from timber, agriculture and foodprocessing wastes or from fuel crops that are specifically grown or reserved for electricity generation.Biomass fuel can also include sewage sludge and animal manure. Some biomass fuels are derived

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from trees. Given the capacity of trees to regenerate, these fuels are considered renewable. Burningcrop residues, sewage or manure - all wastes that are continually generated by society -- to generateelectricity may offer environmental benefits in the form of preserving precious landfill space .

At present, most biomass power plants burn lumber, agricultural or construction/demolitionwood wastes. Direct Combustion power plants burn the biomass fuel directly in boilers that supplysteam for the same kind of steam-electric generators used to burn fossil fuels. With biomass

gasification, biomass is converted into a gas - methane - that can then fuel steam generators,combustion turbines, combined cycle technologies or fuel cells. The primary benefit of biomassgasification, compared to direct combustion, is that extracted gasses can be used in a variety ofpower plant configurations.

Since biomass technologies use combustion processes to produce electricity, they can generateelectricity at any time, unlike wind and most solar technologies, which only produce when the wind isblowing or sun is shining. Biomass power plants currently represent 11,000 MW - the second largestamount of renewable energy in the nation.

Environmental impacts 

Whether combusting directly or engaged in gasification, biomass resources do generate airemissions. These emissions vary depending upon the precise fuel and technology used. Ifwood is the primary biomass resource, very little SO2 comes out of the stack. NOx emissionsvary significantly among combustion facilities depending on their design and controls. Somebiomass power plants show a relatively high NOx emission rate per kilowatt hour generated ifcompared to other combustion technologies.

An effect of the high nitrogen content of many biomass fuels, is one of the top air quality

concerns associated with biomass.

Carbon monoxide (CO) is also emitted - sometimes at levels higher than those for coal plants. Biomass plants also release carbon dioxide (CO2), the primary greenhouse gas. However, the

cycle of growing, processing and burning biomass recycles CO2 from the atmosphere. If this

cycle is sustained, there is little or no net gain in atmospheric CO2.  Sugar cane residue can be used as a biofuel Solid biomass is most commonly used directly as

a combustible fuel, producing 10-20 MJ/kg of heat.. One type of biomass is wood, being used by billions of people for cook every day, and heat

their homes in the winter by burning biomass, which is a major contributor to man-madeclimate change global warming.

Wood and its byproducts can now be converted through processes such as gasification intobio fuels such as wood gas, biogas, methanol or ethanol fuel; although further developmentmay be required to make these methods affordable and practical. Sugar cane residue, wheatchaff, corn cobs and other plant matter can be, and are, burned quite successfully.

Landfill Gas Power

Large municipal or industrial landfills produce gas that can be tapped to generate electricity. Microorganisms that live in organic materials such as food wastes, paper or yard clippings cause thesematerials to decompose. This produces landfill gas, typically comprised of roughly 60 percentmethane ( CH4 ) and 40 percent carbon dioxide (or "CO2"), a major contributor to global climatechange.

Through solid waste management systems, one percent of the nation's energy demand can bemanaged.

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Landfill gas is collected from landfills by drilling "wells" into the landfills.This gas is processed &combined with natural gas to fuel conventional combustion turbines or used to fuel small combustionor combined cycle turbines.

Environmental Effects: 

Use of the gas produced by landfills may reduce the harmful environmental impacts that wouldotherwise result from landfill operations.

Landfill gas electricity generation offers major air quality benefits . A landfill gas power plant burns a waste - methane --- that would otherwise be released into

the atmosphere. Methane is a highly potent agent of global climate change, having about 23times the negative impact than CO2. Landfill gas combustion produces some CO2, but theimpact of these emissions on global climate change is offset many times over by the methaneemission reductions.

Biofuel-  Plants use photosynthesis to grow and produce biomass. Biomass can be used directlyas fuel or to produce biofuels. Agriculturally produced biomass fuels, such as biodiesel, ethanol andbagasse (often a by-product of sugar cane cultivation) can be burned in internal combustion enginesor boilers. Typically biofuel is burned to release its stored chemical energy. Research into moreefficient methods of converting biofuels and other fuels into electricity utilizing fuel cells is an area isgoing on.

Liquid biofuel

Liquid bio fuel is usually either a bio alcohol such as ethanol fuel or an oil such as biodiesel orvegetable oil. Biodiesel can be used in modern diesel vehicles with little or no modification to the

engine. It can be made from waste and virgin vegetable and animal oils and fats (lipids). Virginvegetable oils can be used in modified diesel engines. The use of biodiesel also reduces emission ofcarbon monoxide and other pollutants by 20 to 40%.

In some areas corn, cornstalks, sugarbeets, sugar cane, and switchgrasses are grown specifically toproduce ethanol (also known as grain alcohol) a liquid which can be used in internal combustionengines and fuel cells. Ethanol is being phased into the current energy infrastructure. E85 is a fuelcomposed of 85% ethanol and 15% gasoline that is sold to consumers. Biobutanol is being developedas an alternative to bioethanol.

Scope of Wind Power in India

Indian climatic conditions offer an ideal environment for biomass production. Bio-energy hasremained critical to India‘s energy mix.

The current potential of surplus agro and forest residues to energy is estimated at 16,000 MWalong with an additional ―waste-to-energy‖ potential of 2,700 MW. With the setting up of newsugar mills and the modernization of existing ones, the potential of bagasse cogeneration isestimated at 5,000 MW. The cumulative installed capacity, of grid-interactive biomass andbagasse cogeneration power was 1,141 MW only, as on 31 March 2007.

The Government of India has taken a number of initiatives to promote bio-fuels.

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The Agriculture Ministry has drawn up large scale plans to plant Jatropha across the country.India currently has nearly 250,000 acres under Jatropha cultivation.

Indian Oil Corporation, Bharat Petroleum; Hindustan Petroleum ,the country‘s leading oilPSU‘s has drawn elaborate plans to plant Jatropha saplings(used to produce Biofuel) and toventure into the bio-diesel segment.

The Planning Commission of India has initiated the draft policy for bio-fuels envisaging 5%blending by 2012 and 10% by 2017.

Major institutions like the Indian Institute of Planning, Indian Institute of Chemical Technology,Indian Institute of Science, and the Indian Institute of Technology are working diligently on theresearch and development aspects of bio-diesel.

The Indian Railways has had a successful trial run of the Shatabdi Express running with a20% mix of Jatropha bio-diesel with diesel.

Technology – Hydro dynamic Fluid Coupling ; Precise Micro-pitching ; unique flexi slip mechanism for

maximizing performance.

Landfill Gas & power Pty. Ltd.-Australian agency alliance with India for promotion of this Australian

Technology.

Used for inhabitants of remote villages. Projects going on in Jharkhand ; Uttrakhand ; Rajasthan &Sikkim

References; 

Internet

Studies by CEA

Reports from Ministry of New and Renewable Energy (MNRE);

Reports from Indian Renewable Energy Development Agency (IREDA)

Energy / Power magazines

NDPL News letters

Articles from CBIP ; IEEE etc.

Super critical Thermal Power Technology - This reduces the coal intake in a power plant,

thereby improving the plant efficiency & reducing CO2 emissions. The technology burns coal

at a high pressure ( >212 kG) & Temp.( between 545 to 565 Deg C ).

Ultra supercritical & advanced ultra super critical technology – These technologies further

improve the efficiency of coal fired power plant with lesser carbon emissions. These

technologies burn coal at much higher temperature & pressure. Temp.( above 600 Deg C )

& ( >270 kG) and Temp.( above 700 Deg C ) & ( >300 kG).

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