SSC General Science & Technology Sources of Energy Notes - Energy (Renewable and Non-Renewable)

 

Energy (Renewable and Non ? Renewable)

 

GENERAL INTRODUCTION

Power development in India dates back to the pre-Independence era with the commissioning of electricity supply in Darjeeling during 1897. It was followed by the commissioning of a hydro power station at Sivasamudram in Karnataka during 1902. Through private sector controlled power supply in the pre Independence era, formation of state electricity boards during Five- Year Plans and setting up of multipurpose projects with thermal, hydro and nuclear power stations systematic growth of power supply industry in the country took place.

India is the fifth largest producer and consumer of electricity in the world. It produces 1,006 Terawatt Hours (TWh) of power which has grown at a compound annual growth rate (CAGR) of 5.5 per cent.

The Indian power sector is one of the most diversified sectors in the world. The generation of power in India is done using main commercial sources like coal, lignite, natural gas, oil, hydro and nuclear power. Other viable non- conventional sources include wind, solar, agriculture and domestic waste. The Government of India targeted capacity addition of 89 GW under the 12th Five-Year Plan (2012-17). It plans to add close to 100 GW under the 13th Five-Year Plan (2017-22). Investments of around US$ 223.9 billion have been planned for the power sector during the 12th Five-Year Plan (2012-17). There is a target of generating 10,000 MW of power through solar energy by 2017. Phase I of the Jawaharlal Nehru National Solar Mission has been very successful, wherein 1,685 MW of solar power was generated. The government of India has permitted an FDI up to 100 per cent under the automatic route for the projects of electricity generation (except atomic energy), transmission distribution and power trading. The Ministry of Power (MOP) is the nodal authority for the development of power resources in the country. The Central Electricity Authority (CEA) assists the Ministry in technical matters. An Electricity Policy was developed by the ministry which sets the tune for generation of electricity in the country.

 

(1) Energy Sector in India

By and large, the Indian energy sector has been regulated and owned by government agencies and organisations, though of late the entry of private sector has enhanced the scope for greater power generation.

 

(2) Institutional Structure

The basic institutional structure comprises of a nodal ministry at the centre for each energy supply sector, which is the primary agency for policy formulation support in decision-making, and implementation by state governments; state- level nodal agencies, public sector undertakings, and technical and research institutions. The Union Government plays a dominant role in the energy sector and it is mainly due to the fact that the subject energy has been placed in the concurrent list of the Seventh Schedule of the Constitution of India.

 

(3) India's Energy Policy

The Energy Policy of India speaks about the goals with respect to short medium and long terms, which are as follows:

·         Short Term: Development of domestic conventional energy resources and demand management without affecting economic growth.

·         Medium Term: Energy conservation, improved energy efficiency.

·         Long Term: Development of technologies to exploit resources of thorium. Development of renewable energy on a large scale.

 

ULTRA MEGA POWER PROJECTS (UMPPs)

 

IYB Definition

Ultra Mega Power Projects (UMPPs) are being promoted with a view to provide power to everyone at a reasonable rate and ensuring fast capacity addition by the Central Government as an initiative, facilitating the development of UMPP of 4000 MW capacity each under tariff based international competitive bidding route.

 

UMPPs
	Proposed	Type	State	Status	Remark
1.	Sasan UMPP	Coal Pithead	Madhya Pradesh	Reliance Power Ltd.	The first 660 MW unit was commissioned in 2013.
2	Mundra UMPP	Coastal	Gujarat	Tata Power Ltd.	All five units have been commissioned; units are fully commercially operational
3.	Tilaiya UMPP	Coal pithead	Jharkhand	Reliance Power Ltd.	Land acquisition and preliminary works are under progress
4.	Krishnapuram UMPP	Coastal	Andhra Pradesh	Reliance Power Ltd.	Scheduled for commissioning during the 12th five ? year plan
5.	UMPP Chhattishgarh	Coal pithead	Chhattisgarh	Bidding state
6.	UMPP IN Orisha	Coal pithead	Odisha	Proposed
7.	UMPP- Tamilnadu	Coastal	Tamil Nadu
8.	UMPP ? Maharashtra	Coastal	Maharashtra

 

New Sites for UMPPs
Nyunapali village in Prakasham district	Andhra Pradesh
Husianabad, Deoghar district	Jharkhand
Bijoy Patna, Chandbali of Bhadark district	Odisha
Narla and Kasinga Subdivision of Kalahandi district	Odisha
Kakwara in Banga district	Bihar
ETA UMPP	Uttar Pradesh

 

NON-CONVENTIONAL ENERGY

Non-conventional or renewable energy provides power from any source that can be replenished. Most renewable systems depend on solar energy directly or through the natural sources such as wave power, hydroelectric power, wind power via wind turbines, or solar energy collected by plants (e.g., alcohol fuels). Besides, the gravitational force of the Moon can be harnessed to using tidal power stations. The heat trapped in the center of the Earth is also a non-conventional source which can be used via geothermal energy systems. Other examples are energy from bio-fuel and fuel cells.

Renewable energy resources are non-polluting. It is a huge advantage. However, some of the sources such as wind energy can be unreliable and therefore, lose their effectiveness in providing a constant supply of power.

Despite inherent problems with the technology generating renewable energy sources, an increase in environmental pressure is forcing development at an increasing pace. Worldwide wind-power generation had exceeded 30 MW and reached an annual growth rate of 25% by the end of 2007.

India has a vast potential for the production of power from non-conventional and renewable energy sources.

 

Advantages

·         Renewable source

·         Inexhaustible

·         No pollution/minimum pollution

·         Ultimately sourced to solar energy

·         Not always the primary source

 

Disadvantages

·         Subject to vagaries of nature

·         Present level of technology needs vast investment

·         Gestation period is very high.

 

Indian Scenario for Renewable Energy

·         The importance of increasing use of renewable energy sources in the transition to a sustainable energy base was recognised in India in the early 1970s.

 

·         During the past quarter century, a significant effort has gone into the development, trial and induction of a variety of renewable energy technologies for use in different sectors of the economy and sections of society in India.

 

Largest Renewable Energy Programmes

·         India has today among the world's largest programmes for renewable energy. Its activities cover all major renewable energy sources of interest to us such as biogas, biomass, solar energy, wind energy, small hydro power including other emerging technologies. There are programmes for resource assessment, R&D, technology development and demonstration in each of these domain. There are several renewable energy systems and products that are now commercially as well as economically viable in contrast to fossil fuels, particularly with regard to environmental costs of fossil fuels.

 

·         The Power Ministry is concerned with the implementation of these programmes for development, demonstration and utilisation of various renewable energy based technologies viz. solar thermal; solar photo voltaics; wind power generation and water pumping; biomass combustion/co-generation; small, mini, and micro hydro power; solar power; utilisation of biomass-gasifiers, briquetting, biogas, improved chulha (cook-stove); power generation/energy recovery from urban, municipal and industrial wastes; and tidal and geothermal power generation for heat applications.

 

 

·         The Ministry also deals with other emerging technologies such as fuel cells, chemical sources of energy, alternative fuel for surface transportation and hydrogen energy etc.

                  A renewable resource is a natural resource which, if harvested sustainably, can be regenerated after its use. Ecosystems produce resources and process them. The main driving force behind the ecological system is the solar energy that provides energy for the growth of plants in forests, grasslands and aquatic ecosystems. The organic component is recycled by the forests slowly by continuously returning its dead material, leaves and branches to the soil. However, recycling is done by the grasslands at a faster rate than forests, as the grass dries up after the rains every year. The aquatic ecosystems need solar energy and have cycles of growth with the spread of plant and animal life; the Sun also works as the major force driving the water cycle.

It is important to understand that although water and biologically living resources such as forests, grasslands and wetlands are considered renewable they are, in fact, renewable only within a certain limit. If over-utilised and/or degraded beyond that limit, they lose their capacity to regenerate.

Non-renewable resources, on the other hand, are natural resources that take millions of years to regenerate and are irreplaceable after consumption. They are often present in a fixed amount only and are often consumed at a faster rate than the environment's capacity to regenerate them. Fossil fuel' such as coal, petroleum and natural gas are some examples of non-renewable resources.

 

NATURAL RESOURCES AND ASSOCIATED PROBLEMS

Natural resources include those resources that are derived from the environment. Water, air, minerals, oil and products gained from forests are some examples of natural resources.

 

THE UNEQUAL CONSUMPTION OF NATURAL RESOURCES

A major part of our natural resources are consumed in the technologically advanced or 'developed' world presently. It is usually termed as 'the North' 'The South' or 'the developing nations' that includes India and China, also exploit natural resources because of their huge demography. However the consumption of resources per capita (per individual) in the developed countries is close to 50 times more than most developing countries. Over 75% of the global industrial waste and greenhouse gases (GHGs) are generated by developed countries.

Energy from fossil fuels form the main source of energy in developed nations. Their per capita consumption of food and other products is also much high. This results in generation of larger quantities of waste. Food sources from animals require even more amount of land. Therefore, countries highly dependent on meat-based diets need more amount of land resources for pasture than those countries where people are mainly vegetarian. This is the consumption pattern which can also be measured in terms of a nation or city's Ecological Footprint (EF). This is a measure of human demand on the Earth's resources with regard to the Earth's capacity to regenerate those resources. Thus, the per capita EF provides a means to compare consumption and lifestyles while checking this against the Earth's ability to provide for this consumption. As of 2006, the US footprint per capita was 9.0 global hectares (gha), while India's was 0.8 gha. While India's footprint is much smaller than the world average of 2.2 gha, it is important to know that our footprint has doubled since the 1960s due to population growth. This accelerated degradation of our natural capital is unsustainable.

 

PLANNING LAND USE

Land constitutes as an important resource which is vital for food production animal husbandry, industry and for our growing human settlements. Such intensive utilization are frequently done at the cost of 'wild lands' - our remaining forests, grasslands, wetlands and deserts. Therefore it is a requisite to have a land use policy that examines how much land must made available for venous purposes including suitability of its location where alternate locations where industrial complexes or dams can be constructed are, but a natural wilderness cannot come up artificially. Scientists today believe at least 10% of the land and water bodies must be conserved sustainable and long-term needs.

Land as a resource is now under serious threat due to an increasing requirement to produce sufficient quantities of food for an ever-increasing human population. It is also affected by degradation due to misuse. Land and water resources are also polluted by industrial waste including rural and urban sewage. It is getting diverted for short-term economic gains. Natural Wetlands have a great value from ecological point. They are being drained for agriculture and other purposes and semi ? arid land is being irrigated and overused.

Rapid destruction of forests is the most damaging change is land use in recent times, both in India and in rest of the world. In the long term, the forests provide benefits which are far greater than the shot- term gains produced by converting forested lands to other uses.

 

NEED FOR SUSTAINABLE LIFESTYLES

The quality of human life and the quality of ecosystems on Earth indicate sustainable use of natural resources. Clear indication of sustainable lifestyle a human life is given by:

·         increased longevity,

·         an increase in knowledge, and

·         Growth in income.

These three together are known as the 'Human Development Index':

The indicators of the quality of the ecosystems are more difficult to assess.

They are:

·         increased longevity,

·         a stabilised population or the percentage of species loss,

·         species diversity in ecosystems, and

·         The state of 'naturalness' of ecosystems.

 

RENEWABLE AND NON-RENEWABLE ENERGY SOURCES

A feasible source of energy is one that provides adequate amount of energy in a usable form over a long period at economical cost. These sources are of two types:

(1) Renewable resources which can be generated and harvested continuously in nature. They are inexhaustible. Wood, solar energy wind energy, tidal energy, hydropower, biomass energy, bio-fuels, geo-thermal energy and hydrogen are some of the prominent examples. They are also termed as non-conventional since they can be used repeated.

(2) Non-renewable resources get exhausted after use. They have accumulated in the nature over a longer period of time and cannot be quickly replenished. Coal, petroleum, natural gas and nuclear fuel' like uranium and thorium are some of the examples.

Wood is a renewable resource as we can get new wood by growing a sapling into a tree within 15-20 years but it has taken millions of years for the formation of coal from trees and cannot be regenerated in our life time hence coal is not renewable. We will now discuss various forms of renewable and non-renewable energy resources.

 

Solar Energy

Sun is the ultimate source of energy. It directly or indirectly accounts for all other forms of energy. Sun releases enormous quantities of energy in the form of heat and light because of nuclear fusion. The solar energy received as the Earth space is approximately 1.4 kilojoules/second/\[{{m}^{2}}\]. This is known as solar constant.

Traditionally, we have been using solar energy for drying clothes an-: food-grains, preservation of eatables and for obtaining salt from sea-water. We have now developed several techniques for harnessing solar energy. Some important solar energy harvesting devices are mentioned here:

 

(i) Solar heat collectors: They are active or passive in nature. Passive solar heat collectors are natural materials like stones or brick. Materials like glass also form a passive heat collector. It absorbs heat during the daytime and release it slowly at night. Active solar heat collectors pump heat absorbing medium (air or water) through a small heat collector which is generally placed on the top of the building.

 

(ii) Solar cells; Solar cells are also known as photovoltaic cells or PV cells. They are made of thin wafers of semiconducting material like silicon and gallium. Solar radiations falling on semiconductor- create a potential difference causing a flow of electrons that produce- electricity. Silicon can be obtained from silica or sand, which is abundantly available and inexpensive. Efficiency of the PV cells can be improvised using gallium arsenide, cadmium sulphide or boron the potential difference produced by a single PV cell of \[4\,\,c{{m}^{2}}\] size is about 0.4-0.5 volts. It generates a current of 60 millamperes.

A group of solar cells joined together in a definite pattern form a solar panel which can harness a large amount of solar energy and can produce electricity enough to run street-light, irrigation water pump, etc.

Solar cells have wide applications in calculators, electronic watches, street lighting, traffic signals, water pumps, etc. They are also used in the manufacturing of artificial satellites for power generation. Solar cells also find use in operating radio and television. They are used more in remote areas because of lack of conventional electricity supply.

 

(iii) Solar cooker: Solar cookers reflect solar light and heat using a mirror directly on to a glass sheet which covers the black insulated box where the raw food is placed for cooking. A solar cooker of new design has a spherical reflector (concave or parabolic reflector) instead of plane mirror that provides effective heating and greater efficiency.

Solar cookers help preserve nutrition due to slow heating. However it outlives its utility during night or on cloudy days. Moreover, the direction of the cooker has to be corrected in accordance to the direction of the sun rays.

 

(iv) Solar water heater: It is made of an insulated box painted black inside. It has a glass lid to receive and store solar heat. It has a black painted copper coil inside the box through which cold water is made to flow in. The heated water is made to flow out into a storage tank which is then supplied through pipes into buildings like hotels and hospitals.

 

(v) Solar furnace: It consists of thousands of small plane mirrors. They are arranged in concave reflectors, all of which collect the solar heat and produce as high a temperature as\[3000{}^\circ C\].

 

(vi) Solar power plant: Solar energy is harnessed on a large scale by using concave reflectors. They cause boiling water to turn into steam.

A steam turbine drives a generator to produce electricity. A solar power plant of 50 KW capacity has been installed at Gurgaon in Haryana.

 

Wind Energy

The high speed winds possesses lot of energy in the form of kinetic energy due to their motion. Sun is the main driving force of the winds. The wind energy is harnessed by wind mills whose blades rotate continuously due to the force of the striking wind. The rotational motion of the blades generates electricity. It also drives number of machines like water pumps, flour mills and electric generators. A wind farm has large number of wind mills installed clusters They feed power to a utility grid and produce large amount of electricity These farms have ideal locations in coastal regions, open grasslands or hilly regions, particularly mountain passes and ridges where the winds are strong and steady. The minimum wind speed requirement for satisfactory working of a wind generator is 15 km/hr.

India has an estimated wind power potential of 20,000 MW, however presently, we generate about 1020 MW. The largest wind farm of our country is located near Kanyakumari in Tamil Nadu. It generates about 380 MW of electricity. Wind energy is the second fastest growing source of energy since 1990. It is going to be the cheapest source of energy. Moreover, it does not cause any air pollution. After the initial installation cost, it becomes cheaper to generate power. It is estimated that by the middle of the century wind power would be a reliable source of power and it will supply more than 10% of world's electricity.

 

Hydropower

Flowing water of a river is obstructed and collected by constructing a big dam. The stored water is allowed to fall from a height. The blades of the turbine move with the fast moving water which in turn rotates the generator and produces electricity. A mini or micro hydel power plants can be constructed on the rivers in hilly regions for harnessing the hydro energy on a smaller scale, however, the minimum height of the waterfalls should be 10 meters. The hydropower potential in India is estimated to be close to \[4\times 10\] 11 KW hours.

Hydropower is renewable and free from pollution. The hydropower projects are multi-purpose that helps in controlling floods, irrigation, navigation, etc. However, big dams are often linked with a number of adverse environmental impacts.

 

Tidal Energy

Tides are produced by gravitational forces of the Sun and the Moon. It contains huge amounts of energy. The 'high tide' and 'low tide' refer to the alternate rise and fall of water in the oceans. There should be a difference of several metres between the height of high and low tides to spin the turbines. Tidal barrage can be constructed in order to harness tidal energy. During high tide, the sea-water flows into the reservoir of the barrage and turns the turbine which in turn produces electricity by rotating the generators. During Low tide, sea water is stored in the barrage reservoir which flows out to the sea after turning the turbines.

There are only few sites in the world where tidal energy can be suitably harnessed. The Bay of Fundy, Canada having 17-18 m high tidal range has a power generation potential of 5,000 MW. The tidal mill at La Rance, France is one of the first modem tidal power mill. In India, Gulf of Kutch, Gulf of Cambay and the Sunderban deltas are the potential sites for tidal power generation.

 

Ocean Thermal Energy (OTE)

The differential of the water temperature of the sea is a potential source of energy. This is due to the difference in temperature of water at the surface and at the deeper levels is called Ocean Thermal Energy. There has to be a difference of \[20{}^\circ C\] or more between the surface water and deeper water level Of the ocean for feasible operation of Ocean Thermal Energy Conversion OTEC) power plants. The warm surface water of ocean is used to boil a liquid like ammonia whereas the high pressure vapours of the liquid formed by boiling are potentially used to turn the turbine of a generator and produce electricity. The colder water from the deeper ocean is pumped to cool and condense the vapours back into the liquid form. Thus the process keeps on going continuously for 24 hours a day.

 

Geothermal Energy

The heat energy harnessed from deep inside the Earth is called geothermal energy. There are high temperature and high pressure steam fields that exist below the Earth's surface. This heat may have its source in the fission of radioactive material naturally present in the rocks. In some places, the steam or the hot water have their source beneath the ground in naturally formed cracks. They are called natural geysers as those found in Manikaran, Kullu and Sohna, Haryana.

Sometimes the steam or boiling water underneath the Earth does not find any opening to come out. We can drill a hole up to the hot rocks and make the steam or hot water gush out using a pipe. The high pressure steam turns he turbine of a generator to produce electricity.

There are several geothermal plants working successfully in USA and New Zealand.

 

Biomass Energy

Biomass is the organic matter produced by the plants or animals which includes wood, crop residues, cattle dung, manure, sewage, agricultural wastes, etc. The energy produced from the biomass is of the following types:

 

(a) Energy plantations: Solar energy is captured by the green plants through the process of photosynthesis and converted into biomass energy. There are many fast growing trees such as cottonwood, poplar and Leucaena including non-woody herbaceous grasses, crop plants ; like sugarcane, sweet sorghum and sugar beet, aquatic weeds like water hyacinth and sea-weeds and carbohydrate rich potato, cereal ; etc. These collectively form important source of energy plantations. These are either burnt directly or converted into combustible gas or fuels by the process of fermentation.

 

(b) Petro-crops: Certain latex-containing plants like Euphorbias and oil palms are rich in hydrocarbons, They can potentially yield an oil-like substance under high temperature and pressure. This oily material may be burnt in diesel engines directly or may be refined to form gasoline. These plants are popularly known as petro crops.

 

(c) Agricultural and urban waste biomass: Crop residue, bagasse (sugarcane residues), coconut shells, peanut hulls, cotton stalks etc. are some of the common agricultural wastes. They are burnt to produce energy. Besides, animal dung, fishery and poultry waste and even human wastes comprise as source of biomass energy. Brazil generates 30% of its electricity by burning bagasse. Animal dung cakes are burnt to produce heat in rural India. Majority of rural heal energy requirements are met by burning agricultural wastes, wood and animal dung cakes. In rural areas biomass form the principle means of fuel that are burned in open furnaces called 'Chulhas' which usually produce smoke. They are not so efficient (efficiency is < 8%). Now improved Chulhas with tall chimneys have been designed. They have a very high efficiency and are smokeless.

The burning of plant residues or animal wastes causes air pollution. It produces lot of ash as waste residue. The burning of dung destroys essential nutrients like N and P. It is, therefore, more feasible to convert the biomass" into biogas or bio fuels.

 

Biogas

Biogas consists of mixtures of methane, carbon dioxide, hydrogen and hydrogen sulphide gases, of which the major constituent is methane. It is produced by anaerobic degradation of animal wastes (sometimes plant wastes) in the presence of water. There is breakdown of organic matter by bacteria in the absence of oxygen. Biogas is a non-polluting, clean and low cost fuel. It is very useful for rural areas where animal and agricultural wastes are available in plenty. India has the largest stock of cattle population in the world (240 million). It has tremendous potential for biogas production. From cattle dung alone, we can produce biogas of a magnitude of \[22,500\,\,m{{m}^{3}}\] annually. A sixty cubic feet Gobar gas plant can produce sufficient gas in the form of energy to serve the needs of one average family.

There are following advantages of biogas:

·         It is cheaper, clean and non-polluting.

·         There is no need of storage problem.

·         The sludge formed as left over is a rich source of nutrients and can be used as fertilizer.

·         Air-tight digestion/degradation of the animal wastes is a safer option since it prevents health hazards which normally occur in case of direct use of renewable and non-renewable resources.

There are two types of biogas plants used in our country:

(1) Floating gas-holder type and

(2) Fixed-dome type.

 

(1) Floating gas-holder type biogas plant: This type has a well-shaped digester tank constructed using bricks which is placed under the ground. An inverted steel drum floats over the digester to hold the bio-gas produced. It is controlled by a pipe and the gas outlet is regulated by a valve. The digester tank is divided using a partition wall and one side of it receives the dung-water mixture through the inlet pipe while the other side discharges the spent slurry through the outlet pipe. Sometimes there is corrosion of the steel gas-holder that leads to leakage of biogas. The tank has to be repaired and painted again for maintenance. There is another design which is discussed below:

 

(2) Fixed-dome type biogas plant: The structure of the fixed-dome type is almost similar to the previous type. However, instead of a floating steel gas-holder there is a dome-shaped roof made of concrete. There is a single unit in the main digester with both inlet and outlet chambers. The Ministry of Non-Conventional Energy Sources (MNES), now renamed as Ministry of New and Renewable Energy Sources has been promoting the Biogas Programme in India. Out of the various models, the important ones used in a rural set-up are KVIC Model (Floating drum type), Deenbandhu Model (Fixed dome type), Pragati Model (floating drum type), Janata Model (Fixed dome type), Ganesh Model (KVIC type but made of bamboo and polythene sheet) and Ferro- cement digester Model (KVIC type with Ferro-cement digester).

 

Biofuels

Biomass can be fermented to produce alcohols like ethanol and methanol. They form as a potential source of fuels. The production of ethanol can be done using carbohydrate rich substances like sugarcane, corn and sorghum (jowar). Such fuels bums clean and causes almost no pollution. However, its calorific value is lesser and therefore, produces much less heat compared to petrol. It is also an excellent substitute of kerosene and its combustion is as clean as LPG.

·         Gasohol is a common fuel used in Brazil and Zimbabwe for running cars and buses. In India gasohol has been planned to be used on a trial basis near Kanpur. It is a mixture of ethanol and gasoline.

·         Methanol is also very useful. It bums at a lower temperature than gasoline or diesel. Therefore, it may lead to development of sleek design instead of bulky radiator. Methanol too is a clean, non-polluting fuel. It can be easily obtained from woody plants and ethanol produced from grain-based or sugar-containing plants.

 

Hydrogen as a Fuel

As hydrogen bums in air, it combines with oxygen to form water generating large amount of energy. Due to its higher calorific value hydrogen can serve a- an excellent fuel. This is also non-polluting. Hydrogen can be easily producer by thermal dissociation, photolysis or electrolysis of water as follows:

(i) Hydrogen \[({{H}_{2}})\] is produced by the thermal dissociation of water (at \[3000{}^\circ K\]or above).

(ii) Hydrogen is produced thermo chemically, by chemical reaction o' water with some other chemicals in 2-3 cycles.

(iii) Electrolytic method dissociates water into hydrogen \[({{H}_{2}})\] and oxygen \[({{O}_{2}})\] using a current flow through it.

(iv) Photolysis implies breakdown of water in the presence of sunlight to release hydrogen. Green plants and micro-algae use photolysis of water during photosynthesis. Efforts have been made to trap hydrogen molecules produced during photosynthesis.

However, hydrogen is highly inflammable and explosive in nature Therefore, safe handling is required for using hydrogen as a fuel. Storage and transportation of hydrogen as a fuel is difficult. Being very light, it should be stored in bulk.

Presently, \[{{H}_{2}}\] is used in the form of liquid hydrogen as a fuel in spaceships. It can be utilized in the fuel cells to generate electricity. Hydrogen is burnt in the open air or oxygen in the presence of an electrolyte to produce electricity in a fuel cell.

 

LIMITATIONS OF NON-RENEWABLE ENERGY SOURCES

These are the fossil fuels like coal, petroleum, natural gas and nuclear fuels. These were formed by the decomposition of the remains of plants and animals buried under the Earth millions of years ago. The fuels are very precious because they have taken a long time to form and if we exhaust their reserves at such a fast rate as we have been doing, ever since we discovered them, very soon we will lose these resources forever. Until now we are heavily dependent on fossil fuels for energy needs.

 

Coal

Coal was formed 255-350 million years ago in the hot, damp regions of the Earth during the Carboniferous Age. The ancient plants along the banks of rivers and swamps were buried after death into the soil and, due to the heat and pressure, gradually got converted into peat and coal over millions of years of time. There are mainly three types of coal, namely anthracite (hard coal), bituminous (soft coal) and lignite (brown coal). Anthracite coal has maximum carbon (90%) and calorific value (8700 kcal/kg).) Bituminous, lignite and peat contain 80%, 70% and 60% carbon, respectively. Coal is the most abundant fossil fuel in the world. At the present rate of usage, coal reserves are likely to last for about 200 years and if its use increases by 2% per year, then it will last for another 65 years. India has about 5% of the world's coal and Indian coal is not very good in terms of heat capacity. Major coal fields in India are Raniganj, Jharia, Bokaro, Singrauli, and Godavari valley. The coal states of India are Jharkhand, Odisha, West Bengal, Madhya Pradesh, Andhra Pradesh and Maharashtra. Anthracite coal occurs only in Jammu and Kashmir.

When coal is burnt it produces carbon dioxide, which is a greenhouse gas responsible for causing enhanced global warming. Coal also contains impurities like sulphur. Therefore as it bums, the smoke released contains toxic gases like oxides of sulphur and nitrogen.

 

Petroleum

There are 13 countries in the world having 67% of the petroleum reserves which together form the Organization of Petroleum Exporting Countries (OPEC). About 1/4th of the total oil reserves are in Saudi Arabia.

At the present rate of usage, the world's crude oil reserves are estimated to get exhausted in another 40 years. Some optimists, however, believe that there are some yet undiscovered reserves. Even then the crude oil reserves will last for yet another 40 years or so. Crude petroleum is a complex mixture of alkane hydrocarbons. Hence, it has to be purified and refined by the process of fractional distillation, during which different constituents separate out at different temperatures. A large variety of petroleum products are obtained from it\[-\] petroleum gas, diesel, kerosene, petrol, fuel oil, lubricating oil, paraffin wax, asphalt, plastic, etc.

Petroleum is relatively a cleaner fuel compared to coal. It bums completely without leaving any residue. It is also easier to transport and store. Hence, petroleum is preferred amongst all the fossil fuels.

 

Liquefied Petroleum Gas (LPG): There are three main components of petroleum. The first is butane, and the other being propane and ethane. The petroleum gas is easily converted to liquid form as LPG when kept under pressure. It is odourless, but the LPG in our domestic gas cylinders gives a foul smell. This is, in fact, due to ethyl mercaptan, a foul smelling gas which is added to it to detect leakage instantaneously from the cylinder.

There are many oil fields in India, located at Digboi (Assam), Gujarat Plains and Bombay High offshore areas and in the deltaic coasts of Godavari, Krishna, Kaveri and Mahanadi.

 

Natural Gas

Natural gas mainly contains methane (95%) with small amounts of propane and ethane. It is a fossil fuel. The deposits of natural gas mostly accompany oil deposits because of its nature of formation by the decomposed remains of dead animals and plants buried under the earth. Natural gas can be termed as the cleanest fossil fuel. It can also be easily transported through pipelines.

It has a high calorific value of about 50 kJ/g and bums without any smoke. There are huge amount of natural gas deposits located in many parts of the world. Russia has the maximum reserves (40%), followed by Iran (14%) and USA (7%). Natural gas reserves are found associated with all the oil fields in India. There are many new gas fields that have been found in Tripura, Jaisalmer, offshore area of Mumbai and the Krishna and Godavari Delta.

Natural gas is also used as a domestic and industrial fuel. It is used as a fuel in thermal power plants for generating electricity whereas it acts as a source of hydrogen gas in the fertiliser industry. It is also used as a source of carbon in the tyre industry.

 

Compressed Natural Gas (CNG): Compressed Natural Gas has become a credible alternative to petrol and diesel for transport of vehicles. Delhi has fully switched over to CNG where buses and auto rickshaws use it as fuel. CNG use has greatly helped reduce vehicular pollution in Delhi.

 

Synthetic Natural Gas (SNG): It is a mixture of carbon monoxide and hydrogen. It provides a link between fossil fuel and the substituted natural gas. The process of gasification transforms low grade coal into synthetic gas. It is followed by catalytic conversion to methane.

 

BIOMASS POWER/COGENERATION

Aims and Objectives

·         The Government Programmes on Biomass Power/Cogeneration has targeted at establishing feasible and viable power generation from biomass materials which are either wasted or sub-optimally utilised. It aims at maximising power generation from sugar mills.

 

Resources and Technology Options

·         Biomass includes agricultural wastes, straw, stalks, stems and fines, including processing residues such as shells, husks, deoiled cakes, forestry residues and biomass grown in area specially dedicated to energy plantations. There are many conversion technologies that include combustion/incineration, gasification, pyrolysis, etc. Gas/ steam turbine, dual fuel engine/gas engine, or combination thereof are used either in generation of power alone or in the cogeneration of more than one energy forms - steam and power.

 

Potential

·         India is the largest producer of cane sugar and the Ministry is implementing the world's largest cogeneration programme in sugar mills.

·         There exists an established potential of 3,500 MW of power generation through bagasse based cogeneration in sugar mills.

·         Biomass power generation from surplus agricultural residues is also being actively promoted.

·         A capacity of 420 MW has so far been commissioned and 488 MW is under installation since 2002.

·         Cogeneration, i.e., multiple and sequential use of a fuel for production of steam and power in a process industry, aims at surplus power generation in industries such as sugar mills, paper mills, rice mills, etc., where biomass resources are either generated or consumed in their main processing/production process.

·         Potential in cogeneration: 19,500 MW.

 

Biomass Gasifiers and other Biomass Energy Programmes

·         In the area of small scale biomass gasification, significant technology development work has made India a world leader.

·         Power production in the range of few kW to 500 kW is possible in a Biomass gasifiers.

·         Indigenously developed small biomass gasifiers have successfully undergone stringent test.

·         It is now being exported not only to developing countries of Asia and Latin America, but also to Europe and USA.

·         There are large number of installations that have come up to provide power to small scale industries including electrification of a village or group of villages.

·         The Biomass Gasifier Programme has been suitably modified to bring about better quality and cost effectiveness.

·         The SUTRA which is an integrated biomass energy based project has been implemented at a rapid rate in seven villages of the two talukas in Karnataka.

·         The programmes on biomass briquetting and biomass production are being reviewed. There is a new proposal on power production which has been linked to energy plantations.

·         There are five Gasifier Action Research Projects currently being implemented in selected technical institutions in different parts of the country. It aims at providing technical support to the gasifier programme.

·         Biomass includes straws, stalk, and stems; agro-industrial processing residues, forestry residues including biomass generated from especially dedicated energy plantations, etc.

 

Applications

·         Thermal/Heat

·         Mechanical water pumping for irrigation, etc.

·         Power generation (standalone/grid connected) including village electrification

·         Industrial applications.

 

Thrust Area for Research and Development

·         Cost reduction of gasifier systems

·         Development of application packages

·         For tea drying

·         For plywood industry and other industries.

·         Development of qualifying tests and up gradation of standards.

·         Optimisation of dual-fuel engines for rural grid scale.

 

Progress

·         1796 gasifier systems of different unit capacities (3 to 500kW) aggregating 51.30 MW have been installed (as on 30.04.2002).

 

RURAL ENERGY PROGRAMMES

·         The people in rural areas largely depend on fuel-wood, crop residues, and cattle dung for meeting their basic energy requirements.

·         The consumption of fuel-wood has far exceeded its supply with increasing population pressure. This has has led to deforestation and desertification. Similarly, the conventional practice of burning cattle dung and crop residues for meeting energy requirements has deprived the agricultural lands of much needed manure. This has caused loss of soil fertility.

·         Besides, the inefficient burning of biomass in traditional chulhas creates high level of indoor air pollution, which in turn causes eye and respiratory related illness among women and children in the rural areas. Therefore, the government has been promoting biogas units as a strategy for recycling of cattle dung to harness its fuel value without destroying the manure value. Toilet-linked biogas plants are also being made popular for sanitary treatment of human wastes. There are variety of smokeless efficient chulhas. It is being popularised to conserve fuel-wood and reduce domestic air pollution.

·         Capabilities are being developed for planning and implementation of these area-based energy plans and projects at selected blocks.

·         The Ministry has taken up following programmes for meeting the rural energy requirements:

v  Biogas Development

v  National Programme on Improved Chulhas

v  Integrated Rural Energy Programme

 

INTEGRATED RURAL ENERGY PROGRAMME (IREP)

·         IREP was conceptualized during the Sixth Five-Year Plan. It was launched as a centrally sponsored Scheme in the Seventh Plan.

·         The programme was transferred in 1994-95 from the Planning Commission to MNES.

·         IREP aims at promoting an optimum combination of both conventional and non-conventional energy sources in selected blocks of the count

·         The objectives of the programme are as follows:

(i) The most cost effective combination of various energy sources and options to be provided for meeting the requirements of sustainable agriculture. This would facilitate rural development by giving due weightage to environmental considerations.

(ii) IREP block to have minimum domestic energy needs for cooking and lighting.

(iii) Development of capabilities in States/UTs for preparation and implementation of Block Level Energy Plans and Projects.

(iv) Promoting large scale peoples participation in the planning and implementation of programmes. Involvement of panchayats. Voluntary organisations and institutions at the micro level for the implementation of the IREP projects to be ensured.

(v) Setting up and strengthening of the mechanisms and co-ordination arrangements for linking micro level planning and rural energy) and economic development so as to ensure regular and planned flow of energy inputs for meeting the requirements of various end-users in the IREP projects.

(vi) Financing of the programme by supplementing available Central and State budgetary support with resources to be mobilised by the panchayais and other local bodies and peoples' participation.

 

Cumulative Achievement

·         860 Blocks have been sanctioned for establishing Block level IREP Projects Cells.

·         22 National Pilot Projects have been sanctioned. Technical backup units are functioning in 19 states/UTs.

·         Regional IREP training centers are functioning at Lucknow, Uttar Pradesh and Delhi. In addition, three more centers are being established at village Amrol, District Kheda, Gujarat; Jakkur near Bangalore. Karnataka; and Shillong, Meghalaya.

 

 Salient Features of National Pilot Project (NPP)

·         To build up a mechanism for increasing the necessity of utilising energy in an efficient way among rural masses.

·         To meet the basic minimum energy needs for cooking and lighting of IRDP beneficiary in the NPP Block on 100% coverage basis.

·         Jointly funded by state and Centre on 50:50 basis, upto Rs.10.00 Lakh for each NPP.

·         To serve a model IREP Block by strengthening/updating the Links/components of the on-going IREP.

·         Make IREP more participatory, cost, effective, sustainable and accessible.

 

URJAGRAM

·         The Urjaran scheme has been develop for the following objective:

·         To make remote and far-flung rural areas self-sufficient in energy.

·         This is to be accomplished through locally available renewable and non ? conventional energy such as Sloar energy, bio energy, wind energy, etc.

·         Not only for domestic needs, but these resources can be used for agriculture operation, cottage industry, community facility. For example ? in an urjaran ? a community biogas plant may be there.

 

CHEMICAL SOURCES OF ENNERGY

The development and improvising fuel cell technology form the main objective of the Chemical Sources of Energy Programme. Fuel cell technology produce electricity, water and heat through reaction between hydrogen and oxygen. The technology offers high conversion efficiency, modularity, compactness and noise ? free operation.

·         Hydrogen is the primary fuel for fuel cells. There are other fuels that can also be used to produce hydrogen gas with the aid of reformers. Modularity of the fuel cells make it an ideal candidate for de-centralized power generation including other uses.

·         Prototypes of proton exchange membrane fuel cells (PEMFCs) and phosphoric acid fuel cells (PAFCs) have been develop in kW size. These prototypes have been used demonstrably for power generation, industrial and transport sectors.

·         A vehicle using fuel cell with indigenously developed PEMFC has been under field performance evaluation.

·         Efforts have been made for the indigenously production and wider application of fuel cell system in the country. The can remove our dependence on scarce fossil fuels. It will also preserve the environment.

This programme focuses on fuel cells in order to produce electricity, water and heat through reaction between hydrogen and oxygen. Hydrogen is used as the primary fuel in the fuel cells. It can also be extracted from other fuels through a fuel reformer. Fuel cells are ideally suited for distributed power generation because of its modular nature. Small fuel cell power plants can be potentally used for power generation including other application such as industrial, residential and transport. A 10 KW proton exchange membrance fuel cell is being used in a fuel cell electric vehicle, in addition to a battery pack. Initiative have been made for the indigenous production of fuel cell power system in the country. There is a widespread use of fuel cell power generation, transport including other application. This will reduce dependence on scarce fossil fuels and help in preserving the environment.

 

Achievements

·         Indigenous research and industrial bases have been established

·         R & D projects lead to technology/process/material development

·         Prototypes of proton exchange membrane fuel cells (PEMFCs) lad phosphoric acid fuel cells (PAFCs) have been developed

·         The application of fuel cells have been demonstrated for distributed power generation and vehicular propulsion

·         UNDP/GEF-assisted project on Fuel Cell Bus Development in India is under implementation

 

Potential Applications of Fuel Cells

·         Production of electricity, water and heat (or various end uses)

·         Industrial uses

·         Surface transportation

·         Residential applications   

·         Power supplies for personal computers, hospitals, health clinics, etc.

·         Electrification of remote locations/villages

 

GEOTHERMAL ENERGY

Water heated to steam beneath the crust of Earth can be harnessed to drive turbines for the generation of electricity. India has at Manikeran at Himachal Predesh and Tatapani in Madhya Pradesh. The Tatapani site is not suitable for generation of electricity as the temperature is low which is around \[{{90}^{o}}C\] while other two sites have temperatures upto \[130{}^\circ C\].

Existing geothermal resources, can be used for power generation. It ran be used as a source of heat for space heating, greenhouse cultivation, cooking, etc. Geothermal energy has the potential to effectively meet, he energy requirements of the people. There is a detailed report that is being prepared for the assessment of geothermal resource potential for direct heat applications and power generation. Similarly, magneto-telluric investigations to delineate sub-surface, geo-electric structure and evaluate by geothermal significance are being carried out in Tattapani geothermal area (Madhya Pradesh). Similar investigations have been made for Puga geothermal area.

 

Objectives

·         Harnessing of geothermal potential for direct heat applications and for power generation at promising geothermal sites

 

Activities

·         Field studies/surveys for geothermal resource assessment

·         Infrastructure development

·         Demonstration

·         Training and manpower development.

 

Thrust Areas

·         Creation of geothermal related data base and infrastructure for the indigenous production of geothermal power plants, equipment for deeper drilling of bore holes, etc.

·         Geothermal resource and manpower development

·         Applications of geothermal energy for power generation in domestic, agricultural and industrial sectors.

 

Achievements

·         Geothermal Atlas of India, prepared by the Geological Survey of India (GSI) gives information/data about more than 300 geothermal potential sites. This atlas is being updated by the GSI with MNES support.

·         Applications of geothermal energy are being demonstrated for small- scale power generation and thermal applications.

 

Potential Applications

·         Power generation

·         Cooking

·         Space heating

·         Use in greenhouse cultivation

·         Crop drying

Organisations working in geothermal energy

·         Central Electricity Authority

·         Geological Survey of India

·         Indian Institute of Technology, Mumbai

·         Regional Research Laboratory, Jammu

·         National Geophysical Research Institute, Hyderabad

·         Oil and Natural Gas Corporation, Dehradun

 

ENERGY FROM URBAN AND INDUSTRIAL WASTES

The huge growth in the quantum and diversity of waste materials generated by human activity has led to an increased awareness, worldwide. There is an urgent need to adopt efficient, scientific and safe methods for the treating processing and disposing various types of wastes.

·         Newer technologies are being employed for the recovery of energy from wastes. This not only reduces the quantity but also improves the quality of waste in order to meet the required pollution control standards.

·         An estimated potential about 1000 MW of power from urban and municipal wastes and about 700 MW from industrial wastes can be generated. This is likely to augment further with economic development.                                               

·         The Ministry of Non-Conventional Energy Sources has identified "Energy Recovery from Wastes" as one of its thrust area activities and is implementing following two programmes for recovery of energy from urban and industrial wastes.

v  National Programme on Energy Recovery from Urban and Industrial wastes

v  UNDP/GEF project on 'Development of High Rate Bio-methanation Processes'.

 

NATIONAL PROGRAMME ON ENERGY RECOVERY FROM URBAN AND INDUSTRIAL WASTES

·         It was launched in the year 1995-96.

·         There is a provision for various fiscal and financial incentives under this programme whose main objective are as follows:

·         To create appropriate environment with financial and fiscal regime to help promote, develop and demonstrate the utilization of wastes for generating energy

·         To improve the waste management practices through adoption of renewable energy technologies used in processing and treatment of wastes prior to disposal

·         To promote setting up of projects for recovery of energy from Urban and Industrial wastes.

 

Installation

·         15 Waste-to-Energy projects of an aggregate capacity of about 17.00 MW including those projects taken up under UNDP/GEF assisted project on High Rate Biomethanation Process, have already been installed. There are seven projects of combined capacity of about 12 MWe under installation. There is a proposal for ten more Waste-to-Energy projects of a total capacity of about 60 MWe which is under development.

 

MAGNETO HYDRO DYNAMICS (MHD)

It is not a non-conventional source. It is the science that deals with the phenomena arising from the motion of electrically conducting fluids in the presence of electric and magnetic field. It is a method of direct conversion of thermal energy into electricity without any moving parts. In this system air is heated to very high temperatures. High speed gases are ionised and are electrically conducted. When the ionised gases are made to flow over a magnetic field, it leads to the flow of electrons resulting in the generation of electricity. The thermal conversion efficiency of MHD is about 60% as compared to 30-35% in case of conventional thermal plant.

The MHD has its application in the areas like

(1) Development of fusion reactors.

(2) Simulation of hypersonic flight condition.

(3) Space vehicle braking upon re-entry to the atmosphere.

A prototype MHD power plant is set up by BHEL and BARC jointly at Trichy in Tamil Nadu. It has been established with technical and financial assistance from former Soviet Union. This has been set up to design a larger MHD plant. Trichy plant is sponsored by DNGS.

 

FUEL CELL

Fuel cell is an electrochemical energy conversion device, which produces energy in the form of electricity and heat as long as fuel is supplied. A fuel cell consists of two electrodes sandwiched around an electrolyte. Oxygen passes over one electrode and hydrogen over the other, generating electricity, water and heat. In principle, a fuel cell operates like a battery but unlike a battery, a fuel cell does not run down or require recharging. Hydrogen fuel is fed into the 'anode' of the fuel cell. Oxygen (or air) enters fuel cell through the cathode. In the presence of a catalyst, the hydrogen atom splits into a proton and electron, which take different paths to the cathode. The proton passes through the electrolyte. The electrons create electric current and return to the cathode, to be reunited with hydrogen and oxygen in a molecule of water.

A fuel cell system which includes a 'fuel reformer' can utilise the hydrogen from any hydrocarbon fuel like natural gas to form methanol and even gasoline.

 

What are the different types of fuel cells?

Fuel cells are a family of technologies. Fuel cell types are chracterised by their electrolytes and temperature of operation.

(1) Phosphoric acid fuel cell

(2) Proton exchange membrane or solid polymer types

(3) Molten carbonate type

(4) Solid oxide type

(5) Alkaline

(6) Direct methanol fuel cell

(7) Regenerative fuel cell

(8) Zinc air fuel cell

(9) Protonic ceramic fuel cell

 

CFL

What is a CFL?

A CFL (Compact Fluorescent Light) is also known as compact fluorescent light bulb or an energy saving light bulb. It is a type of fluorescent lamp that screws into a standard light bulb socket. (That's why compact).

 

How does a CFL work?

A CFL has two parts:

(1) Gas filled tube (or bulb)

(2) Magnetic/electronic ballast

The electricity flows through the ballast. The electrical energy from the ballast flows through the gas causing it to give off Ultraviolet Light (UV Light.

The ultraviolet light then excites the white phosphor coating on the inside of the tube. This excited white phosphor coating emits visible light.

 

Why are CFL-s more advantageous than filament bulbs?

·         CFL's have longer life.

·         CFL use less electricity.

·         In the long run CFL is more economic than bulb.

·         The production and recycling of CFL is more eco-friendly than that of bulbs.

·         The barrier to usage of CFL is its initial high cost.

·         Many Governments are now encouraging use of CFI?s by promoting its advantages.