• Non-conventional(renewable) energy, are sources that are continuously replenished by natural processes. Most of the renewable energy comes directly or indirectly from sun or wind and never get Renewable energy sources are essentially flows of energy, whereas fossil and nuclear fuels are in essence, stocks of energy.


  • Generation and consumption of energy from non-conventional energy source causes minimal or no degradation of
  • Practically inexhaustible and easily available in nature
  • The energy plants for tapping these non-conventional energy sources are suitable to be set up peripherally in remote areas whereas setting up of conventional sources of energy plants is extremely
  • Non-conventional source of energy are therefore exploited in a decentralised manner generating local
  • The installation cost is high but maintenance and running costs of such plants is very cost effective in longer
  • Gestation period is short and these plants yield quick


  • They are subject to influence of natural forces and therefore their availability varies from day to night and also from season that is these plants cannot provide a steady continuous supply of energy.
  • Initial investment cost is high and at present technological development stage it is not very cost

Different types of NC sources of energy:

  • Solar Energy
  • Wind Energy
  • Wave Energy
  • Tidal Energy
  • Ocean Thermal Energy Conversion (OTEC)
  • Geothermal Energy
  • Bio-Energy


  • It refers to the energy collected from the sunlight which is an inexhaustible, clear and basic source of all other energy. It provides energy by the process of nuclear fusion. Solar Energy can be utilised through two different routes such as
  • Solar thermal route(solar energy is converted to thermal energy with the help of devices such as solar water heaters and solar cookers etc)
  • Solar photovoltaic route or solar electric route (made of semiconductor silicon convert solar energy into electrical energy)
  • The largest solar power plant is being constructed in Thardesent in Jaisalmer in Rajastan. The largest solar pond is in Bhuj, Gujarat.


  • It is basically harnessing of wind power to produce electricity. The Kinetic energy of the wind is converted into electrical energy using wind turbines. In wind mills, wind energy is used directly as mechanical energy for pumping water or grinding grains. Gross Wind power potential in India is about 45,000 MW. The favourable sites for harnessing electricity from wind energy have been located all thru out the coastal region in the including Gujarat, Konkan, Southern Tamil Nadu, Orissa and WB Asia’s largest wind form is located at Mupandal in Tamil Nadu. India is ranked 5th after China, Germany, USA & Spain in terms of energy generation by exploiting wind energy resources. An average wind speed of 25 km / hour is required to produce good quality of


  • Ocean covers more than 70% of earth surface making the world’s largest solar collectors. Ocean energy draws on the energy of ocean waves, tides or on the thermal energy stored in the ocean.


  • Wave energy technologies generate electricity from the undulating motion of the ocean waves. The power in the moving wave may drive a turbine or device directly or it may pressurise air or hydraulic fluid. Ocean Engineering Cell, IIT Chennai has established 150 KW pilot project at Vizhinjam harbour and Thangassery in Kerala. It has to establish 5 pilot project at Mus Point in Kar- nicobar in Andaman & Nicobar Islands.


  • Tidal energy is caused by gravitational forces of Sun and Moon. It is a form of hydropower that converts energy of tides into electricity. Its potential is 8000- 9000 MW. A barrage or dam is typically used to convert tidal energy into electricity by forcing

the  water  through  turbines activating  a  generator.  The central  electricity  authority  of India has identified Gulf of Kutch &Kambay  and  Sunderban  coast in  West  Bengal  as  favourable locations  with  necessary  tidal range to  harness  tidal  energy. India  is  seeking  technical assistance from France which is a world  leader in  harnessing  tidal energy  and  has  also  successfully established  a  240MW  tidal energy  plant  at  a  place  called  La Rance.


  • It makes use of temperature difference created between warm water at the surface of ocean and water at its depth. This temperature gradient is of the range of about 10°C is sufficient to vaporise volatile substances like ammonia, propane etc. In OTEC plant hot surface water acts as a heat source vaporising the volatile substances in their vapour forms help in running turbines – activates a generator to

produce  electricity.  The  best location  for  establishing  OTEC plants  are  situated  along  the coast  of  Tamil  Nadu,  Andaman Nicobar Islands and Lakshadweep.  An  OTEC  project cell  of  IIT  Chennai  has established  1MW  pilot  project each  at  2 places in Kavaratti and Minicar  Islands  at  Lakshadweep. The  sea  solar  power  corporation of  USA  has  entered  into commercial  agreement  with Tamil  Nadu  Government establishment.        It’s first operational   plant at KulasekarPattinam.


  • It is found trapped in Earth’s crust at a depth of 10 km in the form of hot springs, geysers etc. The geothermal potential of India is primarily located along the Himalayas about 250 hot springs at a temp range of 90-130oC have been identified at places like, Puga Valley in Ladakh, Manikaran in Himachala Pradesh &Tattapani in Chhattisgarh. National Aerospace Laboratory

Bangalore has set up a pilot project in Manikaran for R&D and for collecting operational data to design larger geothermal power plant.


  • Under bio-energy, biomass is regarded as the potential source of renewable energy. (Biomass refers to the organic biodegradable waste of animal and plant origin). It is derived from numerous sources including the by-products from the wood industry, agri crops, raw materials from the forest, household waste, cow dung etc. It is mainly rich in carbohydrates like starch & cellulose and also contains varying amount of nitrogen and phosphorous. Biomass offers clean fuel or energy in the form of
  • Biogas is a clean and efficient fuel generated from cow dung, human waste or any kind of bio- degradable material derived through anaerobic fermentation. Bio gas is mainly Methane (55- 65%) & CO2 (35% – 40%). It is a versatile fuel used for the purpose of cooking, lighting, even for running diesel pumpsets at low cost. The organic waste extracted from biogas plant is said to be rich in phosphorous and potassium and can be very effectively used as manure. It has high calorific value, low ash content, absence of polluting gases like sulphur, eliminate the need for pollution control equipment, ease of handling and transportation and storage. Bio energy in the form of biogas is expected to become one of the key energy resources for global sustainable development.
  • The potential of biomass power in India is estimated at about 19,500 MW. The National Biogas Programme was initiated in 1981- 82  for  the  promotion  of  family size biogas plants with the aim of providing  a  clean  and  cheap source  of  energy  along  other benefits  such  as  enriched manure,  improved  sanitation, hygiene  and  reduction  in drudgery  for  women.  Centre  is even  offering  50%  subsidy  thru states to set up biogas plants in rural areas.


  • These are the fuel,which are derived from non-crude oil sources such as bio alcohol (methanol, ethanol, and butanol), biodiesel, hydrogen fuel cell etc. They are renewable sources of energy available indigenously which hold a likely future. Alternate Fuels are both beneficial environmentally and economically.

5.12.1 Environmental Benefits

  • They are free from sulphur, so do not cause SO2
  • They burn  more Produce less carbon monoxide – is reduced by about 35%
  • They also reduce emission of hydrocarbons by almost about 55%
  • They have less particulate matter and the emission reduced in this case is 45%

5.12.2 Economic Benefits:

  • India at present imports 75% of crude oil requirements which are more than Rs.70,000crore annually. AF can be significant import substitution since they are renewable sources of energy. Their continuous demand can also help farmer to earn a steady income by cultivating plants from which they are

5.12.3 Demerits

  • These fuels are highly viscous so require high injection pressure when used in internal combustion engine.
  • These fuels are corrosive in nature. So are not very stable fuels.
  • Their persistant use leads to deposition of carbon in

5.12.4 Biodiesel

  • It is an alternative fuel derived from vegetable oils of Jatropha, Soyabean, Grapeseed, Mahua, Sunflower etc. The fruit of Jatropha plant – grows in poor soil – little water has been found suitable for the extraction of

biodiesel. Chemically bio-diesel is the methyl or ethyl ester of fatty acids obtained by the process of trans etherification.

Vegetable Oil + NaOH + Methand

  • Fatly acids + Methy Ester (FAME)
  • Ethanol blended Petrol
  • Ethanol is an alcohol extracted from molasses – is a by product in sugar industry is available three out India Blending of ethanol – petrol – enhance the burning properties of fuel leading to lower CO in

5.12.6 Hydrogen Fuel Cell

  • Fuel cells convert chemical energy into electrical energy, through an electro chemical process taking place in between fuel and an oxidant separated by an electrolyte. The chemical reaction goes on till the fuel cell is supplied with fuel and oxidiser from outside. Therefore fuel cell does not run down like batteries. The most common fuel is H2 and the oxidiser is O2.

5.12.7 Algae based fuel:

  • Algae requires nutrients, sunlight & water to grow, algae thrive on saline, brackish and waste waters. There have been proposals made where wastewater, human waste, animal waste & plant waste, along with CO2 emissions from industrial processes can all be used as the nutrients in algaculture. In regards to the monoculture production of algae, wastewater, human waste, animal waste & plant waste, along with CO2 emissions from industrial process’s, would have to be all transported or pumped to arid area algaculture farms. After oil is extracted from the algae the algae residue is then used as an animal feedstock or as a soil
  • The lipid, or oily part of the algae biomass can then be extracted and converted into biodiesel through a process similar to that used for any other vegetable oil, or converted in a refinery into “drop-in” replacements for petroleum-based fuels. The algae’s carbohydrate content can

be fermented into bioethanol and biobutanol.

  • Algae bio fuels could yield more than 2000 gallon of fuel / year of production. They are being successfully tested by US


  1. What is frequency modulation? (90/II/8a(C)/3)
  2. What do you understand by nuclear fall out? What is its harmful effects? (90/II/8b(C)/3)
  3. What is a fast breeder reactor? Discuss briefly its role in India’s nuclear energy programme. (92/II/7b/20)
  4. What is heavy water? What is it used for? (92/II/8a(C)/3)
  5. What is RDX made of? Why has it been in the news lately? (93/II/7d/20)
  6. Describe briefly the different phases of India’s nuclear energy programme. (94/II/7a/20)
  7. What is nuclear medicine? Describe briefly its different uses. (96/II/7a/20)
  8. Where are the following located? (96/II/8f(C)/3)

(Give the name of the city and state)

  • Central Drug Research Institute
  • Space Applications Centre
  • India Gandhi Centre for Atomic Research. (96/II/8f(C)/3)
  1. How has India’s Nuclear Programme contributed to the economic and defence requirements of the country? (About 250 words) (97/II/3b/40)
  • What is a fast breeder reactor? Comment on its suitability in the Indian context. (About 250 words) (99/II/3b/40)
  1. What is carbon dating? Describe its applications in archaecology. (99/II/7b/20)
  2. What do the INMAS stand for? (99/II/10d(iii)/1)
  3. Where is Indiran Gandhi Centre for Atomic Research located? (99/II/10e(ii)/1)
  4. Write about Radiation and its effects. (03/1/13b/2)
  5. Discuss in detail “Alternative Energy Sources”. (04/II/10a/30)
  6. Why is hydrogen being acclaimed as the fuel of the

future?  (About  150  words) (05/II/11c/15)

  1. What are the alternative fuels available for the transport sector? Discuss their characteristics, advantages and disadvantages in their utilization. (07/II/11a/15)
  • Write brief note in about 30 words: Artificial (09/II/10a/3)
  1. Comment on the salient features of the Integrated Energy Policy recently approved by the Government and its implications on the energy security needs of the country. (09/I/8a/30)
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