Besides solar, wind and biomass, there are other eco-friendly and renewable sources
from which energy can be tapped for varied applications. MNES is sponsoring various
R&D programmes to develop the technologies for exploitation of above sources. These
- Chemical Sources of Energy Fuel
- Hydrogen Energy
- Alternative Fuel for Surface Transportationâ€”Battery
- Geothermal Energy
- Ocean and Tidal Energy
Fuel cell is an electrochemical device that converts the chemical energy of a fuel
directly and very effectively into electricity (DC) and heat, without combustion.
The most suitable fuel for such cells is hydrogen or a mixture of compounds containing
hydrogen. A fuel cell consists of an electrolyte sandwiched between two electrodes.
Oxygen passes over one electrode and hydrogen over the other, and they react electrochemically
to generate electricity, water, and heat.
Fuel cells are capable of converting 40% of the available fuel to electricity. This
can be raised to 80% with heat recovery. The fuel cell has no moving parts, therefore
it is highly reliable source of energy.
Fuel cell system efficiency is independent of the rated power above 100 kW, unlike
oil, gas or coal burning power plants, where the efficiency is constant only at
the megawatt power level. Even at the 40% of the rated load, a fuel cell has almost
the same efficiency as that of the full load. They are also able to respond in fast
load changes, because the electricity is generated by a chemical reaction and are
eco-friendly with little or no air pollution.
Fuel cells are classified primarily by the kind of electrolyte they employ. This
determines the kind of chemical reactions that take place in the cell, the kind
of catalysts required, the temperature range in which the cell operates, the fuel
required, and other factors. These characteristics, in turn, affect the applications
for which these cells are most suitable. There are several types of fuel cells currently
under development, each with its own advantages, limitations, and potential applications.
A few of the most promising types include
- Proton Exchange Membrane (PEM)
- Phosphoric Acid (PAFC)
- Solid Oxide (SOFC)
- Alkaline (AFC)
- Direct Methanol (FMFC)
- Molten Carbonate (MCFC)
Hydrogen can be used to combine with the oxygen in the air, converting it into water
while producing the heat and electricity. It is like a battery, except that a fuel
cell does not run down or require recharging like a battery. It recharges itself
while you are drawing power. Hydrogen is commonly available in fuels like propane
and natural gas. Fuels that contain hydrogen include:
- Natural gas
- Diesel fuel
Hydrogen energy is a clean and abundant energy source. When used in a fuel cell,
the only emission created is water - no burning or combustion therefore no pollutants.
The water can be electrolyzed to make more hydrogen which supplies more fuel.
Hydrocarbons, water and oxygen are processed through a fuel processor (also called
a reformer) to produce hydrogen, carbon dioxide and carbon monoxide.
Water is added and carbon monoxide is converted to carbon dioxide plus hydrogen.
The hydrogen produced is then ready for conversion in the fuel cell itself which
consists mainly of two electrodes, the negative anode and the positive cathode,
separated by an electrolyte - in this case a polymer electrolyte membrane (PEM).
The electrodes are coated on one side with a catalyst that helps the process. The
catalyst is a special material that facilitates the reaction of oxygen and hydrogen.
Pressurized hydrogen fuel enters the anode side and air enters the cathode side.
Helped by the catalyst, the hydrogen molecule splits into two protons and two electrons.
The hydrogen has a negative and positive charge like a battery, As the hydrogen
molecules enter the negative electrode, they split in two forming protons and electrons.
The hydrogen enters the fuel cell where the electrons (negative charge) flow out
of the fuel cell as electricity. The protons (positive charge) travel across the
PEM and combine with oxygen from the air. This chemical reaction creates molecules
of water that leave the fuel cell and generate heat from this process, as well as
supply the positive side needed to complete the electrical circuit.
Battery Operated Vehicles
Battery operated Vehicles run by an electric motor, powered by a pack of rechargeable
tract ion batteries positioned in the vehicle Itself. The power transmission takes
place through conventional gear box and differential gear box. The speed is controlled
by an Electronic Chopper Controller and gear changing. In all other respect such
as steering braking, gear box and clutch arrangements etc. Electravans are similar
to conventional diesel or petrol vehicles. Therefore they need no extra training
Optional battery withdrawal arrangement is provided with facilities for removal
of discharged batteries and fitting of charged ones within few minutes at the battery
In view of the obvious advantages of Electravans, Ministry of Non-conventional Energy
Sources, Government of India, gives a cash subsidy to the buyers. Electravan usage
is being increasingly favoured to fight the menace of air pollution in urban areas,
industries & institutions.
- Freedom from highly discomforting
noise & vibrations so common in diesel vehicles.
- Recurring savings of petrol or diesel.
- Ideal vehicle to keep environment
- Ideally suited as public transport
in congested areas, hospitals, factories, wild life sanctuaries, airport, schools
& places of historic Importance.
No engine related maintenance expenses & much lesser maintenance OPI chassis pails
due to absence of vibrations.
The Central Electrochemical Research Institute (CECRI), Karaikudi is developing
high-energy lithium polymer batteries of 1 ah capacity with a life cycle of 350
yrs for vehicular traction. CECRI has already synthesized and characterized LiCoO
cathode active material and completed the optimisation of polymer electrolyte films
and basic cell studies. The charge-discharge studies indicated cell efficiencies
of more than 60%
The project sanctioned at the Center for Materials for Electronics Technology (C-MET),
Pune, envisages the development of novel route synthesis, characterisation and electrochemical
studies on high quality cathode materials for rechargeable lithium batteries for
electric vehicle use. Lithium manganese oxide is one of the cathode materials for
lithium batteries. C-MET has developed cathode materials and characterised by using
different characterization techniques. Work is in progress for the development of
prototype lithium cells and for optimisation of various parameters
The Ministry of Non-conventioanl Energy Source is implementing a programme on battery
operated vehicles (BOVs) which includes battery operated passenger three wheeler
and battery operated passenger cars, besides battery operated buses through State
Nodal Agencies and Departments in the States and Union Territories. The programme
provided subsidy for the purchase of these types of indigenously manufactured vehicles.
Under this programme, a total of 21 BOVs were procured by different agencies through
State Nodal Agencies during 2004-2005. The existing programme of battery operated
vehicles has met its objectives and from fiscal 2005-06 will be replaced by the
hybrid vehicle programme.This programme provides subsidy for the following types
of Battery Operated Vehicles
- Central Subsidy is being provided
for ten and more seaters Battery Operated Buses/Mini buses @ 33 per cent of the
cost of vehicle (exclusive of excise duty, sales tax and all other levies) or Rs.3.50
lakh per vehicle;
- Eight and more seater Battery Operated
Passenger Three Wheelers @ 33 per cent of the cost of the vehicle (exclusive of
excise duty, sales tax and all other levies), or Rs.80,000 per vehicle; and
- Four seater Battery Operated Passenger
Cars @ 33 per cent of the cost of vehicle (exclusive of excise duty, sales tax and
all other levies), or Rs.75,000 per vehicle.
Geothermal energy is energy coming out of the molten interior of the earth towards
the surface. The average rate at which this heat emerges is about 0.05 W/m2, while
the radial temperature gradient which causes this heat flow is about 0.03oC per
metre. Thus, on an average, the temperature of the earth increases by 30oC per kilometer
as one move inwards.
Because of non-homogeneities in the earth's crust, there are numerous local hot
spots just below the surface where the temperature is in fact much higher than the
average value expected. Ground water comes into contact with the hot rocks in some
of these locations and as a result, either dry steam or wet steam and water are
formed. A well drilled to these locations causes the dry or wet steam to emerge
at the surface where it s energy can be utilized either for generating electricity
or for space heating.
The first commercial geothermal power station was erected in Larde-rello in Italy
in 1904. The capacity of the plant was increased in stages and was 406 MW in 1975.
Other locations where relatively large plants are operating are in The Geysers,
California, U.S.A. (600 MW) and in Wairakei, New Zealand (190 MW). The total installed
capacity in the world in 1975 was about 1500 MW.
This estimate indicates that about 62500 MW could be generated for a period of 50
years. The geothermal is the heat stored locally at depths of 1 or 2 km in the earth's
mantle in hot dry rocks with which water has not come into contact. Utilization
of these sources required development of techniques for artificial fracture of the
rocks, the injection of water into the fractures and subsequent recovery of the
steam for driving turbines.
In India, geothermal resources in the form of steam and hot water are known to exist
along the West Coast, in Ladakh, and in parts of Himachal Pradesh. However, no firm
estimates of their potential are available.
Ocean and tidal Energy
Tides are generated primarily by the gravitational attraction between the earth
and the moon. They arise twice a day. In mid-ocean, the tidal range is only a metre
or less, but in some coastal estuaries, it is much greater. This is due to the amplification
of the tidal wave as it moves up the narrowing channel of the estuary.
Basically, in a tidal power station, water at high tide is first trapped in an artificial
basin and then allowed to escape at low tide. The escaping water is used to drive
water turbines which in turn drive electrical generators.
Jeffreys has estimated that the rate of tidal energy dissipation for the world is
about 3X106 MW. However, only a small fraction of this can be exploited since, for
practical purposes, one needs a certain minimum difference of level between the
high and low tides. In addition, the geography of a location has to be suitable
from the point of view of the civil construction involved. Hubbert has compiled
the available information on favourable locations and the tidal power which can
be generated at each of them, and estimates that a maximum capacity of 63800 MW
can be harnessed. Some of the major sites are in the Bay of Fundy in North America,
in the White Sea in U.S.S.R., and in Mont Saint Michel in France.
The first commercial tidal power station in the world was constructed in France
in 1965 across the mouth of the La Rance Estuary. It has a capacity of 240 MW. The
average tidal range at La Rance is 8.4 m and the dam built across the estuary encloses
an area of 22 km2.
In India, tidal power could probably be generated in Kutch and in the Hooghly river.
In both these areas, an adequate head is known to exist. However, specific locations
have not been identified and estimates of the amount of power which could be generated
have to been made.
Wave energy arises because of the interaction of the winds with the surface of the
oceans. It could therefore be considered as one of the indirect ways of utilizing
solar energy. The energy available varies with the size and frequency of the waves.
However, on an average, it is estimated that about 10 kW are available for every
metre of wave front. Due to the wide fluctuations in frequency and amplitude at
any location, wave energy is difficult to collect from a practical standpoint. In
addition, devices built for the purpose have to transfer the collected energy ashore
and have to be strong enough to cope with adverse weather conditions. In spite of
these problems, research for utilizing wave energy is in progress in many countries
and many experimental devices have been built. If this research is eventually successful,
it is possible that these devices could help to meet the local needs of small coastal
Biofuels are fuels derived from biomass - recently living organisms or their metabolic
by-products. Agricultural products specifically grown for use as biofuels include
corn, sunflower and soybeans. In India, the physic nut (jatropha curcas) and the
Indian beech (pongamia pinnata) are favored for their drought resistance and ability
to grow in marginal soils, thereby reducing demand on arable soils needed for food
Biofuels are used as a direct replacement for energy and industrial fuels such as
HFO, or can be easily processed into biodiesel, an alternative to petroleum-based
Biodiesel is a renewable fuel that can replace petro diesel in current engine specifications
without alteration and can be transported and sold using existing infrastructure.
Biodiesel is non-flammable, and in contrast to petroleum diesel it is non-explosive,
with a flash point of 150Â°C for biodiesel as compared to 64Â°C for petro diesel.
Unlike petro diesel, it is biodegradable and non - toxic, and significantly reduces
toxic and other emissions when burned as a fuel.
Chemically, it is a comprised of a mix of mono-alkyl esters of long chain fatty
acids. A lipid transesterification production process is used to convert the base
vegetable oil to the desired esters and remove free fatty acids (de-gumming). The
most common form uses methanol as an additive to produce methyl esters, though ethanol
can be used to produce an ethyl ester biodiesel. A by-product of the transesterification
process is the production of glycerol, which is traditionally used in the cosmetics
and food industry.
After processing, unlike straight vegetable oil, biodiesel has very similar combustion
properties to petroleum diesel, and can replace it in most current uses. However,
it is most often used as an additive to petroleum diesel, improving the otherwise
low lubricity of pure ultra low sulphur petro diesel fuel.