ENERGY RESOURCES

Energy can be found in a number of different forms viz. heat (thermal), light (radiant),
mechanical, electrical, chemical, and nuclear energy.
There are two types of energy i.e. potential or stored energy and kinetic or moving or working
energy.
The potential energy is the energy of position and kinetic energy is energy of motion. Energy can
be transformed into another sort of energy. But it cannot be created and nor be destroyed. Energy
has always existed in one form or another.
The energy sources are divided mainly into two groups: renewable and non-renewable.
Renewable and non-renewable energy sources can be used to produce secondary energy sources
including electricity and heat. There are several units to measure energy viz. British thermal unit
(Btu), joules, calories, kilo watt hour (kWh).

GROWING ENERGY NEEDS

Energy is essential to the existence of mankind. All industrial processes like mining, transport,
lighting, heating and cooling in buildings need energy. With the growing population, the world is
facing an energy deficit. Lifestyle change from simple to a complex and luxurious lifestyle adds
to this energy deficit. As per International Energy Agency (IEA), a 37% increase in global
primary energy demand is expected by 2040. Electricity demand is increasing twice as fast as
overall energy use and is likely to rise by more than two-thirds from 2011 to 2035. Almost 95%
of commercial energy is available from fossil fuels like coal and natural gas. These fossil fuels
will not last for more than a few years as is the scenario of growing energy utilization. Hence, we
must explore alternative fuel/energy options.

CAUSES OF GROWING ENERGY NEEDS

1. Urbanization: Developing countries are also being confronted with the global problem of
rapid urbanization, as most of their rural populations flock to cities.
2. Population explosion: Due to population explosion, the demand for energy has increased
many folds.
3. Industrialization: Businesses and factories in particular, require significant amounts of
energy in the form of both electricity and petroleum-based fuels in order to operate. As
economies industrialize, energy demand increases.
4. Increasing wealth in emerging markets: When economies grow, their energy needs also
grow. Consumers want cars, air conditioners, refrigerators, and other energy consuming
devices.
5. Globalization: As we move more often, and with greater speed, the energy we use in
transportation will inevitably increase. Air travel in particular is a heavy user of fuel.

WAYS TO MITIGATE GROWING ENERGY DEMANDS

The worldwide increase in demand for energy has put ever-increasing pressure on
identifying and implementing ways to save energy. In fact, the world has consistently improved
its energy efficiency. However, going forward the world will need even more improved energy
efficiency measures. These are mentioned below.
 1. More efficient buildings : Reflective roofing, better use of daylight, and other green and
energy-friendly improvements can drastically reduce energy demands from electricity-
guzzling commercial buildings.
2. Energy efficient light bulbs: Each $2 spent on new compact fluorescent lamps (CFLs)
can save more than $30 in power and replacement costs. Use of LED (light-emitting
diode) bulbs can further reduce the power and replacement expenditures.
3. Demand-side management (DSM): As electricity becomes more expensive, consumers
and utilities will have a mutual interest in finding new ways to manage demand for
electricity so as to reduce the cost to the end-user. For example, programs to turn off idle
appliances, rather than let them "sleep" in low-power mode, or to automatically turn off
the heat or air conditioner during the wee hours of the night in corporate headquarters.
4. Fuel efficiency: There are many other ways to improve fuel efficiency. One of the most
evident involves ensuring proper inflation of tires of the vehicles. Another method is to
limit frequent and intense stopping and starting, and other fuel-intensive driving
activities.

NON-RENEWABLE ENERGY RESOURCES

Non-renewable energy resources have accumulated in nature over a long span of time
and cannot be quickly replenished when exhausted e.g. coal, petroleum, natural gas and nuclear
fuels like uranium and thorium. Coal, oil and natural gas are called "fossil fuels".

COAL
Coal was formed 255-350 million years ago when the ancient plants were buried after the death
into the soil and due to heat and pressure gradually got converted into peat and coal over millions
of years. Coal is a hard, black coloured rock-like substance. There are three main types of coal :
anthracite, bituminous and lignite. Anthracite coal is the hardest and has more carbon, which
gives it higher energy content. Coal is most abundant fossil fuel in the world. Major coal fields in
India are Ranighanj, Jharia, Bokaro, Singrauli and Godavari valley. Anthracite coal occurs only
in Jammu and Kashmir.

Following are the most significant uses of coal.

1. Electricity generation, steel production, cement manufacturing and as a liquid fuel.
2. Steam coal - also known as thermal coal - is mainly used in power generation.
3. Coking coal - also known as metallurgical coal - is mainly used in steel production.

PETROLEUM
Petroleum is often called as crude oil or oil. It was formed when the plants and animals died,
sank to the bottom of the oceans and were buried by thousands of feet of sand and silt. The heat
and pressure changed the remains, and eventually, petroleum was formed.
Petroleum deposits are locked in porous rocks almost like water is trapped in a wet sponge.
When crude oil comes out of the ground, it can be as thin as gasoline or as thick as tar. Hence it
has to be purified and refined by the process of fractional distillation, during the process different
constituents separate out at different temperatures. Large varieties of products obtained from the
process are petroleum gas, paraffin wax, kerosene, petrol, diesel, fuel oil, lubricating oil, asphalt,
plastic etc.
 Oil fields in India are located at Digboi (Assam), Gujarat Plains and Bombay high,
offshore areas in deltaic coasts of Godavari, Krishna, Kaveri, and Mahanadi.

Petroleum is used widely in:

1. Transportation for running the vehicles,
2. In power stations where diesel is used to produce electricity,
3. For domestic and lightning purposes in which kerosene is used,
4. For the construction of metal roads, in which tar is used,
5. For the manufacturing of candles and pharmaceuticals in which paraffin and vaseline are used.

NATURAL GAS
Raw natural gas is a mixture of different gases. Natural gas can be hard to find since it is usually
trapped in porous rocks deep underground. Natural gas is highly flammable. It is mainly
composed of methane (95%) with small amount of propane and ethane. Methane is odourless,
colourless and tasteless. As a safety measure, natural gas companies add a chemical odourant
called mercaptan to detect escaping of gas.

Various uses of natural gas are as follows.

1. It is commonly used to heat and cool homes and businesses worldwide.
2. It is also used as a fuel in Thermal power plants for generating electricity.
3. It is used as a source of hydrogen gas in fertilizer industry and as a source of carbon in tire
industry.

RENEWABLE ENERGY RESOURCES

Renewable energy resources can be replenished in a short period of time, can be
generated continuously in nature and are inexhaustible e.g. solar energy, wind energy, tidal
energy, hydropower, biomass energy, biofuels, geothermal energy and hydrogen. They are also
known as non-conventional source of energy and they can be used again and again in an endless
manner.

SOLAR ENERGY

Solar energy is radiant energy that is produced by the Sun. Every day sun radiates enormous
amount of energy. The solar energy comes from within the Sun. The hydrogen atoms in the
Sun's core form helium by nuclear fusion and generate enormous energy. Traditionally, solar
energy was used as energy source for drying clothes and food grain, preservation of eatables and
for obtaining salt from sea water for thousands of years, but recent development in technology
made possible to use it for generating power.
Some important solar energy harvesting devices are solar cell, solar cooker, solar water heater,
etc.

Advantages of Solar Energy

1. It is a source of free energy, needs no fuel and produces no waste or pollution.
2. In sunny countries, solar power can be used and is a boon for those regions where
electricity supply does not exist.
 3. Solar energy is handy for low-power uses such as solar powered garden lights and battery
chargers, and reduces energy bills.

Disadvantages of Solar Energy

1. It doesn't work at night and during cloudy weather.
2. Solar power stations are very expensive to build. Solar cells cost a great deal compared to
the amount of electricity they will produce in their lifetime.
3. It can be reliable only in a very sunny climate.

WIND ENERGY
Wind energy is the kinetic energy associated with the movement of atmospheric air.
Wind energy has been used for hundreds of years for sailing, grinding grain, and for irrigation.
Wind energy systems convert this kinetic energy to more useful forms of power. Wind energy
continues to be the fastest growing renewable energy source with worldwide wind power
installed capacity reaching 14,000 MW. In India, the states of Tamil Nadu and
Gujarat lead in the field of wind energy.

Some of the gadgets are Windmills, and Wind turbines.

Wind mills: The Sun heats the atmosphere unevenly, so some patches become warmer than
others. These warm patches of air rise and other air patch blows to fill the space. The energy in
the wind can be used by building a tall tower, with a large blade/propeller on the top. The wind
blows the propeller in a circle, which turns the generator to produce electricity.
Wind turbines: These transform the wind energy into mechanical power, which can then be
used directly for grinding etc. or further converting to electric power to generate electricity.
Today's wind machines use blades to collect the wind's kinetic energy.
The blades are connected to a drive shaft that turns an electric generator to produce electricity.

Advantages of wind energy

1. Wind is free, wind farms need no fuel.
2. Produces no waste and greenhouse gases.
3. The land beneath can still be used for farming.
4. Wind farms can be tourist attractions.
5. Good method of supplying energy to remote areas.

Disadvantages of wind energy

1. The wind is not always predictable.
2. Suitable areas for wind farms are often near the coast, where land is expensive.
3. Some people feel that covering the landscape with these towers is unattractive.
4. It can kill birds; migrating flocks tend to like strong winds.
5. It can affect television reception.
6. It can be noisy. Wind generators have a reputation for making a constant, low,
"swooshing" noise day and night.
 HYDROELECTRIC ENERGY
The name comes from "hydro", the Greek word for water. Hydroelectricity is electricity
generated by hydropower, i.e., the production of power through use of the gravitational force of
falling or flowing water. For production of electricity from water, a dam is built to trap water,
usually in a valley where there is an existing lake. When water fall from a great height at the
turbines, it drives turbine and the connecting generator start the electricity generation.

Advantages of hydroelectric energy

1. Once the dam is built, the energy is virtually free.
2. No waste or pollution produced.
3. Much more reliable than wind, solar or wave power.
4. Electricity can be generated constantly.

Disadvantages of hydroelectric energy

1. The dams are very expensive to build. However, many dams are also used for flood
control or irrigation, so building costs can be shared.
2. Building a large dam will flood a very large area upstream, causing problems for animals
that used to live there.
3. Finding a suitable site can be difficult, sometimes the impact on residents and the
environment may be unacceptable.
4. Water quality and quantity downstream can be affected, which can have an impact on
aquatic and terrestrial life.

TIDAL ENERGY
The tide moves a huge amount of water twice each day, and harnessing it could provide a great
deal of energy. Tidal energy is the utilization of the Sun and Moon's gravitational forces - as
tides are formed by the gravitational pull of the Sun and Moon on the oceans of the rotating
earth. Tides can be found with varying degrees of strength on any coastline, and sometimes even
at sea, although these are better known as currents.
Globally, only four countries are generating power through tidal energy. The first country to start
generating electricity using tidal energy was
The other places where tidal power is used to generate electricity include Canada (20 MW),
China (3.2 MW) and Russia (0.4 MW).

Advantages of Tidal energy

1. Once power plant built, tidal power is free.
2. It produces no greenhouse gas and other waste.
3. It needs no fuel.
4. It produces electricity reliably.
5. Not expensive to maintain.
6. Tides are totally predictable.

Disadvantages of Tidal energy

1. A barrage across an estuary is very expensive to build, and affects a very wide area. Only
provides power for around 10 hours each day, when the tide is actually moving in or out.
 2. Damages like reduced flushing and erosion can change the vegetation of the area and
disrupt the balance.
3. The alteration of tidal currents affects the habitat of the seabirds and the fish.
4. Tidal energy is only available in a small number of regions. This depends on local
features.

GEOTHERMAL ENERGY
The word geothermal comes from the Greek words geo (earth) and therme (heat).
Geothermal energy is a renewable energy source and refers to heat energy generated and stored
inside the Earth. Most of this heat is provided from the decay of radioactive isotopes.
This deep geothermal energy can only be accessed when it arrives at the Earth's surface through
geological processes such as through fault lines on the Earth's crust (or areas of volcanic activity)
or by drilling through the surface to access it. Geothermal energy can sometimes find its way to
the surface in the form of volcanoes, hot springs and geysers.

The first geothermal power station was built at Landrello, in Italy, and the second was at
Wairekei in New Zealand.

Advantages of Geothermal energy

1. Geothermal energy does not produce any pollution, and does not contribute to the
greenhouse effect.
2. The power stations do not cover much area, so there is not much impact on the
environment.
3. No fuel is needed.
4. Once a geothermal power station built, the energy is almost free. It may need a little
energy to run a pump, but this can be taken from the energy being generated.

Disadvantages of Geothermal energy

1. There are not many places to build a geothermal power station.
2. The type of rock above is also important; it must be of a type that can be drilled easily.
3. Sometimes a geothermal site may "run out of steam", perhaps for decades.
4. Hazardous gases and minerals may come up from underground, and can be difficult to
safely dispose of.

BIOMASS ENERGY
Biomass is the organic matter produced by the plants or animals which include wood, crop
residues, cattle dung, manure, slaughterhouse waste, sewage, agricultural waste etc.
"Bioconversion" uses plant and animal wastes to produce "biofuels" such as ethanol, biogas and
oil.
Types of Biomass Energy
1. Energy Plantation
Solar energy is trapped by green plants through photosynthesis and converted into biomass. They
may produce energy either by burning directly or by getting converted into biogas or may be
converted into ethanol by fermentation.
2. Petro crops
Petro crops are those plants which are used for production of biodiesel from their fruits/seeds e.g.
jatropha, pongamia and oil palms.
3. Agriculture and urban waste biomass
Crop residues, wheat and rice straw, bagasse (sugarcane residues), coconut shells, peanut hulls,
cotton stalks etc. are some of the agricultural wastes which can be used to produce energy by
burning or fermenting. Animal dung, fishery, poultry waste and even human refuse are examples
of biomass energy.
4. Biogas
Biogas is a clean fuel produced through anaerobic digestion of several organic wastes like
agricultural, animal, domestic and industrial. It is relatively clean burning and colourless gas, and
composed of methane (CH4), carbon dioxide (CO2), and some traces of nitrogen (N2), ammonia
(NH3), sulfur dioxide (SO2), hydrogen sulfide (H2S), and hydrogen (H2), depending on the
feedstock used.
Biogas is produced in the anaerobic environment, where certain bacteria decompose organic
material. The whole process is referred as anaerobic digestion (AD). AD effectively treats the
organic fraction of waste. The process not only leads to a healthy and clean environment, but
also produces a renewable energy like methane. The by-product produced during the process is
high-grade manure.
In a biogas plant, biomass like vegetable wastes, animal excreta, and weeds undergo
decomposition in the absence of oxygen and form a mixture of gases.

Benefits of Biogas Plants

1. A non-polluting and renewable source of energy is created in biogas plants.
2. It is an excellent way of energy conversion.
3. Biogas plants produce enriched organic manure which can be used as fertilizers.
4. Biogas generated from organic waste provides improvement in the environment,
sanitation and hygiene.
5. The biogas plants provide a source for decentralized power generation.
Disadvantages of biogas plants
1. Low production during winter months
2. Low methane content
3. High retention time

USE OF ALTERNATE ENERGY SOURCES

Benefits of alternate / renewable energy resources
1. Environmental cleanness without pollutant emission
2. Non-depletive or renewable in nature
3. Availability throughout the world, provides energy security
4. Do not cause global warming
5. Waste reduction and also reduces the demand of land-fill sites
6. Stabilization of energy costs
7. Provide stability in oil price