Enery Resource

Nature of EnergyEnergy is all around you!– You can hear energy as sound.– You can see energy as light.– And you can feel it as wind

You use energy when you:– hit a softball.– lift your book bag.– compress a spring.Living organisms need energy for growth and movement

Energy is involved when:– a bird flies.– a bomb explodes.– rain falls from the sky.– electricity flows in a wire.

The five main forms of energy are:–Heat–Chemical– Electromagnetic–Nuclear–Mechanical

• Energy: Energy is the physical quantity, which can

manifest itself as heat, as mechanical work, as motion and in the binding of matter by nuclear or chemical forces.

(OR)Energy may be defined as "any property, which can be converted into work

(OR)Energy is defined as, "the capacity to do work."

The two laws of thermodynamics describe the behaviour of energy:First law :

It states that energy may be transformed from one form to the other, but cannot be created or destroyed.Second law:

It states that because some energy is always dispersed into unavailable heat energy, no spontaneous transformation of energy from one to other form (light to protoplasm, for example) is 100 per cent efficient.

Energy consumption is considered as an index of its development

The first form of energy known was FIREWind and Hydropower have been in use for the

last 10,000 yearsThe invention of steam engines replaced the

burning of wood by coal and coal was later replaced to a great extent by oil.

In 1970’s due to Iranian revolution and Arab oil embargo the prices of oil shoot up, leading to exploration and use of several alternate sources of energy

Growing Energy Needs

Per capita energy use and GNP• (Data from World Resources Institute, 1997)

Measurement of Energy / Units of EnergyAbbreviation Name

1) J Joule Standard SI Unit of Energy

2) BTU British Thermal Unit3) Cal Calories4) erg Erg5) KWh Kilowatt/hour6) MWd Megawatt/day

Energy sourceA source of energy is one that can provide adequate

amount of energy in a usable form over a long period of time

Classification of Energy Sources Renewable Energy Resources

Non-Renewable Energy Resources

Renewable Energy Resources – which can be generated continuously in nature and are

inexhaustible (also called as non-conventional energy sources)

e.g., wood, solar energy, wind energy, tidal energy, hydro power, bio-mass energy, bio-fuels, geo-thermal energy and hydrogen

WORLD ENERGY CONSUMPTION

RENEWABLE ENERGY RESOURCES (OR) NON-CONVENTIONAL ENERGY RESOURCES

Renewable energy resources are natural resources which can be regenerated continuously and are inexhaustible. They can be used again and again in an endless manner.

Ex: Wood, solar energy, wind energy, hydropower, tidal energy, etc.,

Merits of renewable energy resources Unlimited supply Provides energy security. Fits into sustainable development concept. Reliable and the devices are modular in size. Decentralized energy production.

Non-renewable energy resources (or) conventional energy sources

Non-renewable energy resources are natural resources, which cannot be regenerated once they are exhausted. They cannot be used again.

Ex: Coal, Petroleum, Natural Gas and Nuclear Fuels like Uranium Thorium… which have accumulated in nature over a long span of time and cannot be quickly replenished when exhausted.

SOLAR ENERGY:The energy that we get directly from the sun is

called solar energy. The nuclear fusion reactions occurring inside

the sun release enormous amount of energy in the form of heat and light. Several techniques are available for collecting, converting and using solar energy

The solar energy received by the near earth space is approx. 1.4kJ/m2-s (solar constant)

Traditional uses – drying clothes and food grains, preservation eatables, for obtaining salt from sea-water…

Techniques for harnessing Solar energy→ Solar Heat Collectors→ Solar Cells→ Solar Cookers→ Solar Water Heaters→ Solar Furnaces→ Solar Power Plants

Solar Cell (or) photovoltaic cells (or) PV cells

Solar cells are made of thin wafers of semi-conducting materials like silicon or gallium

When solar radiations fall on them, a potential difference is produced which causes the flow of electrons and produces electricity

The potential difference produced by a single PV cell of 4 cm2 size is about 0.4-0.5 volts and a current of 60 mA is produced

Solar Heat CollectorsThese can be passive or active in naturePassive heat collectors are natural materials

like stones, bricks…which absorb heat during day time and release it slowly at night

Active solar collectors pump a heat absorbing medium (air or water) through a small collector which is normally placed at top of the building

Solar cooker

WATER HEATER

Advantages of solar energy1. Solar energy is free and it is available locally in abundance.2. Solar energy is pollution free.3. Systems are easy to install, generate and maintain.4. System can be specifically designed according to individual

requirements.5. Supply of hot water is instant and un interrupted6. Recurring fuel costs are zero7. Heating 100 liters of water to 60o c by solar system results in

an energy saving of 1200-1500 units (kilowatts hours) of electricity per year.

WIND ENERGYMoving air is called wind.

Energy recovered from the force of the wind is called wind energy

The high energy winds have lot of energy in them as kinetic energy due to their motion

The driving force of winds is sun The wind energy is harnessed by

making use of wind mills The blades of the wind mill keep on

rotating continuously due to the force of the striking wind

The rotational motion of the blades drives a number of machines like water pumps, flour mills and electricity generators

WIND MILL High-speed winds (kinetic energy) have a great capacity

to generate power (electrical energy). Wind energy is inexhaustible, cost effective, and eco

friendly, non-polluting and freely available source of energy all over the day and night.

The instrument for harnessing wind power is called wind mill.

Small windmills are in use in rural areas for power generation, pumping water and other domestic purposes, particularly in the rural areas, such as threshing, winnowing, cutting wooden logs, grinding grain and pump water etc.

Wind energy can also be used for battery charging to run generators.

To generate electricity, the speed of wind should be from 10-20 km/hour, which is available on coast, mountain, certain valleys and plains

The force of wind rotates the wheel, which is connected to a generator or turbine for generation of electricity. It is a Fast growing technology.

Denmark, Spain, Germany USA and India are the leaders in wind energy development and more cover than 80 per cent of world capacity.

World Watch Institute (The Washington, USA) ranked India as a Wind Superpower.

Wind power development in India has been rapid at selected sites.

Muppandal (Tamil Nadu), has the highest concentration (400 MW) of wind farms in Asia and the third highest in the world.

A large number of wind mills installed in clusters are called wind farms, and feed power to the utility grid and produce a large amount of electricity

Wind energy is very useful as it does not cause any air pollution; after initial installation cost, the wind energy is very cheap

Advantages (i) It does not cause any air pollution. (ii) It is very cheap.

Disadvantage of wind generators are i) Noise Pollution ii) Blades may interfere with television

reception or with microwave communication

OCEAN ENERGYTIDEL ENERGY

The tides are daily movement of large bodies of water gravitational attractions between the sun, earth and moon.

Significance of tidal energy.

• Tidal power plants do not require large areas ~ valuable lands as they are on the bays or estuaries.  

• As the sea water is inexhaustible, it is completely independent of the uncertainty of precipitation (rainfall).

• It is pollution-free energy source, as it does not use any fuel and also does not produce any wastes.

OCEAN THERMAL ENERGY (OTE)

There is often large temperature difference between the surface level and deeper level of the tropical oceans.

This temperature difference can be utilized to generate electricity.

The energy available due to the difference in temperature of water is called ocean thermal energy.

The temperature difference should be of 200e or more is required between surface water and deeper water.

GEO-THERMAL ENERGY

Temperature of the earth increases at a rate of 20 -75°C per km, when we move down the earth surface. High temperature and high pressure steam fields exist below the earth's surface in many places. The energy harnessed from the high temperature present inside the earth is called geothermal energy.

1. Natural geysers

In some places, the hot water (or) steam comes out of the ground through cracks naturally in the form of natural geysers.

2. Artificial geysers

In some places, we can artificially drill a hole up to the hot region and by sending a pipe in it, we can make the hot water or steam to rush out through the pipe with very high pressure.

BIOMASS ENERGY

This is the energy from garbage.

The garbage of houses contains waste paper, plastics and several other waste materials.

It can be used to produce electricity.

Biomass energy can play important and vital role to meet energy crisis of the world. Biomass can be used as renewable source of energy.

Biomass is the organic matter, produced by plants or animals, used as sources of energy. Most of the biomass is burned directly for heating, cooling and industrial purposes

Ex: wood, crop residues, seeds, dung, sewage, etc,..

The bio-mass is directly used as a fuel but the efficiency of such furnaces is very low and it produces lot of smoke causing air pollution

• Solid biomass:

The use of trees, crop residues animal and human waste, house hold or industrial residues for direct combustion to provide heat.

• Biogas:

it is obtained an aerobically (without air) digesting the organic material to produce ethane. Animal waste and municipal waste are two common feed stocks for anaerobic digestion.

• Liquid bio-fuels:

They are obtained by subjecting organic materials to one of the various chemical or physical processes to produce a usable, combustible liquid fuel.

Bio fuels such as vegetable oils or ethanol are often processed from industrial or commercial residues such as biogas or from energy crops crown especially for these purposes.

Bio-gas It is mixture of methane, carbon dioxide, hydrogen and

hydrogen sulfide, the major constituent being methane Bio-gas is produced by anaerobic degradation of animal

wastes in presence of water Bio-gas is non-polluting, clean and low cost fuel No storage problems (direct supply from plant) The sludge left over is a rich fertilizer containing

bacterial biomass with most of the nutrients preserved as such

Bio-gas plants in our country are basically two types:1. Floating gas holder type2. Fixed dome type

Floating gas holder type bio-gas plant

NUCLEAR ENERGY• Nuclear energy is non- renewable source of energy, which is released during fission

(disintegration) or fusion (union) of selected radioactive materials.• Nuclear power appears to be the only hope for large scale energy requirements

when fossil fuels are exhausted.• The major advantage is that even small quantities of radioactive material can

produce enormous amounts of energy.Example:• Energy produced by a ton of U235 = 3 million tones of coal = 12 million barrels of oil.• Nuclear energy has been used in the generation of electricity in spaceships, marine

vessels, chemical and food-processing industry.Nuclear fission:

Nuclear fission reaction are based on the fission of U235 nuclei by thermal neutronsEnvironmental impact:

Nuclear fission power reactors generate large quantities of radio active fission waste products, which may remain dangerous for thousand of years. In addition these are no safe disposal methods.It is generated by fission (splitting the nucleus) and fusion (combining the small nucleus) of the atoms of certain elements such as Uranium-235

Nuclear fusionIt is a nuclear change in which lighter nucleus

are combined together at extremely high temperatures (l billion °c) to form heavier nucleus and a large amount of energy is released.

Two hydrogen-2 (Deuterium) atoms may fuse to form a helium at 1 billion °C with the release of large amount of energy.

Tarapur (Bombay),Narora (Uttar Pradesh),Kota (Rajasthan)Kalpakkam (Tamil Nadu).

FOSSILS FUELS

Fossils fuels (oil, coal, natural gas) are energy rich substances that have formed from the residues of dead organisms lived 200 to 500 million years ago. This matter was buried under layers of sediment & converted by heat and pressure into coal, oil and natural gas.

Fossil fuels largely consist of hydrocarbons, which are compounds of hydrogen and carbon. Some fossils fuel also contains smaller quantities of other compounds.

Most common and important fossil fuels are:

• Coal, lignite = solid fuel

• Petroleum = liquid fuel

• Natural gas = gas fuel

Majority of fossil fuels are being used in• Transportation• Industries heating• Generation of electricity.56% of world coal reserves are located in

Russia,28% of world coal is located in USA and Canada.5% of world coal are located India.

The major coal producing states in India are.• West Bengal,• Jharkhand,• Orissa,• Andhra Pradesh,• Madhya Pradesh• MaharastraMainly, there are three types of coal:• Anthracite or hard coal = 90% carbon content• Bituminous or soft coal = 85% carbon content• Lignite or brown coal = 70% carbon content