Renewable energy is natural energy which does

not have a limited supply and can be used again and

again and will never run out. Renewable resources can be replaced and

they are different from non-renewable resources like

fossil fuels that are gone.

According to the National Renewable Energy

Laboratory, using renewable resources

can save money while creating a

clean energy future. As fossil fuels

become less available, researchers are turning to

renewable energy sources to replace them.

Solar Energy Wind Energy

Hydro Energy Bio Energy

Solar Energy originates with the thermonuclear fusion

reactions occurring in the sun. It represents the entire Electromagnetic radiation.

Solar Energy can be used directly for

heating and lighting homes and other

buildings, for generating

electricity and for hot

water heating and solar

cooking.

The surface receives about 47% of the total solar energy that reaches the Earth. Only this amount is usable.

Solar panels consist of a series of solar cells that convert light from the

sun into DC electricity. It is used because it is more

cost effective than extending

power lines.

All chemical and radioactive polluting

byproducts of the thermonuclear reactions remain behind

on the sun, while only pure radiant energy reaches

the Earth.

Wind energy is the fastest growing renewable resource. They are influenced by the ground surface at altitudes up to 100 meters and is slowed by the surface roughness and obstacles.

A Windmill captures wind energy and then uses a generator to convert it to electrical energy.

Wind turbines are used to produce serious amounts of electricity. It is of two types :-

1. Large Turbine 2. Small Turbine

Able to deliver electricityat lower cost than smaller turbines, because foundation costs, planning costs, etc. are independent of size.

Local electrical grids may not be able to handle the large electrical output from a large turbine, so smaller turbines may be more suitable.

Wind Turbine generators convert wind energy into electrical energy.

The generator is attached at one end to the wind turbine and at the other end, it is connected to the electrical grid.

Wind energy is a domestic, renewable source of

energy that generates no pollution and has little

environmental impact.

The wind blows day and night, which allows wind-

mills to produce electricity throughout the day.

Flowing water creates energy that can be captured

and turned into electricity. This is called Hydroelectric power or Hydro Power. It is an

environmentally friendly way to generate electricity.

The most common type of hydro-

electric power plant uses a dam

on a river to store water in a reservoir. Water released from the reservoir flows

through a turbine, spinning it, which

in turn activates a generator

to produce electricity. But

some hydroelectric power plant

just use a small canal to channel

the river water through a

turbine.

A dam is built to trap water, usually in a valley where there

is an existing lake. Water is

allowed to flow through tunnels into

the dam, to turn turbines and

thus drive generators. Notice that

the dam is much thicker at the

bottom than at the top, because

the pressure of the water increases with depth.

Once the dam is built, the energy is virtually free.

No waste or pollution is produced.Electricity can be generated constantly. Much more reliable than wind, solar or

wave power.

Along with the rain and snow, sunlight causes plants to

grow. The organic matter that makes up those plant

is known as biomass. Biomass can be used to produce

electricity, transportation fuels or chemicals. The

use of biomass for any of these purposes is called

Bioenergy.

Biogas typically refers to a gas

produced by the biological breakdown of organic matter

in the absence of oxygen. Organic

waste such as animal dung, kitchen waste etc. can be converted

into a gaseous fuel called biogas.

Biogas originates from biogenic

material and is a type of Biofuel.

Biogas is produced by anaerobic

digestion or fermentation of Biodegradable materials such

as biomass, manure, sewage, green waste, plant material

and crops. Biogas comprises

primarily methane and carbon dioxide

and may have small amounts of

hydrogen sulphide and moisture.

It helps in saving Fossil fuels and also saves money

as well as cooking time. Improves hygienic conditions and rural

standard of living.Reduces air and water pollution.

It can be utilized for electricity production on sewage works.