|
Renewable Energy
In the past century,it has been seen that the consumption of non-renewable
sources of energy has caused more environmental damage than any other human
activity. Electricity generated from fossil fuels such as coal and crude oil has
led to high concentrations of harmful gases in the atmosphere.This has in turn
led to many problems being faced today such as ozone depletion and global
warming. Vehicular pollution has also been a major problem.
Therefore,alternative sources of energy have become very important and
relevant to today's world.These sources,such as the sun and wind,can never be
exhausted and therefore arc called renewable.They cause less emission and are
available locally.Their use can. to a large extent,reduce chemical,radioactive,
and thermalpollution. They stand out as a viable source of clean and limitless
energy.These are also known as non-conventional sources of energy.Most of the
renewable sources of energy are fairfy non-polluting and considered clean though
biomass,a renewable source,is a major polluter indoors.
Solar Energy
Solar energy is the most readily available source of energy.It does not
belong to anybody and is,therefore,free.It is also the most important of the
non-conventional sources of energy because it is non-polluting
and,therefore.helps in lessening the greenhouse effect.
Solar energy has been used since prehistoric times.but in a most primitive
manner.Before 1970,some research and development was carried out in a few
countries to exploit solar energy more efficiently,but most of this work
remained mainly academic.After the dramatic rise in oil prices in the
1970s,several countries began to formulate extensive research and development
programmes to exploit solar energy.
When we hang out our clothes to dry in the sun,we use the energy of the
sun.In the same way, solar panels absorb the energy of the sun to provide heat
for cooking and for heating water.Such systems are available in the market and
are being used in homes and factories.
Solar energy can also be ursed to meet our electricity requirements.Through
Solar Photovoltaic(SPV)cells,solar radiation gets converted into DC electricity
directly.This electricity can either be used as it is orcan be stored in the
battery.This stored electrical energy then can be used ac night.
Hydro Power
Hydro power is one of the best,cheapest,and cleanest source of
energy,although,with big dams,there are many environmental and social
problems.Small dams are,however,free from these problems.This is in fact one
ofthe earliest known renewable energy sources.in the country(since the beginning
of the 20th century).
In fact,for the last few hundred years,people living in the hills of the
Himalayas have been using water mills.or chakki,to grind wheat.Besides being
free from the problem of pollution.small hydropower plants arealso free from
issues and controversies that are associated with the bigger projects.namely
affecting the lives of thousands of people living along the banks of the
rivers.destruction of large areas under forest.and seismological threats.
New environmental laws affected by the danger of global warming have made
energy from small hydropower plants more relevant.These small hydropower piants
can serve the energy needs of remote rural areas independently.The real
challenge in a remote area lies in successful marketing of the energy and
recovering the dues.Local industries should be encouraged to use this
electricity for sustainable development.
It is a technology with enormous potential.which could exploit the water
resources to supply energy to remote rural areas with little access to
conventional energy sources.It also eliminates most of the negative
environmental effects associated with large hydro projects.
Energy From the Sea-Ocean Thermal,Tidal and Wave Energy
On an averaige,the 60 million square kilometre of the tropical seas absorb
solar radiation equivalent to the heat content of 245 billion barrels of
oil.Scientists feel that if this energy can be tapped a large source of energy
will be available to the tropical countries and to other countries as well.The
process of harnessing this energy is called OTEC(ocean thermal energy
conversion).It uses the temperature differences between the surface of the ocean
and the depths of about lOOOm to operate a heat engine.which produces electric
power.
上一页 1 2 3 4 5 下一页
|
|