Renewable Energy is energy derived from
resources that are regenerative or for all practical purposes
cannot be depleted. For this reason, renewable energy
sources are fundamentally different from fossil fuels,
and do not produce as many greenhouse gases and other
pollutants as fossil fuel combustion. Mankind's traditional
uses of wind, water, and solar energy are widespread in
developed and developing countries; but the mass production
of electricity using renewable energy sources has become
more commonplace recently, reflecting the major threats
of climate change, exhaustion of fossil fuels, and the
environmental, social and political risks of fossil fuels.
Consequently, many countries promote renewable energies
through tax incentives and subsidies.
Renewable energy accounts for about 14%
of the world's energy consumption, but the technical potential
is large enough to cover many times current and several
times projected energy consumption in 2100 (see below).
Renewable technologies such as geothermal and hydropower
are often economically competitive without subsidies.
Other technologies such as solar power are substantially
more expensive, although future costs may decline to a
fraction of current levels.
