In recent years Renewable Energy has become a high profile issue and the interest is growing all the time.
Most energy sources can be consumed in two ways, directly and indirectly when converted to another form of energy. For example, wood can be burned directly as a primary energy source to heat space, or it can be burned to produce heat to generate electricity, a secondary energy source. Likewise, geothermal energy can be used directly as heat for industrial process or bathing, and indirectly to generate electricity. The data below highlights both uses but focuses mostly on indirect use for generating electricity and to a lesser extent liquid or gas fuels. Some energy sources, such as hydro or wind power are mostly used to generate electricity but they can be used directly, as both sources have been used to raise water for irrigation. It is important to bear these distinctions in mind because the profiles of primary and secondary use of renewable energy are quite different.
Most consumption of primary renewable energy is of traditional fuels in developing countries, such as wood or animal dung. However, the generation of electricity, a secondary energy source, presents quite a different picture. Renewables account for 18.5% of total electricity generation. Hydro power accounts for 86% of renewables’ share of electricity production and biomass for only 6%.
As a primary energy source biomass and waste is a significant resource, accounting for 9.8% of TPES. Also known as CRW (combustible renewables and waste), because of its wide non-commercial use in developing countries it is much the largest source of renewable energy, representing 76.7% of the total supply of renewable energy.
The IEA forecasts that renewable energy supply will grow at 1.3% a year for the next thirty years, slower than the rate of growth of conventional energy and that the share of renewable energy in TPES will decline from 13.4% in 2005 to 12.5% in 2030.
In the last 20 years consumption of hydro power has increased the fastest, at an annual rate of 15.4%, followed by natural gas at 2.6% and coal at 2.2%. Nuclear has increased at 1.9% and biomass at 1.8%. Oil has had the slowest rate of increase at 1.3%.