Renewable energy
Renewable energy is derived from natural processes that are regularly replenished. Renewable energy sources and technologies include solar power, wind power, hydropower, geothermal energy, biomass, and biofuels. Each of these has unique characteristics which influence how and where they are used.[1]
About 18% of global final energy consumption comes from renewables, with 13% from traditional biomass (which is mainly used for heating) and 3% from hydroelectric power. The share of renewables in electricity generation is around 18%, with 15% of global electricity coming from hydroelectricity and 3.4% from new renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels).[2]
According to the International Energy Agency (IEA), renewable energy technologies can play an important role in addressing the challenges of moving towards clean, reliable, secure and competitive energy supply. Many countries have made progress in promoting renewables in their energy mix, but obstacles remain and, says the IEA, greater efforts are needed.[3]
Rationale for renewables
Renewable energy technologies are essential contributors to the energy supply portfolio, as they contribute to world energy security, reduce dependency on fossil fuels, and provide opportunities for mitigating greenhouse gases. The fuels that produce the most emissions of greenhouse gas are fossil fuels and they can be replaced by non-depletable sources of energy that produce much lower emissions of greenhouse gases:
...the transition from coal,oil, and gas to wind, solar, and geothermal energy is well under way. In the old economy, energy was produced by burning something — oil, coal, or natural gas — leading to the carbon emissions that have come to define our economy. The new energy economy harnesses the energy in wind, the energy coming from the sun, and heat from within the earth itself.[4]
The International Energy Agency estimates that nearly 50% of global electricity supplies will need to come from renewable energy sources in order to halve carbon dioxide emissions by 2050.
References
- ↑ International Energy Agency (IEA) (2003). Renewable energy... into the mainstream p. 9.
- ↑ Renewable Energy Network in the 21st Century (REN21) (2008). Renewables 2007 Global Status Report (Paris: REN21 Secretariat and Washington, DC: Worldwatch Institute).
- ↑ International Energy Agency (2008). Deploying Renewables p. 1.
- ↑ Lester R. Brown. Plan B 4.0: Mobilizing to Save Civilization, Earth Policy Institute, 2009, p. 135.