A review and future prospects of renewable energy in the global energy system

Global energy consumption in the last half century has rapidly increased and is expected to continue to grow over the next 50 years,however,with significant differences.The past increase was stimulated by relatively "cheap" fossil fuels and increased rates of industrialization in North America,Europe and Japan;yet while energy consumption in these countries continues to increase,additional factors make the picture for the next 50 years more complex.These additional complicating factors include China and India's rapid increase in energy use as they represent about a third of the world's population;the expected depletion of oil resources in the near future;and,the effect of human activities on global climate change.On the positive side,the renewable energy(RE) technologies of wind,bio-fuels,solar thermal and photovoltaics(PV) are finally showing maturity and the ultimate promise of cost competitiveness.