This paper outlines the growing need for energy in the developed and developing countries and the acute population growth, which will exceed 10 billion by the year 2050. It describes the achievement and progress made in hydropower, biomass conversion, geothermal, solar thermal technology, wind energy conversion, and the increasing usage of photovoltaics. The paper also addresses the barriers and problems facing renewable energy users and producers. It is evident that global warming is setting in and is going to change the climate as well as the terrain of many countries unless drastic measures are taken. The recent Kyoto meeting emphasized the importance of limiting CO2 emissions and abiding by some form of agreement to reduce emissions. The present study concludes that renewable energy penetration into the energy market is much faster than was expected in recent years and by 2030, 15-20% of our prime energy will be met by renewable energy.