By Tim Probert

12 November 2008 - Renewable energy will overtake natural gas to become the second largest source of power generation worldwide "after 2010", according to the International Energy Agency.

Dr Fatih Birol, chief economist of the IEA, told Power Engineering International that electricity from renewable energy would be second only to that from coal in the overall global power generation mix before 2015.

He said: "This includes not only the so-called 'new renewables': wind, solar, biomass etc., but also large hydropower. Put together, renewables are going to take over natural gas to become the second largest source of power generation behind coal after 2010."

Dr Birol was speaking at the launch of the IEA's World Energy Outlook 2008, which states, "Renewables-based electricity generation is expected to grow substantially over the coming decades, benefiting from high fossil fuel prices, declining investment costs and government support.

"Before 2015, electricity from renewable energy sources is projected to overtake gas as the world's second largest source of electricity behind coal, rising from 18 per cent in 2006 to 20 per cent in 2015 and 23 per cent in 2030."

The IEA said in the period to 2015, most of the increase in renewable generation would come from hydropower and onshore wind farms. In the 30 OECD nations, the total projected increase in renewable electricity generation between 2006-2015 (including hydro) is expected to top the combined increase in fossil fuel-based sources and nuclear power.

Costs of power generation from renewables are expected to fall over time due to increased deployment, in particular solar PV and concentrating solar power. The costs of the more mature technologies, such as geothermal and onshore wind power, were projected to fall the least, while hydro investment costs were seen broadly flat to 2030.