Global investment in renewable energy hit a record high of £165 billion last year with solar power attracting more than half the total spending, according to new UN figureds.
Investment in solar energy surged to £94bn in 2011, a year-on-year increase of 52 per cent thanks to strong demand for rooftop photovoltaic installations in Germany, Italy, China and Britain.
China was responsible for almost a fifth of the total investment volume, spending £33bn on renewable energy last year.
The United States was close behind with investments of £32bn as developers sought to benefit from government incentive programmes before they expired. Germany, Italy and India rounded off the top five.
The UN report noted that developing countries were also exploring the use of renewable energy other than hydropower, which has long been a popular source in poor countries.
Countries in east Africa are seeking to take advantage of the abundant geothermal capacity in the Rift Valley region.
Kenya aims to meet half of its electricity needs with geothermal power by 2018, while Djibouti, Eritrea, Rwanda, Tanzania and Uganda are also exploring geothermal use.
However more than 80 per cent of electricity consumed worldwide still comes from fossil fuels.
