Countries across the world, from Guatemala to Papua New Guinea, are beginning to plug into geothermal energy as a new and promising alternative to coal and oil-fired power generation.

The century-old energy technology that taps steam from hot underground rocks is also poised for a massive expansion up East Africa's Rift Valley in the 21st century. The United Nations Environment Programme (UNEP) and the Global Environment Facility (GEF) have completed a project testing advanced seismic and drilling techniques in Kenya that has exceeded all expectations.

Wells of steam, able to generate 4-5 MW of electricity and one yielding a bumper amount of 8MW – enough to power about 5,700 homes – have been hit using the new technology. This could mean a saving of as much as $75 million for the developer of a 70MW installation as well as reduced electricity costs for generators and consumers, experts estimate.

Achim Steiner, UN Under-Secretary General and UNEP Executive Director, said: "Combating climate change while simultaneously getting energy to the two billion people without access to it are among the central challenges of this generation. Geothermal is 100 per cent indigenous, environmentally-friendly and a technology that has been under-utilized for too long."

"There are least 4,000MW of electricity ready for harvesting along the Rift. It is time to take this technology off the back burner in order to power livelihoods, fuel development and reduce dependence on polluting and unpredictable fossil fuels. From the place where human-kind took its first faltering steps is emerging one of the answers to its continued survival on this planet," he added.