The joys of springs: how Kenya could steam beyond fossil fuel

Engineers are tapping the Rift Valley's subterranean energy to power an expanding economy

A faint smell of sulphur, a shrill hiss of gas and a Rift Valley panorama punctuated by 30 pillars of steam mark the frontline of renewable energy growth in Kenya.

This is the boundary between Hell's Gate national park and the geothermal plants that are increasingly powering one of east Africa's fastest-growing economies.