Africa is the least electrified place in the world. An estimated 550 million Africans have no access to electricity. Nearly half of African countries have a power crisis. Solving this huge problem is made more difficult by widespread poverty, and because most Africans live far from the grid, greatly adding to the cost of bringing electricity to them. Under these challenging conditions, there are no second chances for electrifying Africa: it must be done right the first time. Yet many of the continent's energy planners are pinning their hopes for African electrification on something as ephemeral as the rain, by pushing for a grid of large hydro dams across the continent.