In Electricity for Africa, Matt Ridley quotes a UN official who says, despite the troubles in Libya and the Sahel that make the news, the long-term problems are concentrated in Subsaharan Africa:

Just to get sub-Saharan electricity consumption up to the levels of South Africa or Bulgaria would mean adding about 1,000 gigawatts of capacity, the installation of which would cost at least £1 trillion.

Renewable generation will cost about 4-5 times what natural gas generation costs.

The economist Bjørn Lomborg has been making the case that getting energy and clean water to Africans is a higher moral priority than pursuing renewable energy. He still thinks climate change is a danger, but he thinks developing new energy technologies will get far better results than rolling out expensive and land-hungry renewables today.

Worth reading the whole thing.