There are more sensible renewable power sources we can use, but they cannot be the whole answer. If they are not reliable, then we should not rely on them.

In the UK, Hydroeltricy has some potential, both as some major dams, and micro-power installations, as other countries do. In various areas, such as the S.W USA, where the sun does shine, almost all the time, and there is the space, solar power makes sense.

The standard answer should be Nuclear though. It's not good, but it's less bad than more Fossil fuels.