Green subsidies

How long will taxpayers have to pay out billions to subsidise wind or solar power? Lesley Curwen's guests are Dimitri Zenghelis, from the Grantham Institute of the London School of Economics who also advises Cisco, Professor Claudia Kemfert, Head of the Department of Energy, Transportation and Environment at the German Institute of Economic Research, David Buchan, senior research fellow at the Oxford Energy Institute, and comedian Colm O'Regan.

Plus, we discuss the unlikeliest sought-after commodities - insect excrement and the guar bean.