Last month, I blogged about the Special Report on Renewable Energy Sources and Climate Change Mitigation of the Intergovernmental Panel on Climate Change (IPCC), for which I was a coordinating lead author. In that report we found that by 2050, roughly 80 percent of global energy demand could be met by tapping renewable sources. The IPCC’s best-case prediction is contingent on a big caveat, however. It is that government policies must “play a crucial role in accelerating the deployment of Renewable Energy (RE) technologies.”

Fair enough, but which policies work best? Which can be replicated widely? Which sectors need more radical new approaches? Given the complexity of energy technologies, and markets, modes of power generation, transmission, distribution, consumption, metering and billing, and