The crisis at the Fukushima No. 1 nuclear power plant has prompted the government to launch a seemingly radical rethink of Japan's energy policy. On May 25, Prime Minister Naoto Kan announced that Japan will generate 20 percent of its electricity from renewable sources by the early 2020s, but without clearly saying that Japan will reduce its dependence on nuclear power and fossil fuels.

Currently, Japan imports nearly 80 percent of its energy supplies, and nuclear power accounts for 30 percent of the nation's electricity generation. Renewable energy resources such as wind and solar account for only about 1 percent. When hydropower is added in, the total is about 9 percent.

The challenge of achieving the new target will be daunting, but a report released last month by the Intergovernmental Panel on Climate Change (IPCC) suggests that it is achievable. By mid-century, close to 80 percent of the world's energy supply could be met by renewables if the right public policies are put into place, the report states.