Environmentalists hail renewable energy as a key to curbing climate change. Solar panels, wind turbines, geothermal power stations and hydroelectric facilities emit no carbon dioxide, unlike power plants that burn coal and oil. Renewables also make a lot of sense for an earthquake-prone country like Japan because, unlike nuclear plants, they pose virtually no risk of a large-scale disaster. Nevertheless, renewable alternatives account for a mere 4.1% of Japan's primary energy supply -- far below the figures for some other nations. Japan has conducive geography and world-class technology at its disposal. The question is, does it have the political will to make renewables more than supplementary sources of power?