I agree with the title of Jonathan Lloyd's March 31 letter, "Switch to renewable won't suffice," but agreement ends there.
More than 20 percent of electricity consumption in Denmark is now produced by windmills. That high a proportion most probably won't be possible in Japan due to the higher population density, but a considerable portion of Japanese electricity consumption could be delivered by wind turbines. Several huge offshore wind turbine parks have been constructed in Denmark and other countries. Japan has a very long coastline, the beauty of which has been destroyed by tetrapods and other ugly concrete structures designed for protection against tsunami.
Japan also has thousands of hot springs. It must be possible to utilize thermal power considerably more than is being done at present. Solar panels have a huge potential, but are not really seen anywhere in Japan.
Furthermore, possibilities for reducing electricity consumption are far from exhausted in Japan. Japanese houses contain hardly any thermal insulation. Thermal insulation not only reduces energy consumption for heating, but also reduces the need for air conditioning in summer. Air conditioners run on electricity and have a rather low efficiency compared to heaters. It takes much more energy to cool the air from 40 degrees C to 20 than to heat it from 0 to 20. Nothing has been done so far in Japan to insulate houses and offices.
Though it may not be possible to completely eliminate the need for nuclear power in Japan, the current number of 54 nuclear power plants can be significantly reduced, thereby reducing the risk of accidents like the one at Fukushima.