Solar power surpassed wind to become the world's fastest growing energy source last year, says a report released by the Worldwatch Institute last month. In 1997 shipments of solar cells were some 126 MW, up 43% from a year earlier. Wind grew by just over 25% or 1566 MW, albeit on a larger base. Wind power, however, remains the fastest growing energy source this decade, says Molly O'Meara, co-author with Chris Flavin of the report "Solar Power Markets Boom," to be published next month in the Worldwatch magazine. Total installed wind capacity was just 10 MW in 1980, 200 MW in 1990, whereas last year it had reached 7,630 MW. O'Meara attributes last year's astonishing rise in PV sales to a new program established by the Japanese government. In 1997 in Japan, 9,400 solar cells were installed on home rooftops, while another 13,800 are expected to installed by the end of 1998. The near term growth rate of solar will depend upon how much that trend is duplicated in the United States and Europe. But both sources of clean energy, wind and solar, are overall expected to continue growing rapidly, especially because of global warming, says O'Meara. Worldwatch, based in Washington DC, tracks emerging global problems and trends.