Four different sources confirmed last month that the installed wind power generating base worldwide has surpassed 10,000 MW. First came the April issue of Windpower Monthly's "The Windicator," followed three weeks later by the release of BTM Consult's "World Market Update 1998," followed one day later by a joint announcement by the American and European wind energy associations and, at around the same time, a statement by the International Energy Agency (IEA). The significance of the 10,000 MW milepost is not so much in its passing, but in the speed at which it was reached. Even the most optimistic industry goals are being scored ahead of time. The rate of growth of wind power installation last year was 66% greater than in 1997, while the cumulative megawatt capacity increased by 31%, according to BTM Consult. A Danish firm, BTM predicts that the market five years ahead will have an annual growth of 16.6%, and cumulative capacity will be growing 25.6% yearly. The largest market in 1998 was Germany which added 793 MW, followed by the US with 577 MW, Spain with 368 MW and Denmark with 310 MW, reports BTM. It predicts that between now and 2003, a further 21,000 MW of wind power will be added to the global generating base, yet another upwards revision of BTM's annual market projections, nearly all of which have been too conservative to date. In their joint announcement, EWEA and AWEA say world wind capacity has doubled every three years, that the rate of expansion has been 25.7% this decade, and that the cost of electricity from wind plant has fallen to one-sixth of what it was in the early 1980s. "Industry analysts see the cost dropping by an additional 20% to 40% by 2005," they say. The IEA says wind energy equipment sales topped $2 billion last year and that 80% of world capacity is in five countries: Germany, US, Denmark, India and Spain.