See: http://www.renewableenergyworld.com/rea/news/article/2012/04/wind-turbine-blades-keep-growing
It does not say how long they are, but only that they are 20% longer than they were a few years ago. Anyway, the longer the blade, the larger the cross-section it sweeps, and the more power you get. QUOTE: "The industry as a whole continues to focus its onshore efforts in the 1.6 MW-3.5 MW segment, while the offshore segment has moved away from 5 MW systems and is graduating to 6 MW-7 MW offerings to cope with larger offshore farms at greater water depths and greater distances from shore. The interplay between onshore and offshore wind turbine portfolios has left a noticeable gap in the 3.5 MW-5 MW segment." The ratio of actual to nameplate is much better offshore than onshore. Typically, they find places where it is about 40%. Offshore wind is immensely powerful and surprisingly predictable. It powered all of world oceanic trade until 1850, moving millions of tons across oceans and seas. 6 MW nameplate is approximately 2.4 MW actual, so it would take roughly 420 of these to replace one Japanese nuke plant. At present there are 53 nukes sitting there, turned off. One is running. Given the now robust local opposition to nuclear power I doubt that most will ever be turned on again. There is no chance additional ones will be built. Nuclear power in Japan is dead, dead, dead & gone. It turns out Japan has a great deal more offshore wind than people though a few years ago. In other words, you could replace those nuke plants with 22,000 wind turbines. That's not an impossible number. It would be cheaper than the cleanup cost for the Fukushima accident. Of course there are many difficult technical problems such as how to store energy, but installing 20 thousand turbines in Japan would take 30 years and over that time I think the problems could be solved. In real life you would want to use a lot of solar power, because people in Japan need electricity the most when the sun is shining brightly, for air-conditioning. Especially in southern Japan. Worldwide, wind power increases by around 20 GW nameplate. That's the increase, above replacements. That is the equivalent of building ~6 nukes, which is probably more than nuclear power increased in its heyday back in the 1970s. Certainly the sustained growth in wind power is greater than nukes were. - Jed
