On Tuesday 04 September 2007 17:15, Jed Rothwell wrote: > Horace Heffner wrote: > > >It probably isn't necessary to locate in North Dakota. > > Maybe not. North Dakota has the most wind at ground level, but I do > not know if there is as much variation at high altitude. > > Based on the map of high altitude wind linked to the SkyWindPower > site, I would say they should go to Canada. Today, anyway. Maybe it > varies from day to day. See: > > http://weather.unisys.com/upper_air/ua_vect_300.html > > > >Also the article implies an altitude of 15,000 ft is necessary: "But > >how do we > >get a working turbine up to the necessary height -- at least 15,000 > >ft (4600 meters) above the earth's surface? That's where helicopter > >technology comes in." It doesn't seem likely that altitude > >is necessary either. There is a diminishing return for higher altitudes. > > See their explanation: > > http://www.skywindpower.com/ww/page012.htm > > They quote a prof: "The strongest, steadiest and most persistent > winds occur in bands at the jetstream level some 10km above the > earth's surface. . . . The planetary boundary layer [where there are > problems] grows throughout the day as the thermal heating increases. > It varies in size from a few hundred metres at night to as high as 2 > km on the most convective days." > > > >The power from wind is proportional to the cube of the velocity, so > >the power increases with the 3/7 power of altitude. At 15,000 ft > >the power is only 60 percent more than at 5000 ft. > > 2 km = 6,600 feet. They want to go well above the planetary boundary > layer, up to at least say 3 km (10,000 feet). I suppose they have a > reason for aiming for 15,000 feet (4.6 km). > > It isn't just high wind power they want. It is consistent wind, with > few changes in direction, to avoid . . . luffing, I guess you would > call it, if this were a sailboat. > > Say, wouldn't it be a hoot if the biggest industry of the late 21th > century used a bunch of words from the age of sailing ships?!? "Come > about, into the wind. Bear away from those storm clouds!" > > - Jed > > How about a 'nuther suggestion. Put the wind farm aloft in the vicinity of the White House. More wind there than anywhere, especially in election years. But then the wind was blowin pretty hard in the Minnesota Twin Cities Airport restrooms recently as well.....
heh heh heh Standing Bear
