THE SCALE OF SUN AND WIND

Ever since the TXU deal, Texas wind energy has been getting a lot of attention. More tomorrow.

Wind energy, surprisingly to some, has economies of scale, too
Matthew L. Wald, March 8, 2007 (International Herald Tribune)

- …When it comes to alternative ways of generating power, big may be better.
- Wind, solar and other renewable-energy technologies that were once considered more appropriate for single homes or small communities are reaching levels of scale and centralizing that were formerly the province of coal- and natural gas-fired plants and nuclear reactors. In other words, green is going giant…there are economies of scale to be gained.
…Arizona Public Service, an electric utility, is using an array of mirrors to concentrate sunlight and heat mineral oil; the heat vaporizes a liquid hydrocarbon, which runs a generator to make electricity.
- But this is no rooftop operation. There are six rows of mirrors, each nearly a quarter-mile, or four-tenths of a kilometer, long…The project produces one megawatt of power — enough to run a hospital or a large shopping center — but the company that installed it, Acciona Solar Power (formerly Solargenix), expects to…[produce] 64 megawatts with similar technology…a half-dozen utilities [are]…considering a joint project to build a 250-megawatt plant based on the same technology…
- But it is not just corporations that are finding that bigger may be better...
- Hull, Massachusetts…in the early 1980s [built] a wind turbine…Five years ago, Hull…built a wind machine 16 times larger…Last year the town installed Hull 2, which at 1.8 megawatts is three times larger. Now Hull is considering four new turbines that can produce 3.6 megawatts each…Hull's economics are being repeated around New England and the world…

- At Siemens Power Generation, which builds equipment for wind turbines and other generators, Randy Zwirn, chief executive, said that the only limit to wind-turbine size might be how long a blade could be transported to the site. The company's 3.6-megawatt machine uses a blade that is about 175 feet long.
- Other companies want to build even bigger wind turbines with capacities as high as seven megawatts…But in Nantucket Sound, 3.6-megawatt turbines are considered big enough. On a windy day, the 130 machines would produce as much power as a modest-size plant burning coal or natural gas…
- While mirrors in the desert cannot operate at the rooftop scale, the kind that can, photovoltaic cells, which turn sunlight into energy, may also work better on a big scale…