How Much Wind?
Wind power deserves most of the accolades it has garnered as the most attractive green power source. This technology has improved dramatically in the last two decades, to the point that in some locations it is nearly competitive with power from incremental fossil-fuel power plants, even without the subsidies it usually enjoys. But as this article from The Economist describes (subscription may be required), there are other limitations to its spread beyond the NIMBY-ish opposition I've highlighted previously. (See my posting of 5/6/04, for example.)

There are two further potential challenges, depending on how the local power market is set up. The first relates to the difference between the rated capacity of the installed wind turbines and the actual average output, based on local wind conditions that differ from what was expected. The second is a function of the ability of the local power grid to manage the natural variability in the output of wind farms without having to pay for conventional backup capacity that runs up the cost to customers and reduces the effective benefit of wind. The fact that grids are typically public utilities and most new power projects are operated by unrelated companies amplifies this problem.

It should disturb both wind power advocates and potential developers that E.ON, the big German utility, is quoted in the article as experiencing a six-to-one shrinkage of theoretical versus actual wind power due to the combination of the factors above. This suggests that much better planning and coordination are required before new wind farms are built, so that they are put in the locations with the best combination of wind conditions and flexible grid accommodations. Otherwise, the experience of wind farm and grid operators is likely to deter many new installations, forcing utilities back towards more traditional generation sources, such as coal.