Location, Location

April 9, 2010 · 0 comments

Opening a successful business is all about location, they say. And so it is with wind energy.

Though the United Kingdom, with 250 wind farms, has vigorously embraced wind generation of electricity, a new study paints a discouraging picture of the overall productivity because of siting problems.

The study, released by the energy regulator Ofgem, found that at least 20 wind farms in the U.K. are operating at less than 20% of their capacity, with some even dipping below 10%. This is well below a typical  farm, which generates around 30% of its maximum potential energy. According to the study, the least productive farm (Blyth Harbour in Northumberland) operates at just 7.9% of its maximum capacity; the Chelker reservoir in North Yorkshire isn’t much better, at only 8.7% of capacity.

Critics claim that government subsidies are leading developers to choose less-than-ideal locations (with at least 14 m.p.h. average wind), leading to the disappointing productivity.

“Too many developments are underperforming,” says Michael Jefferson, a professor at London Metropolitan Business School and environmental consultant. “The subsidies make it viable for developers to put turbines on sites they would not touch if the money was not available.”

British electricity consumers help subsidize the country’s renewable energy policy through the “Renewables Obligation” plan, which requires the country’s energy companies to establish renewable sources. The UK energy plan calls for 20% of all its electricity to come from renewable sources by 2020 (that figure was downgraded to 10-15% by the country’s energy minister); currently, the country gets about 4% of its energy from such sources.

Meanwhile a new article by Willett Kempton and colleagues in the Proceedings of the National Academy of Sciences affirms the message that location, determined by meteorological and climatological analysis, is the key to producing energy effectively from wind power. However, the authors radically rethink the typical meteorological considerations for wind farm locations:

Whereas today’s developers prospect for the windiest single site, we would advocate a broader analysis—to optimize grid power output by coordinated meteorological and load analysis of an entire region.

The authors (from the University of Delaware and SUNY-Stony Brook) used wind data from 11 meteorological stations, representing 2,500 km of the U.S. Eastern Seaboard, to show that a network of  turbines could be configured to overcome the typical intermittency that bedevils wind generated electricity.

The trick to making steady electrical power at high output is meteorological: use wide spacing of turbines to take advantage of the typical synoptic circulation of extratropical systems moving up the coast and then connect with high capacity transmission lines. The net result smooths out operations even during very low wind situations.  The authors suggest that further meteorological pattern analysis could refine the siting of turbines beyond the even spacing explored in the article

The implications for design also include rethinking the scale on which power generation is governed and coordinated, however, requiring a new Independent Service Operator to manage offshore generation and transmissions.

Alas, for the United Kingdom, the article is a bit more sanguine about the possibilities for such synoptic wind farm optimization:

[T]he lack of benefit seen by aggregating stations in the United Kingdom may be due in part to the roughly north–south orientation of the island, thus experiencing
their east–west passage of frontal systems nearly simultaneously.