04-06-04

On a stretch of reclaimed land in northern Germany looms the tallest wind generator in the world, its curved blades tensed for battle with the air.

The Wybelsum polder on which the windmill E-112 is sited is emblematic of how the limits of modern technology are being tested by one of mankind's most ancient sources of energy The flat, wind-battered land hosts one of Europe's biggest wind farms, nearly six km (four miles) long, run jointly by four companies eager for a stake in the new gold rush.

As oil prices spike to new highs, driven by Mideast security fears and rising consumption by emerging countries, windpower and other "renewables" have become buzzwords. But developing and exploiting alternative energy -- the theme of a four-day worldwide conference opening in Bonn -- is tougher than its wholesome image suggests.

At first sight, mighty E-112 is almost lost in the forest of other turbines, until one spots the red paint on its tower and the two lights that flash at the top to warn off low-flying aircraft. You really only get an idea of its immense size from close up. Nearly 180 metres (590 feet) tall -- more than half the height of the Eiffel Tower -- it has a lift installed inside to save the leg muscles of its maintenance engineers.

E-112 was preceded by two prototypes, but is the only one to be exploited commercially by the regional electricity supplier EWE in a sort of real-time testing phase.

EWE and its constructor Enercon consider it "an investment for the future" but refuse to quantify how much.

The turbine's maximum annual output of 4.5 MW is enough to meet the electricity needs of 4,250 three-person houses, Enercon's spokeswoman Nicole Weinhold said. That is still just a tiny fraction of production from a nuclear reactor, typically 1,000 to 2,000 MW, at a commercial power station.

So it's hardly surprising that German wind farms, whose production of 14,960 MW in late March was a third of the global capacity, supplies only 6.2 % of the electricity used, according to Germany's national wind energy association BWE. But with Germany phasing out atomic power, traditional energy sources such as coal running out and with the country obligated under the Kyoto Protocol to cut its greenhouse gases, renewable sources such as wind are, literally, heaven-sent.

Emden, the district where this windfarm is situated, is exemplary. It has turned a wartime bunker into a solar centre while one of its museums is heated by geothermal energy. Klaus von Ahrens, of the renewable energy management company IfE, which operates the windfarm, says the polder's 54 "small" wind turbines already crank out enough electricity to meet the needs of residents as well as a Volkswagen factory employing 10,000 people.

According to the BWE association, wind energy will be supplying 30 % of Germany's electricity by 2030. The government is also optimistic, putting the figure at a slightly lower but still formidable 25 %. But daunting problems remain, if either target is to be met.
"It's a question ofspace," sighs Weinhold. "There are already over 15,000 windmills in Germany. Many are small, with only a tenth of the capacity of the latest designs, and they are also noisier. They need replacing."

If there isn't enough space on land, the alternative lies offshore. There, construction costs are understandably enormous. The industry is taking notice. Repower, an Enercon rival, has started work on a five-MW turbine, and its spokeswoman Bettina Linden predicted the first such windmills would be built at sea in 2006.

Wilfried Hube, an engineer for EWE on wind and solar energy, is doubtful of such claims.
"You need perfect precision machinery, and you don't know how long that is going to take."

Source: PetroEnergy Information Network