Wind Energy as a source of electricity - benefits overblown

Amazingly the limitations of using wind energy as a source of electricity generation in the UK and Europe are slowly becoming understood....

Costing the Earth BBC4

Wind Rush (First broadcast 30th August 2007 9.30 can be listened to again for 7 days only)

Wind power is a fast growing renewable energy sector in Britain. The government is investing massive amounts of money in its future. xperts interviewed on Costing the Earth claim the power Eof the wind to deliver electricity is being overestimated by companies keen to cash in on big subsidies.

In order to fight climate change we have meet targets set by the EU which wants 20% of our energy to come from renewable sources like the wind by 2020. The government has admitted its struggling, but says it is determined to meet its obligations. Companies which hit green energy targets are rewarded under the government’s Renewables Obligation Certificate Scheme or ROCs.

On paper wind power is a great proposition. We are the windiest nation in Europe – but despite the government having subsidised the wind industry to the tune of half a billion pounds so far - as yet its failed to deliver half of one per cent of our electricity needs.

Michael Jefferson Policies Chairman of the World Renewable Energy Network and former Chief Economist with Shell believes the industry is encouraged to exaggerate not only wind speeds but the amount of potential wind energy a farm can supply. He worries there are many badly sited poorly performing wind farms in England.

Engineering consultant Jim Oswald has analysed the figures submitted to the electricity watchdog Ofgem on every wind farm's load factor - the amount of wind generated across the year. The recommended load factor for a viable and efficient wind development is 30%, but he says the average across Britain is 28%. He says the problem lies with the volatility of the wind and although Britain is the windiest country in Europe, it’s not consistently windy enough to generate a regular energy supply.

Sometimes we have high winds and often no wind at all and there is no way of storing wind energy. He also says that many wind farms are being built in places where there will never be sufficient wind power to generate enough electricity. He has serious concerns that with no long term strategy for upgrading our electricity infrastructure over the next decade an over reliance on wind power could result in major power failures and increase our electricity bills by up to 50%.

See also Wuthering Heights Der Spiegel report August 20th 2007

The Dangers of Wind Power By Simone Kaiser and Michael Fröhlingsdorf
Wind turbines are appearing worldwide. They grow bigger and bigger, the number of dangerous accidents is climbing. How safe is wind energy?

Mishaps, Breakdowns and Accidents

After the industry's recent boom years, wind power providers and experts are now concerned. The facilities may not be as reliable and durable as producers claim. Indeed, with thousands of mishaps, breakdowns and accidents having been reported in recent years, the difficulties seem to be mounting. Gearboxes hiding inside the casings perched on top of the towering masts have short shelf lives, often crapping out before even five years is up. In some cases, fractures form along the rotors, or even in the foundation, after only limited operation. Short circuits or overheated propellers have been known to cause fires. All this despite manufacturers' promises that the turbines would last at least 20 years.

Insurance costs increasing in Germany

Among insurers, who raced into the new market in the 1990s, wind power is now considered a risky sector. Industry giant Allianz was faced with around a thousand damage claims in 2006 alone. Jan Pohl, who works for Allianz in Munich, has calculated that on average "an operator has to expect damage to his facility every four years, not including malfunctions and uninsured breakdowns."

Many insurance companies have learned their lessons and are now writing maintenance requirements -- requiring wind farmers to replace vulnerable components such as gearboxes every five years -- directly into their contracts. But a gearbox replacement can cost up to 10 percent of the original construction price tag, enough to cut deep into anticipated profits. Indeed, many investors may be in for a nasty surprise. "Between 3,000 and 4,000 older facilities are currently due for new insurance policies," says Holger Martsfeld, head of technical insurance at Germany's leading wind turbine insurer Gothaer. "We know that many of these facilities have flaws."

Flaws And Dangers

In December of last year, fragments of a broken rotor blade landed on a road shortly before rush hour traffic near the city of Trier.

Two wind turbines caught fire near Osnabrück and in the Havelland region in January. The firefighters could only watch: Their ladders were not tall enough to reach the burning casings.
The same month, a 70-meter (230-foot) tall wind turbine folded in half in Schleswig-Holstein -- right next to a highway.

The rotor blades of a wind turbine in Brandenburg ripped off at a height of 100 meters (328 feet). Fragments of the rotors stuck into a grain field near a road.

At the Allianz Technology Center (AZT) in Munich, the bits and pieces from wind turbine meltdowns are closely examined. "The force that comes to bear on the rotors is much greater than originally expected," says AZT evaluator Erwin Bauer. Wind speed is simply not consistent enough, he points out. "There are gusts and direction changes all the time," he says.

But instead of working to create more efficient technology, many manufacturers have simply elected to build even larger rotor blades, Bauer adds. "Large machines may have great capacity, but the strains they are subject to are even harder to control," he says.

Even the technically basic concrete foundations are suffering from those strains. Vibrations and load changes cause fractures, water seeps into the cracks, and the rebar begins to rust. Repairs are difficult. "You can't look inside concrete," says Marc Gutermann, a professor for experimental statics in Bremen. "It's no use just closing the cracks from above."

The engineering expert suspects construction errors are to blame. "The facilities keep getting bigger," he says, "but the diameter of the masts has to remain the same because otherwise they would be too big to transport on the roadways."

German wind turbine giant Enercon, for its part, considers the risks associated with offshore wind power generation too great, says Enercon spokesman Andreas Düser says. While the growth potential is tempting, the company does not want to lose its good standing on the high seas.

See for example

Dong Energy ( a Danish consortium formed this year from DONG, Elsam, ENERGI E2, Nesa, Copenhagen Energy’s power activities and Frederiksberg Forsyning) and the Swedish energy combine Vattenfall run the Danish Horns Rev and Nysted offshore wind farms and have completed an 8 year, 144 page year environmental impact study (PDF Alert / English),in conjunction with the Danish Energy Authority and Danish Forest and Nature Agency.The publication can be also ordered from the Danish Energy Authority’s Internet bookstore ISBN: 87-7844-625-2.

Offshore the availability of the small nearshore farms is also high, but in 2004 the availability for Horns Rev was low due to a comprehensive repair of the gears and transformers on all the Vestas turbines. However, in 2005 all turbines operated nearly 100% with an availability of 95%, where as the Siemens (Bonus) turbines at Nysted reached 97%.

Vestas has had increasing problems of reliability ..

Vestas, the world's largest producer of wind turbines, lost nearly DKK 1.2bn (EUR 116m) on sales of DKK 26.7bn (EUR 3.58bn)last year(2005) up 52% on the previous year. The company's board called the loss 'disappointing' and 'totally unacceptable'.

Three factors had helped cause the losses last year: disappointing North American earnings, a lack of components, and vastly increased guarantee provisions.

This was from the Vestas Annual report in 2005

“The most important technological challenge for the company is to increase product reliability”

“The group has given priority to project deliveries with relatively low margins to the US market…”

“…from the shortage of key components..”

“ Currently the main focus of the technology R & D is to reduce the number of component failures in Vestas’ products.”

"In accordance with the highly inentsified focus on product reliability, Vestas has decided to postpone ... production of the V120 - 4.5 Mw turbine to 2009..."

Then there are other problems which were highlighted

On this last point it is essential to read ...

See Interim Report - System Disturbance on 4 November 2006
union for the co-ordination of transmission of electricity

Section 5.1 Page 25

About 40% of the total generation units which tripped during the incident were wind power units. Moreover, 60 % of the wind stations connected to the grid at 22:09 tripped just after the frequency drop.

Sect 8.1 Page 51
"The events in the evening of 4 November 2006 have been the most severe disturbance in the more than 50-year history of UCTE regarding the number of involved TSOs and the amplitude of the registered frequency deviation."

Page 52
"During the disturbance, a significant amount of generation units tripped due to the frequency drop in the system which resulted in the increased imbalance. Most of this generation is connected to the distribution grid (especially wind and combined-heat-and-power)."

Finally the difficulties of controlling wind energy networks has all sorts of physical and financial consequences.....

Hugh Sharman is an Englishman living in Denmark and is a Principal in Inteco, a Danish energy brokering and consulting outfit.Here is a lucid and sensible document he has written, which anyone who wishes to consider the arguments about the use of wind powered electricity generation should read. (PDF Alert).Now this month he has published an item for Proceedings of the Institute of Civil Engineering, vol 158, p. 161 (not online but available at cost of US$33 – Abstract at end of this post). In this he provides a technical analysis of the problems of power distribution where generation is in the North and West but consumption in the South and East of the UK.