22 August 2010

Wind Turbines Blow

Most people wonder how much power a wind turbine can produce, and never stop to wonder how much power a wind turbine requires to operate. Mechanical engineer Jerry Graf believes that it is long past time for people to ask that question:
Big turbines often incorporate rechargeable batteries or ultracapacitors to power their own electrical systems. When those get depleted, the power must come from the grid. This power goes into running equipment such as yaw mechanisms that keep the blades turned into the wind; blade-pitch controls that meter the spinning rotor; aircraft lights and data-collection electronics; oil heaters, pumps, and coolers for the multi-ton gearbox; and hydraulic brakes for locking blades down in high winds.

Turbines in northern climes also need blade heaters to prevent icing. Reports I’ve seen say these heaters can consume up to 20% of a turbine’s rated power output. Many big turbines also need dehumidifiers and heaters in their nacelles. And until recently, large turbines employed doubly-fed induction generators that bleed power from the grid to create their magnetic fields. (It should be said, though, that designs now on the drawing boards use permanent magnets instead.)

Instances of low or no wind pose another problem. Large turbines may need to use their generators as motors to help get the blades turning. And some wind skeptics have posed a question about the direct-drive turbines now emerging from the labs: Large ships frequently must expend energy to slowly turn their heavy driveshafts when at port to prevent them from sagging. Could the same be said of these superlarge wind turbines?

Wind-farm operators don’t say much about turbine-power demands. Typically, turbine-power consumption is one of the factors that gets lumped into a wind-farm’s operation and maintenance costs. I’ve never found either a wind-farm operator or a wind-turbine maker willing to discuss these costs. It would not be much of an exaggeration to say the wind industry treats such information as a state secret. _MachineDesign
There are too many aspects to the operation of big wind farms which are treated as state secrets. No wonder the O-P reich promotes wind power so heavily. Politicians are no doubt attracted to the "all image and no substance" aspects of big wind power.

More bad news about big wind

...Jeffry Michel, an MIT engineering graduate living in Germany, once informed me that the average capacity factor in Germany is about 21%. In other words, if 1000 kilowatt hours of (electric) electricity from a windmill are theoretically available during a year, the average (or better the expected) amount accessed during the same time period would only be 210 kilowatt hours. A year or so ago one of the leading energy/environmental bureaucrats in Sweden calculated that with a capacity factor of 25%, four (4) windmills with a capacity of e.g. 1000 kilowatts could replace a nuclear installation of 1000 kilowatts with a capacity factor of 100%, and as a result, with existing (construction and variable) costs, the windmills were a better economic prospect. Bizarre calculations of this nature were probably responsible for making (and keeping) Sweden one of the poorest countries in Europe until the Second World War....
Adapted from an earlier Al Fin Energy posting


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Blogger Bruce Hall said...


I've seen these spires at DTX and they always seem to be moving... even at low wind speeds. Don't know whether they are feasible economically, but they make a political statement for the airport.


Sunday, 22 August, 2010  
Blogger Hell_Is_Like_Newark said...

Here in NJ, the govt. plans to build a bunch of them off shore. My electrical rates already went from about $0.12 to $0.18 per kWh to pay for the current solar and wind programs. Can't wait for the next increase. Cost me $500 to run my A/C during the summer heat wave. What will it cost me next year? $10,000?

Sunday, 22 August, 2010  
Blogger Barista Uno said...

A poor country like the Philippines is also toying with the idea of putting up these contraptions all over the place. Electricity rates in the country are the second highest in Asia, but isn't solar power a better way to go?

Wind or solar, coffee is good at

Sunday, 22 August, 2010  
Blogger KGould said...

Don't worry - there ARE people out there asking the questions. We just find it hard to get real answers in return!

What I ask people to do is imagine how many of these things will need to be put up to power larger cities. There is a wind turbine field in Ontario that is very close to the same land size of the town it services now.. Im sorry I cannot recall the name but watched it on a news channel a week ago. Anyhow, the same land size used up - Wow. Let's picture every city doing that... what will happen to our lovely open spaces and farm/ranch lands?

Monday, 23 August, 2010  
Blogger al fin said...

The wind is both intermittent and unpredictable. That's a huge problem for grid managers.

The sun is intermittent, but fairly predictable. The predictability helps but doesn't entirely make up for the intermittency on a daily basis and on a seasonal basis.

Monday, 23 August, 2010  
Blogger Mike Courtman said...

These things are very popular in New Zealand and make sense to some extent as we are a very windy country. Trouble is, there tends to an inverse connection between power demand and wind levels.

There is most wind in the spring and early summer, when power needs are moderate and least wind in the winter when power needs are greatest. With hydro power its the opposite, water levels are highest in the winter when power demand is greatest.

Unless an area has reasonably consistent levels of wind through the year, wind turbines aren't likely to be very cost-effective.

Argentina would probably have the greatest wind power potential, since it has plenty of wind most of the year as well as plenty of space to hid the ugly turbines.

Tuesday, 24 August, 2010  
Blogger gtg723y said...

The coast of Georgia is very similar, we have a lot of wind and a lot of sun. When we don't have sun we have wind, and when we don't have wind we have sun. That still does not take away from the fact that it takes more electricity to produce a windmill and keep it running than the windmill will ever be able to produce during its lifetime. Windmills are a net negative, and solar panels are not recyclable, expensive, and too inefficient. Hydro and Nuclear are the cheapest 0 CO2 producing sources of power we have, and Geothermal looks promising although I don't know enough about it to comment.

Wednesday, 25 August, 2010  

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“During times of universal deceit, telling the truth becomes a revolutionary act” _George Orwell

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