Wind turbines consume a lot of power - sometimes, it is a lot more than they generate. Case in point from Breitbart:
As Britain Freezes, Wind Farms Take Power From Grid to Prevent Icing
As Britain shivers under a blanket of snow and ice, it has emerged that offshore windfarms have been idling to prevent icing up – and drawing electricity off the national grid to do so. Critics have pointed out the “folly” of having windfarms idle in a cold snap, but industry experts insist that all forms of power generation involve some electrical input.
The issue has been raised by Brian Christley, a resident of Abergele, Wales, who wrote to the Daily Telegraph to say: “Over the weekend just gone, the coldest of the year so far, all 100-plus off-shore wind turbines along the North Wales coast were idling very slowly, all using grid power for de-icing and to power their hydraulic systems that keep the blades facing in the same direction.
“Thanks to Ed Davey, the Energy and Climate Change Secretary, we will be subsidising these follies for the next 30 years. And then, if we continue to vote for technically naive green politicians, for further periods after that.”
I had written about energy consumption by wind turbines before here: Windpower's dirty little secret - an excerpt:
Among the wind turbine functions that use electricity are the following:
- yaw mechanism (to keep the blade assembly perpendicular to the wind; also to untwist the electrical cables in the tower when necessary) -- the nacelle (turbine housing) and blades together weigh 92 tons on a GE 1.5-MW turbine
- blade-pitch control (to keep the rotors spinning at a regular rate)
- lights, controllers, communication, sensors, metering, data collection, etc.
- heating the blades -- this may require 10%-20% of the turbine's nominal (rated) power
- heating and dehumidifying the nacelle -- according to Danish manufacturer Vestas, "power consumption for heating and dehumidification of the nacelle must be expected during periods with increased humidity, low temperatures and low wind speeds"
- oil heater, pump, cooler, and filtering system in gearbox
- hydraulic brake (to lock the blades in very high wind)
- thyristors (to graduate the connection and disconnection between generator and grid) -- 1%-2% of the energy passing through is lost
- magnetizing the stator -- the induction generators used in most large grid-connected turbines require a "large" amount of continuous electricity from the grid to actively power the magnetic coils around the asynchronous "cage rotor" that encloses the generator shaft; at the rated wind speeds, it helps keep the rotor speed constant, and as the wind starts blowing it helps start the rotor turning (see next item); in the rated wind speeds, the stator may use power equal to 10% of the turbine's rated capacity, in slower winds possibly much more
- using the generator as a motor (to help the blades start to turn when the wind speed is low or, as many suspect, to maintain the illusion that the facility is producing electricity when it is not, particularly during important site tours) -- it seems possible that the grid-magnetized stator must work to help keep the 40-ton blade assembly spinning, along with the gears that increase the blade rpm some 50 times for the generator, not just at cut-in (or for show in even less wind) but at least some of the way up towards the full rated wind speed; it may also be spinning the blades and rotor shaft to prevent warping when there is no wind
Could it be that at times each turbine consumes more than 50% of its rated capacity in its own operation?! If so, the plant as a whole -- which may produce only 25% of its rated capacity annually -- would be using (for free!) twice as much electricity as it produces and sells. An unlikely situation perhaps, but the industry doesn't publicize any data that proves otherwise; incoming power is apparently not normally recorded.
More at the excellent AWEO.ORG website - lots of links to data there.
Something the wind people also fail to mention is that for every megawatt of wind capacity, there is also a gas turbine of the same capacity running on hot standby for when the wind fails. Wind power is not baseload capacity.
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