In a series of articles in certain areas of the UK media (essentially the usual anti-wind Not in My Back Yard suspects) it has been “revealed” that wind turbines take, rather than contribute, power from the National Grid. Cue the usual semi-hysterical scribblings of the wind-watch hacks venting their spleens in mock indignation that wind farms are actually using energy rather than producing it. Critics and pro-fossil fuel lobbyists claim it is the pure folly that turbines should use power from the Grid.
While any wind farm operator would have been happy to explain the circumstances and reasons for temporary use of power to maintain turbines in certain weather conditions, the issue was seized upon and blown up by parts of the media after a person in North Wales noticed that the blades of a group of off-shore wind turbines out to sea were turning very slowly in non-wind and freezing conditions.
The plain facts are these: Wind turbines will only generate electricity when the wind is between certain limits, usually 10-50 mph. Where such wind parameters are not met and if the air temperature is below freezing, then failure to rotate the blades slowly would result in them icing up and failing to rotate and generate electricity when the winds picked up. This would require expensive maintenance work and could even damage the gears and rotors. Therefore wind turbines use electricity to keep their blades rotating slowly in very cold weather to prevent them icing up and to also power the systems within the nacelles of the turbines which turn the blades into the wind.
The fact is that almost all machines will use a small amount of electricity when “idling”. Think computers, laptops, TV screens and thousands of other items when in stand-by mode. All methods of producing power need to use electricity to function. Do you know how much power it takes to power up and down a nuclear reactor for example?
If one wanted to look for ways of saving energy from the National Grid then one could take a look at the (arguably) wasteful use of electricity to heat and light office buildings when no-one is there.
It makes good long-term economic sense to preserve the life of a wind turbine and reduce maintenance costs by using a small amount of Grid energy to prevent icing.
In fact, the actual story was exposed as itself being economical with the truth when someone contacted the North Wales wind turbine operator, RWE. They own 30 of the turbines in question and gave the facts: The turbines were not idling on the days in question but actually contributing an overall net power into the grid rather than taking it away.
Britain’s offshore and land wind turbines have a total capacity of 12.1 gigawatts, enough to power 8.8million homes. However, output was cut by unusually low wind speeds in the months of April May and June 2013, according to the UK Department of Energy and Climate Change. As I write, strong winds in the region of 20-50 mph are sweeping across the land and shores of the UK. Such are the vagaries of the weather- but it should be noted that UK wind farms produce electricity 70 to 85 percent of the time, depending on their location, contributing 10% of all the UK’s power needs.
