Load factor

The load factor of wind turbines put on a level playing field would be about 1%

Blaise Kelly (PE January) falls into the renewables trap of comparing wind load factor of 30% with coal at 39%.

They have two different meanings. The total winter peak demand reaches 60GW in the winter so we need power stations to cover at least 62GW. Often this is when the wind is not blowing and so it can't be counted. The nighttime load drops to two thirds of this. In the summer it can be as low as 20GW. At this stage the conventional power stations will have an average load factor of 33%. Nuclear gets a greater percentage especially when the fuel rods are old and it is difficult to throttle back hence the 59%. The small scale renewables like biomass and hydro have priority but are too small to have much effect. The problem with wind is the output has to be taken in priority over conventional power plants and reduces further their load factor. If the cost of electricity generated by wind was allowed to be compared to other forms and the cheapest used to supply the customer Wind would be backed out. The load factor of wind turbines put on a level playing field would be about 1% not 30%. Remember the coal/gas/nuclear generation average last year was 3.2p/kWh and the cheapest wind was 7.6p/kWh.

Mike Travers, Saline, Fife

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