When a huge offshore wind farm (consisting of a hundred turbines) was built near the North Kent coast, the operator, Vattenfall, said that its capacity was 300 megawatts. The project was launched with much publicity in September 2010, and we were told that it could power from 200,000 to 240,000 homes. It would also provide green jobs and would form an essential part of our 'energy mix'.
Let's have a closer look at some of these figures.
If the 300MW wind farm supplies 240,000 homes, this is equivalent to 1250 Watts per home.
The measured output has been an average of 75 megawatts, not 300.
This is 312 Watts per home; enough for three old-fashioned light bulbs.
I notice that this figure has not got into the papers, or onto the BBC.
The wind farm's average output, 80MW instead of the claimed 300MW, is one tenth of that of a typical gas-fired power station.
The turbines cost £780 million to build. They will receive subsidies of £60 million per year (for the next 20 years) and will receive £30-40 million for the electricity they produce.
For that amount of money, you could build a new gas fired power station which would give 1000 megawatts of power, continuously, 24 hours a day, supplying 240,000 homes with 4200W (4.2 kilowatts) each.
The wind power is therefore not only intermittent; it is 1000/80 times more expensive - about 12 times the price.
This does not include the multi-million pound alterations needed to the Grid infrastructure so that the wind power can be accepted onto the network. This extra cost should be debited to the wind energy producer (currently it is not) because it is a direct consequence of the wind energy programme.
The Government constantly talks about “green jobs” created through wind power but this is somewhat disingenuous.
We have no UK turbine manufacturers.
The picture below, for example, shows some wind turbine infrastructure being delivered to a location in Scotland last month:
At the huge London Array wind farm in the Thames, to be opened next year, 90% of the contracts in the £2billion project have been given to overseas firms.
The enthusiasm of the BBC for wind power is well known; a typical BBC report will assert that a small wind turbine provides the power for tens of thousands of homes.
Unfortunately few people know enough science to do the sums, and the assertion goes unchallenged.
They also forget to say "on the occasions when the wind is blowing at the correct speed".
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