Ocean Powerhouse was a BBC show about offshore windfarms broadcast a couple of days ago. It can be seen here if you can get the iPlayer. It's a strange show, focusing mainly on the assembly process for a wind turbine, with lots of "corblimeying" over the size of everything and the technical challenges involved. The music makes it feel like a corporate puff-piece and there were indeed several opportunities for the various companies involved to sell their wares. However, a measure of balance was achieved: in the shape of a short interview with Dieter Helm, who said that the whole idea of offshore wind is a bit stupid, particularly in the current economic climate, and by the summing up, in which narrator David Shukman left it as an open question as to whether there is actually a future for offshore wind.
In these terms then, this was a rather unusual programme for the BBC in that for the most part it avoided most of the usual green propaganda.
That said, Shukman did blot his copybook and in a very serious way. He reported that it would take 200 turbines to replace a conventional power station. He should probably have realised that his maths was going to be checked, and unfortunately for him it was. Via the Countryside Guardian email newsletter comes this from Emeritus Professor Peter Cobbold:
The turbines were 5MW Installed Capacity. So allowing for a load factor of 33%, their real output is one third of 5MW. That means it needs 600 windmills to replace a 1GW conventional power plant.
Again the need for back-up plant to cover the holes in wind power output is completely ignored.
I don't know about you, but I think if Shukman had reported that it was going to take 600 turbines to replace a conventional power station viewers would have gained a remarkable insight into the sheer insanity of offshore wind. The conflating of installed capacity of windfarms with their actual output is an problem that has been repeated so often over the years that it is hard to accept it as an error any longer.