Erm but of course to provide erm electricity on a larger scale, you can't put these things too close together, you need about  er a thousand of those to, for example, to replace say a power station like Didcot  and er and a thousand of these windmills would o occupy about three hundred square miles, and this is what three hundred square miles looks like  er it's, it's the major part of, of central  L you wouldn't put them in central London of course but erm  gives you some idea of the sort of area you'd have to devote to wind farms if you were to use this particular type of er of energy.