I was chatting to a mate over a couple of bottles of cava last week and he installs solar and wind gennies in Spain. He showed me the graph for output to wind speed and it is quite a steep drop off in power after the optimum is reached. We also played with the wind speed indicator, and though it was blowing hard, it wouldn't have made much juice! There is a new Rutland due out soon that should address this problem and we are holding out til then for a test.