Small wind tubines. Usefull or not?

Sound like a good idea, doesn’t it? Wind is everywhere and free, so we all put a small wind turbine on our roof to make our own electricity. Another advantage is that wind turbines are low tech, so they must be cheap to produce and have a long lifespan.

Well, it turns out that that is not the case. After extensive testing in the Netherlands and the UK it turned out that the lifespan of small wind turbines is only about 5 years. They turn around at high frequencies, so there parts wear easily. And within these 5 years they are not capable to generate enough energy to pay themselves back. The problem is that the blades of these windmills are small which makes the torque they generate small. Also the available wind power in suburban areas is limits because of all the buildings.
There is probably a great future for wind energy, but small wind mills is not the answer. What we need is very large windmills placed in open areas. Offshore windmills at sea is a great idea. Bummer that they are so expensive and that it is not that easy to get the energy they produce inland to the consumers.