B&Q sent me an email the other day advertising their new Windsave rooftop turbine.
This is likely to considerably boost penetration of this kind of product. I am a big supporter of wind power, and I think it would be great if everybody had a 1 kW wind turbine on their house, providing most of their electricity needs and recharging their cars.
However, the question remains of whether rooftop locations are suitable for this kind of product. The Centre for Alternative Technology express concerns about turbulence and stresses on the building structure.
If a turbine needs a clean airflow and doesn't get it, it will not generate much power and will wear out quickly, perhaps having a zero or negative life cycle impact on carbon emissions, and obviously failing to deliver an acceptable return on investment.
If it damages the structure of the building, this would have to be repaired at great expense and not insignificant environmental cost.
CAT's advice is quite old - it has been there for a while. Perhaps the latest breed of turbines has overcome these problems. But perhaps it hasn't. These issues don't seem to be addressed in the marketing of new turbines. So this could be a big mis-selling scandal, exacerbated by well meaning promotion by supporters of renewable energy.
Newsnight's ethical man Justin Rowlatt is getting one. I will see how he gets on before considering one for myself.