As I mentioned when expressing doubt about Bloom Boxes, many environmentalists assume that distributed generation of electricity is inherently preferable to large-scale generation and transmission. As I have argued in the past, there are good reasons to argue the converse. Micro wind turbines are especially dubious, given that the energy output from turbines increases with the diameter of the blades. Those little rooftop turbines some people install just don’t make sense, unless they live in very remote and windy areas. In a place as northern and cloudy as Britain, home solar photovoltaic arrays may make even less sense, especially if investments in more cost-effective options like improving efficiency of energy use have not yet been made. Saving many kilowatt-hours a day through better insulation beats producing a trickle of electricity, especially given that it is less costly.
In a recent essay, George Monbiot argues that feed-in tariffs for small scale renewables are regressive and a waste of money:
[The government] expects this scheme to save 7m tonnes of carbon dioxide by 2020(5). Assuming, generously, that the rate of installation keeps accelerating, this suggests a saving of around 20m tonnes of CO2 by 2030. The estimated price by then is £8.6bn. This means it’ll cost around £430 to save one tonne of carbon dioxide.
Indeed, if the government is going to provide feed-in tariffs for renewable projects, they must be the sort that can actually make a difference: multi-megawatt run-of-river hydro projects, concentrating solar stations that can put out baseload power, and the like. If the government wants a sound climate policy for homes, it should be tightening building standards, encouraging retrofits, and the like.