There you go. If like me you always had a hunch that Germany and England going mad with installing solar cells on buildings made no sense at all because, well, it's hard to imagine the sun giving you a sunburn in England, let alone contributing power to your house, it turns out George Monbiot agrees completely.
He does note, though, that PV on the roof makes more sense in areas where peak power demand does tend to occur in summer on sunny days (for airconditioning). In England (and I assume Germany) however:
"..peak demand takes place between 5pm and 7pm on winter evenings. Do I need to spell out the implications?"George is going off about the UK just setting high feed in tariffs, just at the time Germany is realising they can't be sustained. He writes about the UK:
On Germany:It expects this scheme to save 7m tonnes of carbon dioxide by 2020. Assuming – generously – that the rate of installation keeps accelerating, this suggests a saving of about 20m tonnes of CO2 by 2030. The estimated price by then is £8.6bn. This means it will cost about £430 to save one tonne of CO2.
Last year the consultancy company McKinsey published a table of cost comparisons. It found that you could save a tonne of CO2 for £3 by investing in geothermal energy, or for £8 by building a nuclear power plant.
By 2006 its generous feed-in tariffs had stimulated 230,000 solar roofs, at a cost of ¤1.2bn. Their total contribution to the country's electricity supply was 0.4%. Their total contribution to carbon savings, as a paper in the journal Energy Policy points out, is zero. This is because Germany, like the UK, belongs to the European emissions trading scheme. Any savings made by feed-in tariffs permit other industries to raise their emissions.Good reading.