The potential for growth, most analysts argue, is clear. But bottlenecks and political setbacks, not to mention technological glitches, will create many bumps in the road ahead. Indeed, fears that the most euphoric investors were overlooking such obstacles seem to have contributed to a sharp fall in clean-energy stocks earlier this year-although they have since recovered much of the lost ground. Such jitters caused several green-energy firms to cancel planned flotations. “There’s legitimate debate about a couple of segments,” says Keith Raab, boss of Cleantech Venture Network. In some instances, valuations accorded to firms with no profits-and little chance of making any soon-were reminiscent of the excesses of the dotcom bubble. As Douglas Lloyd, of Venture Business Research, puts it, “There’s too much money chasing too few opportunities. How is it possible that this many solar companies are going to succeed? They’re not.”

Most shocking of all is new evidence that the need to switch on and off base load fossil fuel power plants, to provide back up for unreliable wind turbines, actually gives off more carbon emissions than keeping them running continuously, thus negating any carbon savings from wind. Alas, only when our governments have allowed thousands more turbines to disfigure Britain’s countryside, not least by their grotesque bending of the planning rules, will the futility of the ‘great Wind Scam’ finally be recognised.