In its latest interim management statement, issued this week, SSE reported that “weather conditions” during April, May and June contributed to a full 30 per cent drop in electricity output from its wind farms, hydroelectric facilities and Slough biomass heat and power plant. Output from those sources fell to 700 gigawatt-hours during that period, compared to the 1,000 gigawatt-hours generated during the last quarter of 2009.

While SSE didn’t elaborate on those “weather conditions,” one factor certainly had to be the fact that the first half of 2010 saw the “driest first six months of the year for 100 years,” according to the UK’s Met Office. And, as the climate continues changing, Britain can expect that type of situation to become more common, the agency warns.

If hydroelectric power sources are threatened by climate change, wind energy’s greatest shortcoming is its great variability, Lovelock warns in his latest book, The Vanishing Face of Gaia:

“Used sensibly, in locations where the fickle nature of wind is no drawback, it is a valuable local resource, but Europe’s massive use of wind as a supplement to baseload electricity will probably be remembered as one of the great follies of the twenty-first century … ,” he writes.

Lovelock argues the only clean energy sources that make sense for society are nuclear and solar thermal energy. All the rest aren’t viable without heavy injections of government subsidies and green cheerleading, he says.

Lovelock acknowledges he sometimes takes a bit of hyperbolic licence to make his points — as when he warned that global warming will lead to a die-off of billions of humans this century, resulting in only a “few breeding pairs of people” left in the Arctic. But does he have a point here? Is the bit of news from SSE a warning sign that we’d be better off by aggressively developing nuclear and concentrating solar power (such as that proposed in the Desertec project), and forgetting more intermittent clean-energy sources?