13 May 2017 |Matt Ridley| The Spectator
We urgently need to stop the ecological posturing.
The Global Wind Energy Council recently released its latest report, excitedly boasting that ‘the proliferation of wind energy into the global power market continues at a furious pace, after it was revealed that more than 54 gigawatts of clean renewable wind power was installed across the global market last year’.
You may have got the impression from announcements like that, and from the obligatory pictures of wind turbines in any BBC story or airport advert about energy, that wind power is making a big contribution to world energy today. You would be wrong. Its contribution is still, after decades — nay centuries — of development, trivial to the point of irrelevance.
Even in rich countries playing with subsidised wind and solar, a huge slug of their renewable energy comes from wood and hydro, the reliable renewables. Meanwhile, world energy demand has been growing at about 2 per cent a year for nearly 40 years. Between 2013 and 2014, again using International Energy Agency data, it grew by just under 2,000 terawatt-hours.
If wind turbines were to supply all of that growth but no more, how many would need to be built each year? The answer is nearly 350,000, since a two-megawatt turbine can produce about 0.005 terawatt-hours per annum. That’s one-and-a-half times as many as have been built in the world since governments started pouring consumer funds into this so-called industry in the early 2000s.
At a density of, very roughly, 50 acres per megawatt, typical for wind farms, that many turbines would require a land area greater than the British Isles, including Ireland. Every year. If we kept this up for 50 years, we would have covered every square mile of a land area the size of Russia with wind farms. Remember, this would be just to fulfil the new demand for energy, not to displace the vast existing supply of energy from fossil fuels, which currently supply 80 per cent of global energy needs.
Their effectiveness (the load factor, to use the engineering term) is determined by the wind that is available, and that varies at its own sweet will from second to second, day to day, year to year.
Matt Ridley discusses wind power