Surprise, surprise: Wind turbines do lower carbon emissions

Counter-intuitive thinking is counter-intuitive for a reason.

Climate sceptics have long made the counter-intuitive claim that wind turbines don't actually reduce carbon emissions, but data analysed by the Guardian's environment blog suggests that as well as being counter-intuitive, it's just plain false.

The claim the Guardian's Chris Goodall and Mark Lynas investigated relies on the fact that wind power fluctuates with the weather. As a result, when the windspeed drops, gas power stations have to be spun up to provide electricity instead. It has to be gas, because other low-carbon sources of energy either have the same fluctuations as wind, or, like nuclear power, essentially can't be turned off.

The sceptics argue that the need to rapidly turn on the gas generators means that a type of power station known as a "gas-fired open cycle turbine" (OCGT) has to be used. Their key point is that these turbines, which are capable of being put into use extremely quickly, are less efficient than another type of gas generator, a "combined cycle gas turbine" (CCGT). The need to pick up the slack left by wind power, they say, means that so many of these inefficient turbines are used that carbon emissions actually go up compared to the scenario where all the electricity is generated with the more efficient CCGT type.

The Guardian's blog contains a lot of stats taken straight from the National Grid, all of which confirm the intuitive beliefs: wind power replaces fossil fuels. But for the specific claim that it still results in higher carbon emissions, the operative paragraph is the following:

Their arguments are not borne out by current statistics, however. If the sceptics were right, the recent windy conditions would have seen considerable use of less-efficient OCGT as wind input to the grid ramped up and down. In actual fact, during the entire June-September period, OCGTs and equally dirty oil-fired stations produced less than one hundredth of one percent of all UK electricity. In total they operated for a grand total of just nine half hour periods in the first 19 days of the month – and these periods had nothing to do with changing windspeeds.

In other words, the mechanism the sceptics suggested might be at work isn't. The authors go into greater detail about why that is, as well. In essence, it comes down to the fact that wind power isn't actually all that unpredictable. It comes and goes, but we usually have a good few hours warning about when it's going to die down; and it's spread throughout the country, allowing even more flattening of the peaks and troughs in supply.

The bigger reason for having to suddenly spin up big generators isn't sudden drops in supply, but sudden peaks in demand. Take, for example, a World Cup match, where England have made it through to sudden death penalties. The National Grid know there will be a spike in power consumption the minute the match ends, as people get up to put the kettle on – but they can't know when that spike will be until mere seconds before it actually happens. That sort of load will always be problematic to supply with renewables – but it's not much less problematic to supply with fossil fuel either.

Wind turbines. Photograph: Getty Images

Alex Hern is a technology reporter for the Guardian. He was formerly staff writer at the New Statesman. You should follow Alex on Twitter.

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No, David Cameron’s speech was not “left wing”

Come on, guys.

There is a strange journalistic phenomenon that occurs when a party leader makes a speech. It is a blend of groupthink, relief, utter certainty, and online backslapping. It happened particularly quickly after David Cameron’s speech to Tory party conference today. A few pundits decided that – because he mentioned, like, diversity and social mobility – this was a centre-left speech. A leftwing speech, even. Or at least a clear grab for the liberal centre ground. And so that’s what everyone now believes. The analysis is decided. The commentary is written. Thank God for that.

Really? It’s quite easy, even as one of those nasty, wicked Tories, to mention that you actually don’t much like racism, and point out that you’d quite like poor children to get jobs, without moving onto Labour's "territory". Which normal person is in favour of discriminating against someone on the basis of race, or blocking opportunity on the basis of class? Of course he’s against that. He’s a politician operating in a liberal democracy. And this isn’t Ukip conference.

Looking at the whole package, it was actually quite a rightwing speech. It was a paean to defence – championing drones, protecting Britain from the evils of the world, and getting all excited about “launching the biggest aircraft carriers in our history”.

It was a festival of flagwaving guff about the British “character”, a celebration of shoehorning our history chronologically onto the curriculum, looking towards a “Greater Britain”, asking for more “national pride”. There was even a Bake Off pun.

He also deployed the illiberal device of inculcating a divide-and-rule fear of the “shadow of extremism – hanging over every single one of us”, informing us that children in UK madrassas are having their “heads filled with poison and their hearts filled with hate”, and saying Britain shouldn’t be “overwhelmed” with refugees, before quickly changing the subject to ousting Assad. How unashamedly centrist, of you, Mr Prime Minister.

Benefit cuts and a reduction of tax credits will mean the Prime Minister’s enthusiasm for “equality of opportunity, as opposed to equality of outcome” will be just that – with the outcome pretty bleak for those who end up losing any opportunity that comes with state support. And his excitement about diversity in his cabinet rings a little hollow the day following a tubthumping anti-immigration speech from his Home Secretary.

If this year's Tory conference wins the party votes, it’ll be because of its conservative commitment – not lefty love bombing.

Anoosh Chakelian is deputy web editor at the New Statesman.