The IPPC commissioned Garrard Hassan to do a report on how effective wind power is at reducing carbon emissions. For those who don't know, Garrard Hassan are a leading consultancy engaged in the wind turbine gold rush. Commissioning them was a bit like asking the Jesuits to give an even handed account of Catholicism. But never mind. Here I'm going to expand on their main claim that in 2011 Wind power reduced Carbon Dioxide emissions by at least 5.5 Million tonnes. I'll leave their comedic denialist style claims regarding intermittency and reliability to another post.
Their arrogantly titled report "Beyond the Bluster" is HERE. This "peer reviewed" report (peer review panel of one) bases a great deal of its gravitas on another (quite good) report "Empirical estimates of emissions avoided from wind power generation" (good quality copy available HERE) Garrard Hassan interpret the results from this report and then grandly come to the conclusion that in 2011 at least 5.5 million tons of carbon dioxide was mitigated by wind. Of course they cannot but help to gild the lily by then going on to claim that this figure could potentially save over twice as much if all the wind power was directly offset by cycling coal plant (which, of course, in the UK it hardly ever is, and is frankly, absurd) So I think we'll stick to the optimistic 5.5 million tons and put the gilding down to a little over enthusiasm.
5.5 million tons of Carbon Dioxide. Sounds impressive. Unfortunately sounding impressive is not quite the same thing as being impressive.
Ideally wind will have displaced carbon intensive power production i.e. Coal. But in the UK it is unlikely that coal is ever directly replaced. Gas displaces coal and then cycling the CCGT plant accommodates the intermittent wind supply. But let us be nice, let's assume all of the 5.5 million tons can eventually be reflected down to a shut down of coal plant.
Now coal is almost pure Carbon. In fact 27% of carbon dioxide by weight is Carbon. So our 5.5 million tons carbon dioxide equates to a burn of 1.5 million tons coal.
Now, what size power plant does that correspond to?
Well, one ton of coal roughly corresponds to 2 MW/hr of generated electricity. (See here) So our 1.5 million tons of coal correspond to 3 million megawatt/hrs. There are 8760 hours in a year. So we can work out what size power station could provide this in a year. (3000000/8760)
So our idealistic reduction in coal burn equates to a continuous output of 340MW.
Now assuming a good coal fired power station operates with a capacity factor between 70% and 85% the 340MW equates to a single power coal fired power station of around 400 - 450MW.
So in 2011 (a windy year) the entire wind turbine fleet, at a subsidy cost of over £800 million managed to reduce carbon emissions corresponding to a single small to medium sized coal fired power station.
That is of course, if you believe the wind industry. Remember, this 5.5 million tonnes is NOT my figure it comes from Garrard Hassan - doyens of the wind industry!
This also means that the cost of offsetting that 1.5 million tons of coal comes out at well over £500 per ton in subsidy to the wind energy cartel. Every ton of coal saved from burning by wind costs us an extra £500 in subsidy on top of the actual cost of the power generation.
By chance an old clapped out, 50 year old Magnox nuclear power station in Oldbury was retired in 2012. It had been producing carbon free power for nearly half a century. Its rating? 430MW.
So every year for the last 44 years, this single small first generation nuclear power station reduced carbon dioxide emissions by roughly the same amount as the entire wind turbine fleet managed in a windy 2011.
Don't figures like that just knock you out?