Last year, the Biden administration set an ambitious new goal for the USA: to deploy 30 gigawatts (GW) of offshore wind capacity by the year 2030, increasing US offshore capacity more than seven hundred times over. The UK already has 15 GW of offshore wind, more than 300 times as much as the USA: and our experience should be a terrible warning to Americans.
The UK’s electricity prices are the highest since records began in 1920 and are now amongst the highest in all Europe. One reason for this is obvious: slightly less than half our electricity comes from gas-burning Combined Cycle Gas Turbines (CCGTs) and gas now costs £90 per megawatt-hour (MWh), nearly five times higher than normal. CCGTs are cheap to build (around £650m per GW) and operate. In normal times they would generate electricity at a total cost of £40 per MWh. That’s now risen to nearly £150/MWh, thanks to Vladimir Putin and his impact on the gas market.
But that’s not the whole story. The other reason why British electricity is so expensive is because we have so much wind power: particularly, so much offshore wind power. Bad though the current situation is, we would be an even worse state if we had built even more offshore wind, as the British government plans to.
As an example, the offshore wind farms Hornsea Two and Moray East were completed in 2022 with capital costs of £2.77 billionper GW and £2.75bn/GW, more than four times the cost of CCGT capacity. They’re expensive to maintain, which is not surprising since offshore windfarms have all their many generators mounted at the top of 200-metre tall masts far away from land. Estimates of maintenance costs are as high as £200m per GW installed, per annum. The nominal cost of offshore wind generation is £170/MWh – noticeably higher than that for CCGTs, even in these dire times of high gas prices.
In 2021 the UK annual grid balancing costs reached £4.19 billion, £150 per household. For context, back in 1995 when we didn’t have much wind power the balancing cost for the grid was a mere £250 million per annum. A large, and growing, contribution to these costs is constraint management, as when a wind farm producing electricity which isn’t wanted – perhaps when it is windy in the middle of the night – is paid not to put that electricity into the grid.
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