Despite overblown promises, offshore wind power is as meaningless as its onshore cousin. Centuries of sailing the high seas provided the clue: when the wind stops blowing, the boat ain’t going.

So, if seafarers had nothing but curses for their days in the doldrums, why would offshore wind power be any different?

Not only is offshore wind power just as fickle as the onshore kind, it is insanely expensive. Not least due to the exponential increase in operations and maintenance costs, thanks to the salt-laden marine environment in which these things operate offshore.

But, as the pitch goes, the insane cost is purportedly offset by “wind that is always blowing out at sea”.

Paul Homewood tackles that grand mistruth below.

How Volatile Is Offshore Wind?
Not a Lot of People Know That
Paul Homewood
17 March 2022

It is commonly claimed that the wind is much more constant and reliable in the North Sea and around Britain’s coasts than it is inland. “The wind always blows!”

But how true is this?

The Low Carbon Contracts Company, who manage the CfD system, provide daily data for generation by all generators with contracts. In particular there are sixteen offshore wind projects on their database, which offer a good geographical spread. They account for about a half of total UK offshore generation:

I have analysed January 2022 data for these, and below is the daily output:

https://www.lowcarboncontracts.uk/data-portal/dataset/actual-cfd-generation-and-avoided-ghg-emissions

Far from being “constant”, we can see that wind power is extremely volatile. Daily production ranges from 8322 to 84984 MWh, with a monthly average of 49245 MWh.

There were thirteen days when output was below 45000 MWh, in other words more than 10% below average.

There were seven days in the month when it failed to reach 25000 MWh. The average for those days was 17000 MWh, equivalent to them working at 15% of capacity. The worst day, when output was 8322 MWh, offshore wind was only operating at only 7% of capacity.

Bear in mind as well that this is winter, not summer when you might expect low wind speeds.

We have been promised 40 GW of offshore wind by 2030, but in reality the most we can actually rely on is 3 GW.
Not a Lot of People Know That

Another wind power myth goes up in smoke.