Is Hornsea 2 supplying 1.4 million homes?
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Hornsea 2

Hornsea 2 has a capacity of 1,320MW, and was the largest offshore wind farm in the world on completion.

According to the Orsted website it became fully operational on 31 August 2022.

The Orsted website tells us that it is "providing enough green electricity to power 1.4 million homes" in one place, but that it "will help power over 1.4 million UK homes with low-cost renewable energy" elsewhere.

The chart on this page helps to assess those statements.

Is it really doing what its operators claim? Let's take a look at its progress.

Hornsea 2 generation

This chart shows daily energy generated by Hornsea 2.

The green horizontal line shows the energy that would be generated if the wind farm were working at a 50% capacity factor.

The red horizontal line shows the average electricity requirement of 1.4 million homes. This is based on a current Ofgem figure of 3,100kWh of electricity per year per UK household. This is set at 11.9GWh.

A 1.32GW wind farm working at name plate capacity would produce 31.68GWh per day, which explains the limit on the vertical scale.

(For a more accurate assessment of its ability to supply homes consistently we should look at a more "real time" plot of energy generated, as even summing over a day smooths and hides the variability of wind. But for the purposes of seeing how it's performing the daily totals are a good starting point.)

Hornsea 2 so far

From 1 Sep 2022 to 30 Nov 2023 it was meeting Orsted's claim (on average over the day) for about 54% of days.

So, for about 46% of days it was not achieving Orsted's claim, even on average over a day.

On almost half of days since going live, where did the power for those 1.4 million homes come from?

In 2023 so far Hornsea 2 has met the operator's claim on about half of days.

But what is most worrying is the number of days on which Hornsea 2 was generating very little electricity - if any.

On several days Hornsea 2 has taken more power from the grid than it put in. On three days it generated no power at all.