Is GB wind achieving its forecasts?
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Wind power in GB

According to the National Grid ESO wind power will become the primary source of electricity in GB in coming years.

Projected wind capacity and generation suggest that it can indeed produce much more electricity than it does now.

However, these projections are based on a set of assumptions that are proving to be totally false. We will deal with these assumptions on other pages. On this page we will look at the reality of the National Grid ESO's most recent forecasts and the actual performance of wind in GB.

The forecasts we use here are contained in the FES documents for the years referred to, and in particular the relevant data workbooks.

The reported performance in each case is from the Elexon site, which is the official reporting source for the GB National Grid.

What's happening in 2023?

The National Grid ESO forecast for GB Grid wind in 2023 is 77.2TWh, which is only a very slight increase on the forecast for 2022. In FES2021 the forecast for 2023 was over 90TWh, so National Grid ESO have reduced their forecast very considerably.

You can see progress against that forecast in the chart.

What happened in 2022?

Over a few years leading to 2021 the National Grid ESO forecast for GB Grid wind in 2022 increased to 88.8TWh. This was based on projections of capacity and load factors.

However, part way through 2022 National Grid ESO released FES2022, and the forecast was reduced to 76.54TWh, a reduction of almost 14%.

Now that we have the total for 2022 we can see that actual performance fell well short of even the reduced forecast.

The total generated on the GB Grid was 61.7TWh

Wind variability in 2022

Alongside the issue of failure to generate the volume of energy forecast, the issue of variability was fully evident in 2022.

The chart shows the daily generation and clearly demonstrates the huge range in performance from day to day.

In order to meet demand GB still relies on dispatchable sources (primarily gas) to "fill the gaps" when wind is not performing.

In fact the situation is considerably worse than indicated by this chart. If a chart showing generation in 5 minutes or 30 minute intervals is drawn the high and low extremes are even more evident.

What happend in 2021?

With increased wind capacity in 2021 you would expect generation to increase accordingly, but it didn't. What wind did in 2021 was to demonstrate how unpredictable it is, and how we have no control over how much wind there is to use.

Early in the year wind was soon "behind schedule" in generation, and it never caught up, finishing the year with a significant deficit against forecast.

(In FES 2020 the 5 year forecast for total onshore and offshore wind generation in 2021 was 62.23TWh. The total generated was just under 49TWh.

What happend in 2020?

The dashed red line shows the forecast wind generation for the year levelised over the year, i.e. representing how a plot of the generation would look if it were evenly spread over the year.

The green line shows the actual generation over the year. A fairly normal pattern for GB is seen. There is more wind generation in winter months so wind exceeded the levelised forecast. During summer the wind produced less electricity, so the green line dropped to be closer to the red line. Later in the year wind generation picked up and by the end of the year the forecast was achieved.

(In FES 2019 the 5 year forecast for total onshore and offshore wind generation in 2020 was 52.3TWh. The total generated was 54.7TWh.