An expert report warns the UK of energy security in extreme weather conditions.

The UK is making significant changes to the energy grid to meet net-zero targets. This means more of our electricity will be generated by renewable energy sources such as wind, solar and hydropower. Ultimately, the future generation mix will be dominated by renewable sources as fossil fuels will be completely removed, resulting in a zero-emission grid.

However, renewable sources are reliant on weather, which can be unpredictable and always changing in the UK. With an energy system reliant on renewable sources, extreme weather could seriously threaten UK net-zero targets and energy security without the intervention of policymakers.

An independent report, produced by academics from Imperial College London for Dax Electric Insights, has shown that the UK has already been experiencing extreme weather conditions. We have had 11 days of low wind output in the first quarter of this year, the longest period in over 10 years.

Our emissions targets have been impacted as a result of this significant drop in the wind as network operators are forced to replace the loss of wind generation with gas-powered generators. Every gigawatt (GW) lost was replaced by 0.84 GW of gas as the UK 24.4 GW wind farm fell as low as 0.6 GW on 3rd March.

Although these conditions are rare, the 2021 Texas power crisis has shown us how dangerous oversight in weather conditions can be. The energy systems were unprepared in the event of an extreme cold spell which resulted in large areas of Texas left without power. To avoid this we need flexibility such as efficient energy storage.

We have been warned that we could expect to experience these long periods of low wind every 20 years on average, although weather conditions can have dramatic changes and unexpected results. This calls for urgency to secure our energy systems.

Co-Author of the report, Dr Malte Jansen, said:

“With wind and solar power set to supply half our electricity needs in the next five years, these extreme events will become much more impactful. To bridge the gap and deliver a net-zero energy system, the UK needs to invest in much more clean and flexible technologies, such as long-duration energy storage.”

With their report highlighting the importance of pumped hydro storage, the renewable energy leader Drax is proceeding with plans to develop a second underground power station alongside their existing pumped hydro storage facility in Scotland. They have shown their importance in the first quarter of the year by setting a record high daily output when wind generation was at its lowest.

Similar to long-period battery or gas storage, pumped hydro storage stores excess energy that is generated when there is more supply than demand. It can then release this energy when the demand exceeds the supply to balance out the grid and meet demand. Although this supports renewable energy storage over long periods, such plants have not been constructed since 1984.