When wind and solar provide more than 55% of GB electricity, imports of power from other countries start to drop sharply. Below this level of renewables generation we usually see over 5 GW of electricity from interconnectors but when the level gets above 75% the volume is typically less than 1GW.

Not only will continued growth in renewables reduce average wholesale prices - as has been recently extensively discussed, including on this site - but it will also therefore reduce the volume of imports, improving Britain’s trade balance. A year ago, Drax estimated that electricity imports typically, cost about £250m a month, or around £3bn a year.

The pattern is shown in the chart below which logs half hourly import volumes against the share of wind and solar in total electricity generation, including imports, over 2025 so far. Up to a 55% wind and solar share, imports are typically between 4.9 and 5.6 GW of total electricity need. Then a sharp and consistent fall begins. Combined with 3-4 GW of nuclear power, high levels of renewables reduce wholesale electricity prices and make it unprofitable to import electricity via interconnectors to compete in the UK wholesale market.

Increasing amounts of renewable capacity will increase the percentage of the time that wind and solar push out imports. During 2025, wind and solar share has been above 55% only about 15% of all half hour periods. But it has been above 30% almost half of the time.

So if, as targeted, wind and solar grows by double by 2030, we can expect more and more frequent periods of very limited imports of electricity. My rough calculations suggest that typical half hourly imports are likely to fall from an average of 5.1 GW to just under 3.2 GW (assuming total electricity consumption does not change). The saving will be between £1 and £1.5bn a year.