In the end, the solar eclipse did not cause the electricity grid to flicker. The early drop-off in solar generation was manageable, just as the National Energy System Operator (Neso), the state-owned body responsible for keeping the lights on, predicted. Gas-fired generators still had to be paid nose-bleed prices to fire up, and power via high-voltage interconnectors to continental Europe was also expensively sourced. But the system worked.
A summer of heatwaves, however, has highlighted European grids’ reliance on those interconnectors – including seven between the UK and the continent – in an age of extreme weather and greater use of intermittent renewables. On Thursday, another low-wind “heat dome” day, a fifth of power to the British grid was coming from the continent at 10am. Cables from France alone were meeting 11%, or 3.54 gigawatts, of demand, or more than twice as much as the output at that time from the UK’s entire fleet of windfarms.
The economic appeal of interconnectors is obvious: cross-border transfers should boost security. For Britain, as on Thursday, it can sometimes be cheaper to source from the continent, especially from France’s nuclear-dominated system, than use domestic gas-fired generation. And on sunny windy days when the UK’s renewables are producing a surplus, the flow can be in the other direction. Over the course of a full year, the UK currently imports roughly a tenth of its electricity.
The politics, on the other hand, have rarely looked messier.…
