“But the increasing frequency of these warnings should concern us.”
She said that “the underlying problem is Britain’s growing reliance on weather-dependent electricity generation”.
Although the country has plenty of wind generation capacity, its output can fall dramatically when the weather turns.
Solar power is less effective during winter and disappears at night.
While Britain’s gas fleet could currently bridge the gap, much of it was reaching the end its operational life, she said.
She warned: “Britain is losing reliable generating capacity as older gas and nuclear plants approach retirement, without sufficient firm replacements being built.”
A second solution – imported energy through interconnectors – was only effective if neighbouring countries were not suffering the same weather conditions, she said.
But recent weather patterns had extended across north-western Europe, making imports more expensive and less dependable.
Previously, Britain had relied on dispatchable power, largely from gas. This can be fired up as and when required.
But renewables have changed the mix and, under Labour’s Clean Power plan, it is moving towards a clean energy grid, with the goal of having 95 per cent of electricity coming from clean sources by 2030.