A former minister has warned the UK should brace for blackouts as a result of Britain's increased reliance on renewable energy.

       Conservative peer, Lord David Frost, said the country came "unsettlingly close" to "rolling power cuts" on Wednesday night, warning "it may happen" on the next cold night of the year.

       His claims came after the National Energy System Operator (NESO) published an alert on Wednesday urging electricity providers to boost output to avert the risk of blackouts.

       It was the first time such a measure has been taken this winter and came in a week which has seen temperatures plunge as low as -16C in some parts of the country.

       Bitterly cold temperatures have stoked demand for gas and electricity, putting strain on the system, added to by a lack of wind and solar.

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       NESO pointed out the warning didn't signal blackouts were imminent or that there was insufficient power generation to meet demand at the time.

       Data from the National Grid showed half of Britain's power was being generated from natural gas while renewables made up just 16%, according to figures cited by Sky News.

       Lord Frost, writing for the Telegraph, said the more renewables the UK relies on, the more the country's capacity won't deliver on cold dark nights and the more will have to be found elsewhere.

       He said: "There is no guarantee interconnectors will fill the gap, since cold windless nights don't stop at the UK border, and every country will look to its own needs first."

       Under reciprocal arrangements with nearby countries, Britain can take power from internconnectors to keep up with demand. France and Norway provided 10% of output on Wednesday.

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       The peer warned Brits will be forced to fork out ￡20billion a year in subsidies and maintaining grid capacity as a result of the Labour Government's plans. He dubbed the push to decarbonise the country a "dangerous and expensive insanity" which will lead the UK to "disaster".

       Frost blamed former Conservative prime minister Theresa May's administration for the current situation, but accused Energy Secretary Ed Miliband of "doubling down" on Net Zero when North America and "much" of Europe are having "serious second thoughts".

       A spokesperson from the Department for Energy Security and Net Zero said: "We are confident we will have a sufficient gas supply and electricity capacity to meet demand this winter, due to our diverse and resilient energy system.

       "Our mission for clean power by 2030 will replace our dependency on unstable fossil fuel markets with clean, homegrown power controlled in Britain – which is the best way to protect billpayers and boost our energy independence.

       "Storing energy is key to reaching our 2030 mission and through our Clean Power Action Plan we are reversing a legacy that has seen no new long duration electricity storage built for 40 years."

       According to DESNZ, NESO's Electricity Margin Notice was not unexpected and such measures form part of a standard toolkit available to manage supply and demand.

       The notice means although there is enough generation available to meet demand, NESO would like to see a larger safety cushion of spare generating capacity.