The lights would stay in a renewable-based grid even during a protracted period of low-wind speeds, a new report has predicted.

The study, carried out by consultancy New Resource Partner for the Energy and Climate Intelligence Unit (ECIU), modelled how the electricity grid would cope with an increased dominance of variable wind and solar power.

It examined the consequences of half of all UK electricity being generated by wind and solar by 2030.

The modelling found that this future grid would maintain energy security even during a three-week “wind lull” in mid-winter when electricity demand peaks.

And it says less back-up gas generation capacity would be needed than the UK currently possesses.

The peaks in demand would be smoothed out by a combination of shifting demand and more sophisticated energy storage. In addition, the flexible deployment of gas-fired power stations and trade with Europe via interconnectors would supplement the UK’s baseload capacity.

“Even the most exaggerated becalming of the wind is no threat to reliability if sufficient smart, flexible energy infrastructure is present,” the report states.

The model also compares the costs of the 50 per cent wind and solar generation scenario with an alternative UK energy system in which gas capacity increases to cover demand once the existing pipeline of renewable projects is complete.

It finds that the cost of both systems is broadly comparable, with the high-renewables system initially more expensive but becoming cheaper by 2030.

And it says a heavier dependence on renewables is likely to be even cheaper by this point thanks to a combination of continuing falls in wind and solar capacity, increased competition from flexibility mechanisms like storage and advanced demand-shifting, as well as additional revenues renewable projects might raise from selling surplus electricity for export from the UK or manufacturing hydrogen.

The report concludes that traditional approaches to balancing electricity supply and demand are “no longer appropriate”.

It recommends that the government should build a market for flexible mechanisms, encourage more “real-time” trading of electricity to unlock flexibility in the system, make greater use of interconnectors to trade electricity with Europe and step up efforts on battery research.

It says: “The establishment of a flexibility market that is accessible to all forms of flexible power according to their merits is the most important early task.

“Provided that the market is well designed to reward flexibility, then the spectre of the wind lull blows away, even as GB comes to rely on these technologies for the majority of its energy needs.”

Richard Black,director of the ECIU, said that the report backed up the case for more investment in renewable energy.

He said: “Investing sensibly in these mechanisms is critical as we develop an energy system fit for the 21stCentury that is clean, reliable and cost-effective.”