National Grid said it expects low demand for electricity this summer as small-scale renewables output increases. It also warned operators of large gas and nuclear power stations there could be times when there is more generation than needed.

It issued the warning as part of its summer outlook report, and said peak transmission system demand for high summer (June-August) was forecast at 33.7 gigawatts (GW) and the summer minimum at 17 GW.

The UK electricity system operator forecast demand on the national transmission network would fall close to record lows because of the growing supply of power from small solar and wind farms which bypass the grid.

Summer electricity demand from the grid has been falling over the past few years partly due to a rapid increase in the amount of solar power generation on people’s homes and factory roofs.

Lower overall electricity demand, along with increased renewables generation, means there is less need for gas-fired electricity generation.

“We may need to take more actions to curtail generation and possibly instruct inflexible generators to reduce their output in order to balance the system,” the report said.

It predicts similar gas supply and demand patterns to last summer, with demand only around 30 per cent lower than the winter peak, but one of the highest volumes of maintenance on the gas transmission system to date at the same time.

The report said there will be 1.8 bcm of gas demand for storage sites, compared to demand of 2.5 bcm last summer.

“Increased supply and demand variability caused by these periods of low demand and high levels of renewable generation can create operability challenges,” it said. “As a result, we may need to take more actions to curtail generation and possibly instruct inflexible generators to reduce their output in order to balance the system.”

Gas is traditionally stored during the summer months to be used during winter when demand and prices are higher, but last year’s closure of Britain’s largest gas storage site Rough means less gas can be stored at present.

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