National Grid report highlights challenge in managing electricity supply and demand in summer

Out-Law News | 07 Apr 2017 | 3:51 pm | 1 min. read

National Grid has admitted that it might have to instruct some power stations, hydro generators and wind farms to reduce the amount of electricity they generate this summer in light of anticipated record low levels of demand.

In its 2017 summer outlook report, National Grid said that "levels of demand on the transmission system" have been reducing in recent years, in large part due to an increase in the generation of electricity from solar panels which feeds directly into the distribution network and "acts to reduce demand on the transmission system".

It has forecast that demand on its transmission system will peak in high summer at 35.7GW, with the lowest levels of demand likely to fall to 17.3GW. The anticipated levels of demand are lower than the peak and minimum levels of demand for electricity recorded in previous UK summers.

National Grid said, to account for falling demands at off-peak times, it "will need to curtail flexible generation this summer" and that it "may also be necessary to instruct inflexible generators to reduce their output during these periods of low demand".

Flexible generation is classed as electricity generation schemes that can "respond quickly to requests to change their output, such as interconnectors, some coal and gas units, and most large wind farms", according to National Grid.

Inflexible generators require more time to adjust the level of electricity they generate. National Grid said examples include nuclear, combined heat and power (CHP) stations, and some hydro generators and wind farms.

National Grid said that, in future, it expects to have to take more action to "manage voltage".

Phil Sheppard, director of system operations at National Grid, said that its 'demand turn up' service is one way to balance the system of supply and demand for electricity.

"In February we completed a successful tender for the demand turn up service, which offers opportunities for large energy users to voluntarily shift their energy usage in exchange for a payment," Sheppard said. "We dispatched this service for the first time in summer 2016 to help us manage periods when demand was low and generation output was high. It is just one of the tools and services we can use to balance the system during the summer."

Energy law expert Nick Shenken of Pinsent Masons, the law firm behind, said: "The growth of renewable technologies has naturally increased the flexible generation available to National Grid such that, where necessary, they can reduce supply more easily, but they could perhaps do so more competitively in the future as our network gets smarter."

"The rise of battery storage could provide additional flexibility – at Grid scale and even behind the meter – and National Grid's recent application to be allowed to hold storage assets itself may, if successful, provide another avenue whereby oversupply could be dealt with more competitively with less cost to the consumer," Shenken said.