Britain’s rapid expansion of solar power is increasing the need for energy storage and flexible generation, strengthening the relevance of assets that can supply electricity when solar output falls.
A new Electric Insights report says growing solar capacity is cutting the need for gas-fired generation during daylight hours. However, the system still faces pressure in the evening, when solar production drops at the same time as electricity demand rises.
Britain added 2 GW of solar capacity over the past year, while solar generation reached a record 15.4 GW in April. During one half-hour period, zero-carbon sources supplied 98.8% of electricity demand.
The issue is timing. Solar output is concentrated during the day, while demand remains high into the evening. In June, wholesale electricity prices after 7pm were more than double their level at 2pm. That price difference highlights the value of technologies that can store electricity when supply is high and release it later. Batteries, pumped storage hydro and flexible generation can all help reduce the gap between daytime renewable production and evening demand.
Hot weather has added further pressure to the system. Wholesale electricity prices rose above £500/MWh during June, the highest level recorded for that month. The National Energy System Operator also issued its first summertime Electricity Margin Notice.
Higher temperatures can increase power demand through cooling while reducing the efficiency of electricity networks and some generation assets. Low wind generation during evening periods can make the system more dependent on flexible power sources.
This is relevant to Drax because its UK portfolio includes biomass, hydro, pumped storage and open-cycle gas turbine generation. These assets can provide electricity when intermittent renewable output is lower and can support the wider stability of the power system.
Pumped storage could become particularly important as solar capacity increases. The technology allows electricity to be stored when supply is abundant and released when demand rises, directly addressing the growing difference between daytime and evening power conditions.
Drax Group plc (LON:DRX), trading as Drax, is a power generation business. The principal downstream enterprises are based in the UK and include Drax Power Limited, which runs the biomass fuelled Drax power station, near Selby in North Yorkshire.
