Wind power for 1.2m homes is wasted because of lack of storage
Enough wind power to supply 1.2m homes a day was wasted over winter because there is no capacity to store extra energy generated on gusty days, according to new research.
National Grid’s electricity system operator asked wind turbines which were expected to generate about 1.35 terawatt-hours of electricity between October and January to switch off instead because they were not needed to meet demand at the time, according to the consultancy Stonehaven.
Meanwhile, gas-fired power turbines burned an estimated 65 terawatt-hours of gas over the period when wind speeds were lower – costing an estimated £60bn.
It came as National Grid asked two British coal-fired power plants to warm up in case they were needed for back-up electricity on Tuesday during a predicted cold snap. It stood them down by late Monday afternoon.
Rupert Pearce, chief executive of electricity storage business Highview Power, which commissioned the Stonehaven analysis, said more storage capacity was needed to prevent wind power being wasted.
He said: “Renewable energy storage is essential to powering a cleaner, cheaper, always-on Britain.
“By capturing and storing excess renewable energy, which is now the UK’s cheapest, most secure and most abundant form of energy, we can power Britain’s homes and businesses with renewable green energy, taking millions of tonnes of carbon out of the atmosphere and ending a culture of reliance on expensive foreign imports.”
Electricity supply and demand have to be constantly matched, meaning wind turbines can be paid to switch off if it is too windy, or if there is not enough capacity on cables to move the electricity to where it is needed.
Efforts are underway to develop more storage capacity so that electricity from windy periods can be stored and saved for when it can be used, instead of switching turbines off.
Current storage methods include lithium batteries and pumped hydro-electric storage.
Highview Power is developing an alternative which uses electricity to liquify air. When power is needed, the air is turned back into gas and drives a turbine.
There is heightened pressure on Britain’s electricity supplies this winter amid a spate of nuclear power station closures in the UK and outages in France’s fleet.
Britain typically imports nuclear electricity from France to meet peak demand during winter, but its ability to do this is more limited given the constraints there.
National Grid asked for coal plants in Ratcliffe-on-Soar, Nottinghamshire and West Burton, Lincolnshire, to be warmed so they can come online on Tuesday if other power providers cannot meet demand. Shortly before 5pm it said they would not be needed, “following further assessment of operational margins”.
Gas is typically used to generate about 40pc of the UK’s electricity across the year, as well as heat the vast majority of homes.
Both gas and wind have each generated about 34pc of Britain’s electricity over the past four months, according to figures from National Grid.