National Grid ESO is confident there will be no electricity supply issues this winter despite capacity margins tightening due to generation outages and plant closures.
In its winter outlook report, National Grid ESO said there was “no threat” to security of supply, partly as demand for electricity could fall by around 5% compared with last winter as Covid-19 measures continue to impact.
The lower demand is forecast to provide a 4.8GW margin - 8.3% of the total supply – although this is less than the 7.8GW forecast last winter.
“System margins aren't quite as high as last winter but remain well within the Reliability Standard set by the Government under all COVID-19 scenarios,” said the report.
As its “central operational scenario”, the system operator has pencilled in an overall level of demand suppression of 5% from anticipated pre-COVID demands. However, it has also modelled additional scenarios for transmission demand, including a 11% peak fall if the country returns to a full lockdown although it said it believes it is very unlikely that would persist for more than a month.
Roisin Quinn, Head of National Control at the ESO, said: “While we’re anticipating recently reimposed lockdown measures reducing national demand, the higher demand we tend to see over winter means we’re not expecting to see the same operability challenges we did over summer as a result.”
Quinn said whatever the outcome of Brexit negotiations, the system operator expects to be able to “reliably manage electricity flow to and from the continent without interruption”.
The winter forecast came as the ESO last week warned of tight supply margins over the coming days, amid very low wind output and higher demand.
“Unusually low wind output coinciding with a number of generator outages means the cushion of spare capacity we operate the system with has been reduced,” it said on Twitter.
“We’re exploring measures and actions to make sure there is enough generation available to increase our buffer of capacity.”