National Grid issued its first capacity market notice on Monday, warning of a potential capacity crunch in early evening.
Grid issued the warning just after midday, alerting generators with contracts to provide power when the system is short over winter, to standby.
Capacity market warnings are issued automatically when predicted supply over demand falls below 500MW. Providers are given four hours’ notice.
The system operator predicted demand at 4.30pm to be around 44.3GW, with supply at around 44.5GW.
The call, which was cancelled from 7PM, will likely be repeated several times over winter and is one of a number of tools National Grid has its disposal to ensure the lights stay on.
However, the inaugural notice follows new proposals from the department of business, energy and industrial strategy to change the rules of the capacity market, which may have significant impacts upon small generators that currently participate in the scheme.