The amount of spare capacity in the UK electricity network has fallen once again, according to the latest Winter Outlook report published by the National Grid.
The capacity margin for electricity has fallen to 4.1%. In 2010 the figure was closer to 15%. It is calculated based on the anticipated demand and the capabilities of the grid to serve that demand.
Despite the drop, the Department of Energy and Climate Change (DECC) has moved to dispel fears of winter blackouts.
“We have taken action to make sure our energy needs will be met this winter,” said Matthew Hancock, business and energy minister.
“We have given National Grid new tools they need to meet energy demand this winter and our working through a long-term plan to turn around a legacy of underinvestment in our energy sector. This government has made sure homes and businesses across the country will be energy secure,” said Hancock.
“But there’s more to do to complete our infrastructure plan and further strengthen our energy security. This is part of a broader of our broader strategy to support domestic supplies of electricity like renewables, shale gas and nuclear,” he added.
The GMB union, which represents energy workers, was highly critical.
“This very tight margin shows that government energy policy is in disarray. If there is a cold snap this winter the only way to keep the lights on is to shut down large swathes of British industry. This isn't a policy it is a shambles,” said Gary Smith, GMB national secretary for energy.
The latest figures also emboldened calls for a smarter, more flexible grid.
The Electricity Storage Network (ESN) explained what role its industry could play in dealing with the challenge posed by capacity margins.
“Capacity margin is always going to vary – it depends on both estimates of available capacity and prediction of demand. Too much margin represents additional costs for the system, which are passed on to consumers. Too little margin represents increased risk, risk drives up uncertainty, and eventually drives up prices, increasing costs for the consumers,” a statement by ESN read.
“Electricity storage is a better way of improving plant margin – it can be used to supplement peak capacity when required, (typically for the winter peak) and improves the utilisation of other plant on the system, not only by providing capacity, but also flexibility.”
Andrew Jones, managing director of power engineering firm S&C Electric said ongoing grid improvements and the use of smart technology could negate some of the impact of falling capacity margins.
“These smart technologies improve the capabilities of the electricity network by providing additional capacity and flexibility for supporting the grid at peak times,” said Jones.