Winter electricity margins ‘manageable’ with 2.4GW extra reserve

National Grid has procured an additional 2.4GW of balancing reserve, making the electricity margin of 5.1 per cent for winter 2015/16 “manageable".

National Grid said in its annual Winter Outlook there is an “increased likelihood” that the contingency balancing reserve procured for this winter will be called upon, but that it had the “right tools in place” to manage the system.

In June, National Grid announced it had procured 2.56GW of additional reserve, but this has fallen to 2.4GW following the withdrawal of several participants from the service.

The de-rated electricity capacity margin of 5.1 per cent is in line with National Grid’s predictions in its winter review and consultation published in July and remains “well within the reliability standard set by the government”.

This is the tightest margin since the 4 per cent margin of winter 2005/6, following a recent spate of power station closures.

For winter 2014/15, National Grid increased the de-rated capacity margin from 4.1 per cent to 6.1 per cent by finalising contracts with three power stations to provide additional reserve under supplemental balancing reserve.

The peak transmission system demand forecast has increased from last year to 54.2GW. There has been no change in generation since July.

In contrast to electricity, National Grid said gas supplies were expected to be “comfortable this year thanks to good availability of liquefied natural gas on the global market and stable flows from the North Sea and Norway”.

National Grid’s director of UK market operations Cordi O’Hara said: “Gas demand for the winter period is expected to be broadly in line with last year, showing a slight increase to 48,000.6 million cubic metres (mcm). Peak daily demand is forecast to be 465mcm.

“The maximum potential delivery of gas supplies, including from storage is 613mcm, which is significantly higher than the peak demand forecast.”