MorganEnergy

National Grid has issued its annual winter consultation document for the UK’s gas and electricity markets. The document is available from the Ofgem web site. The outlook appears fairly bullish, although there is some concern as to when the new LNG terminals at Milford Haven (Dragon and South Hook) will begin commercial operation. The Ofgem press release quotes a reserve margin in generation of 26.8%. However, perusal of the document shows that this is based on the Seven Year Statement’s figure of 79.4 GW of contracted capacity, whereas National Grid’s operational viewpoint suggests available capacity of between 75.4 and 76.1 GW.

A theme running through the electricity sections of the report is the difficulty of predicting availability from wind generation. National Grid presents figures showing that the load factor of wind plants varies significantly through the year, but is rarely over 40%. Historical data suggests that the average availability during the winter peak should be about 35%, but the actual figure for 2007/08 was only 8%. As the volume of wind capacity on the system increases, this will become more of a concern for system operators.