Utility Week

18 | NOVEMBER 2022 | UTILITY WEEK Electricity Analysis How likely are blackouts? National Grid says it is "cautiously confi dent" about the supply of energy this winter. Tom Grimwood explores the key takeaways from its electricity and gas Winter Outlooks. T he annual publication of National Grid Electricity System Operator's (ESO's) Winter Outlook is always keenly awaited by the industry and assorted energy geeks. However, this year's report cuts through to the public and media in an unprecedented way. The question on everyone's lips is, will there be power cuts this winter? In a highly technical, forward-looking report, the answer was never going to be straightforward, and the ESO concludes it is "cautiously conƒ dent" there will be adequate supply margins. However, it admits there is a risk it may need to cut power supplies to some customers this winter if gas shortfalls leave generators without fuel. In its base case, the ESO says it expects peak underlying demand during an average cold spell to total 59.5GW, including an oper- ating reserve of 1.2GW. A total of 101.2GW of generation, de-rated to 57.5GW, is expected to be available to meet this demand, plus 8.4GW of net interconnec- tor imports, de-rated to 5.7GW. This would leave Britain with a de-rated supply margin of 3.7GW, or 6.3%, represent- ing a slight decrease when compared to last year's forecast of 3.9GW or 6.6%. The ESO says this equates to a loss of load expecta- tion (LOLE) of 0.2 hours per year. Given concern over the impact of Rus- sia's invasion of Ukraine on energy sup- plies in Europe, the ESO also modelled two additional scenarios re™ ecting the risks of reduced electricity imports via interconnec- tors and shortages of gas. The ƒ rst scenario assumes there are no electricity interconnector imports from France, Belgium and the Netherlands, but 1.2GW of imports from Norway and 0.4GW of exports to Northern Ireland and Ireland. In this case, the ESO says it would deploy both the 2GW of coal generation that has been kept online as part of its winter con- tingency service and the 2GW of demand reduction it expects to be available through the new demand ™ exibility service it has been developing in recent months. It says this would result in a de-rated supply margin of 3.3GW, or 5.7%, equating to a LOLE of 0.5 hours per year. Even with reduced take-up for the demand ™ exibility service, the ESO says it expects supply margins to remain without the gov- ernment's reliability standard of a LOLE of 3 hours per year. However, on days of both high demand and low wind output, the ESO says there may be a need to interrupt sup- plies to some customers for limited periods. The second scenario additionally assumes that 10GW of combined-cycle gas turbine generation is unavailable over a two- week period in January due to insuœ cient gas supplies. In this scenario, the ESO says the contin- gency coal generation and demand ™ exibility service would be insuœ cient to prevent a supply shortfall, meaning it may be neces- sary to initiate planned, controlled and tem- porary load-shedding under the Electricity Supply Emergency Code. "In the unlikely event we were in this sit- uation, it would mean that some customers could be without power for pre-deƒ ned peri- ods during a day – generally this is assumed to be for 3-hour blocks," the ESO explained. Rise in gas demand predicted In the Gas Winter Outlook released by the gas system operator, National Grid says it expects total gas demand over the winter to total 53.1 billion cubic metres (bcm), up from 51.9 bcm during the winter of 2021/22. The increase is primarily due to increased demand for power generation, which is expected to rise from 10.1 to 12.3 bcm as more power is exported to France. Demand from other users is expected to fall slightly as they respond to the current high prices. Gas from the UK continental shelf and Norway are expected to remain the main sources of supply, with the former pro- jected to range between 68 and 117 million cubic metres per day (mcm/d) and the latter between 34 and 141 mcm/d. National Grid notes that Britain has one of the largest capabilities in Europe for the re-gasiƒ cation of liqueƒ ed natural gas (LNG), totalling 141 mcm/d, meaning the country will be well placed to receive cargoes if prices are competitive. It says Britain will also be able to import up to 125 mcm/d via interconnectors with Europe, noting that nearly 20 bcm of extra LNG import capacity is expected to be brought online in northwest Europe this win- ter as a result of the arrival of ™ oating storage and regasiƒ cation units at Eemshaven in the Netherlands and Brunsbuettel in Germany. National Grid says that up to 117 mcm/d could be withdrawn from domestic gas stor- age, with stocks currently at around 1.6 bcm – the highest level at this time of the year in the last ƒ ve years. These ƒ gures do not cover Centrica's Rough gas storage facility, which recently resumed partial operation. Prudent action Commenting on the reports, ESO executive director Fintan Slye says: "Under our base case, as set out in the Winter Outlook, we are cautiously conƒ dent that there will be adequate margins through the winter period. "As an expert and responsible operator of Great Britain's electricity system, it is incum- bent on us to also factor in external factors and risks beyond our control like the unprec- edented turmoil and volatility in energy mar- kets in Europe and beyond." He continues: "Our illustrative scenarios outline how we would respond to any chal- lenges around interconnector availability and potential impacts to gas supplies for power generation. We've engaged with and continue to work with the National Grid Gas System Operator, system operator counter- parts in Europe, government, the energy regulator and the energy industry. "We've also taken prudent action in agreeing winter contingency contracts for coal and developing our innovative demand ™ exibility service to complement the robust set of tools we already use to balance the electricity system every day." Tom Grimwood, news editor

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