The Academy study performed a “stress test” on the winter capacity margin forecasts to see how the electricity system would cope with severe adverse events (low wind, cold weather, and unplanned plant outages) when combined with the closure of 11.5GW of coal and oil-fired plants under the large Combustion Plant Directive (LCPD) and the mothballing of gas-fired plants.
The report warned that in the winter of 2014-15 a combination of the three severe adverse events would increase the chances of power outages due to a “significant reduction in the resilience of the system”.
Dr John Roberts, chair of the working study, undertaken at the request of the Prime Minister’s Council for Science and Technology, said: “Although the combined closures are not expected to bring the total available electricity capacity below the predicted peak demand, a reduced margin in the power available at any given time would reduce the flexibility of the system and increase the chances that otherwise manageable failures could jeopardise the country’s power supply.
“The longer a low capacity margin persists, the greater the chance of experiencing a combination of challenging events during that time.”
The report calls for interim measures up to 2015 to prevent the withdrawal and mothballing of gas-fired plants, and to bring forward more demand-side response mechanisms.
It also urges for the Electricity Market Reform (EMR) process to be resolved “as quickly as possible” to attract new investment to the UK that is “essential” to maintain security of supply.
The report said: “The uncertainty of EMR may be masking the signals that a well functioning market would otherwise give in anticipation of the forthcoming LCPD closures.
“It is this coincidence of factors that leads us to believe that the government should be mindful of the possibility of capacity shortages during the next five years.”