For the past three years, National Grid has been warning that the UK’s energy generation margin has been extremely tight. With each passing year, the risk of the lights going out has been growing. This winter (2015/16) saw the margin between what we generate and what we consume fall to just 1% – causing National Grid to issue a “yellow warning” to large industrial users, who will be the first to be disconnected should demand exceed supply.
Thus far the government has been spared the embarrassment of disrupted supply because the last three winters have been among the warmest on record, helping to keep energy use to a minimum. Now, however, National Grid is predicting a negative energy margin for next winter (2016/17) due to greater than expected closures of old, coal-fired power stations together with a greater dependence upon renewables.
Both National Grid and the Department for Energy and Climate Change (DECC) claim that the UK’s energy supply is guaranteed through a combination of mothballed power stations that can be brought back on line in the event of shortages, and access to imported electricity from Europe, Norway and Ireland. But neither has factored in the potential impact of high pressure Arctic air settling over Western Europe for a fortnight or more.
Weather of this kind is far from rare, and it is characterised by little to no wind and prolonged sub-zero temperatures. During this kind of weather, wind generation is all but impossible, so National Grid would have to call on imports and attempt to start the mothballed power stations – assuming these haven’t been cannibalised to provide spare parts for existing stations. The trouble is that it is precisely this kind of high pressure Arctic weather that results in a huge increase in demand across Europe, dramatically reducing UK access to imported energy.
One of the drawbacks of the international energy grids that have developed in recent years is precisely that they provide plenty of energy when nobody else needs it, but are significantly more vulnerable to shortage when the weather gets cold. For the time being, Britain’s best hope for keeping the lights burning next winter is the hope that temperatures will keep on rising.