Neso said the warning is a routine measure to secure additional generation capacity and stressed there is no risk to customer electricity supplies. France's EDF also previously warned that heat is affecting output at some nuclear power stations, which could potentially limit electricity exports.
UK Heatwave Strains Grid
A national energy system operator warning is attracting attention to the pressure that extreme summer temperatures are placing on the United Kingdom's electricity network.
The UK's National Energy System Operator (Neso) issued an electricity margin notice ahead of Thursday evening's peak demand period after forecasting tighter-than-normal electricity supplies. The operator requested that power generators make additional generation capacity and flexibility available to help meet expected demand, which is being driven by the use of cooling devices like fans and air conditioners in homes and businesses.
According to Neso, the tighter electricity margins are being caused not only by higher domestic demand but also by extreme temperatures across Europe, which have reduced the availability of some power generation. Despite the warning, the government-owned operator explained that the notice is a routine mechanism used to balance the electricity system and ensure sufficient supply during periods of elevated demand. It also reassured the public that customer electricity supplies are still secure and that it will continue monitoring conditions closely.
The latest warning comes only weeks after Neso issued a similar request for electricity supplies during a previous heatwave. At the end of June, the UK recorded a provisional temperature of 37.7 degrees Celsius in Lingwood, Norfolk, which set a new June temperature record and surpassed the previous record of 35.6 degrees Celsius.
While current forecasts suggest temperatures may peak at around 34 degrees Celsius in parts of southern England, meteorologists expect the hot weather to persist for more than 10 days. This increases the strain on the electricity network over an extended period.
One consequence of these tighter electricity margins is the possibility that Neso may once again have to pay higher-than-normal prices to gas-fired power plants to guarantee sufficient electricity generation during periods of peak demand. The situation is complicated by conditions across continental Europe.
France's state-owned utility company, EDF, also warned that the ongoing heatwave is affecting several of its nuclear power stations. High river temperatures are reducing the effectiveness of water used to cool nuclear reactors, which is forcing the company to lower output at some facilities. EDF indicated that production could initially be reduced at two reactors, with additional reductions possible if the extreme weather continues.
France is an important exporter of electricity to neighboring countries, including the United Kingdom and Germany. Any reduction in French nuclear generation could therefore limit electricity exports at a time when demand across Europe is already elevated because of widespread high temperatures.
Although the national energy system operator warning does not mean that there is an imminent threat to electricity customers, it sheds some light on how frequent and prolonged periods of extreme heat are placing more pressure on energy infrastructure in Europe.
