The market price for electricity could climb because of a fall in the value of the pound against the euro, but also because of potentially costly complications of severing ties with EU energy markets.
Gas and electricity bills rose by £2bn in the year after the 2016 referendum result because of the plummeting value of the pound, according to a report from University College London.
This translated into an average household’s bill increasing by £35 for electricity and £40 for gas, and researchers predicted bills would climb by a further £61 every year in the years following the referendum.
Kristian Ruby, the head of pan-European trade association Eurelectric, said a no-deal exit could mean the UK faces third-party costs to use the power lines connecting Britain to European power markets, which would raise the overall cost of the energy.
Ruby said the UK might also find it more difficult to trade if it were left out of the complex pan-European trading system, and this could place a “risk premium” on UK prices.
“When you throw all rules up in the air at the same time, this lack of clarity, predictability and rule of law is what is very concerning for us,” he added.
Govt comments and echoed by National Grid, which runs the UK’s power cables, said it was “not anticipating any additional charges for inter connectors in the event of a no-deal Brexit”.
However, the plan has not been agreed by the European commission and could be cast in doubt if the UK leaves without an agreement or without paying the £39bn exit fee.