Eight nuclear stations in the UK owned by EDF Energy produced a total of 60TWh of low carbon electricity last year – the highest output for seven years.

The energy firm reported the amount was almost 50% higher than the previous year and is enough to power half of the UK’s households. It claims the output also avoided almost 41 million tonnes of carbon emissions, which would have been produced if the same amount of electricity had been generated by fossil fuels – equivalent to removing 60% of all UK cars off the roads.

EDF Energy said the “exceptional performance” is due to its £300 million investment in the power stations on top of £350 million spent on plant operations every year. It claims investment in skills and training has also helped maintenance teams plan and carry out work “more effectively” and cut the number of unplanned outages.

Vincent de Rivaz, Chief Executive of the firm said: “The exceptional performance of EDF Energy’s nuclear power stations is helping to keep the lights on in Britain with the reliable, low carbon electricity the country needs. This will help postpone the energy gap in the short term, but underlines the need to move forward with plans to build the next generation of nuclear stations to provide reliable, energy for the long term.”

The news follows the seven-year extension of the firm’s two power stations at Hinkley Point B and Hunterston B to 2023. The energy supplier has plans to build four new nuclear plants, which it claims could generate enough electricity to power 40% of Britain’s homes. EDF Energy currently supplies gas and electricity to more than 5.5 million business and residential consumers.

Last week the supplier won a contract to supply Network Rail with low carbon electricity for 10 years.