EDF Energy is to pay out £6 million for breaching UK energy market reporting rules regarding how much energy could be supplied by its power plants, following an investigation by the energy regulator.

Ofgem said monitoring of the French energy giant found that its thermal generation units “regularly sent misleading signals to the National Grid electricity system operator (ESO) about the capabilities of its generation plant” from September 2017 to March 2020.

The watchdog added that EDF regularly inflated the minimum amount of power it said its West Burton B plan could supply at times it did not plan to generate electricity.

Ofgem said that in “many cases” the National Grid “had to purchase more energy from the plant than needed” as a result.

These actions meant that EDF breached its electricity generation licence obligations.

EDF admitted to an “inadvertent breach” of regulations and agreed to pay £6 million into Ofgem’s voluntary redress fund.

Ofgem said that the supplier fully co-operated with it throughout the review process.

Although the breach was inadvertent, and EDF ETG considered its approach would reduce costs for the electricity system operator, we should have done better

Cathryn Scott at Ofgem said: “This case further demonstrates Ofgem’s commitment to monitoring wholesale energy markets in Great Britain and ensuring their integrity on behalf of consumers.

“Ofgem’s enforcement action sends a strong signal to all energy market participants that they must submit accurate data to the ESO.

“If they don’t, we have the powers to intervene and we are ready to use them.”

An EDF spokeswoman said: “EDF Energy Thermal Generation (ETG) takes this issue extremely seriously and apologises for the error.

“Although the breach was inadvertent, and EDF ETG considered its approach would reduce costs for the electricity system operator, we should have done better.

“We have taken swift action to prevent any reoccurrence.

“We have changed our approach and ensured it is fully aligned with the clarification in Ofgem’s latest guidance and put in place new governance arrangements to ensure ongoing compliance.”