The Department for Energy and Climate Change says it has "needed to drive through reforms to secure investment in new generation to keep the lights on in the years and decades ahead" after suggestions it may have cost consumers by awarding eight renewables contracts too early.
A spokesperson said the National Audit Office's report recognises that the early deals were "designed to offer better value to bill-payers" by reassuring investors.
"Without that investment, projects would have been unable to go ahead or been significantly delayed - putting our future energy security at risk."
More top news
The EgyptAir plane that crashed into the Mediterranean Sea did not swerve before disappearing off radar, according to Egyptian authorities.
Jose Mourinho is a step closer to being appointed the new Manchester United manager after Louis Van Gaal's turbulent reign was ended.
Greek authorities began to clear the country's largest informal refugee camp on Tuesday - blocking access to the area in the process.