The Committee on Climate Change’s report into future energy needs recommends construction of at least another two nuclear plants above the current building plans.
The committee believes nuclear power will remain the cheapest way for the UK to grow its low-carbon energy supply for at least a decade.
The news is a much-needed boost to a sector still reeling from the Fukushima disaster in Japan which reignited opposition to nuclear power.
The committee said renewables should provide 30-45% of the nation’s energy by 2030.
But ambitious plans for offshore power are currently too costly according to the committee which was asked to advise on the energy mix shortly after the coalition came to power.
CCC chief executive David Kennedy said: “People argue that offshore wind is very expensive – and it’s true, it is more expensive at the moment than some other technologies, so nuclear at the moment looks like the lowest cost low-carbon option.
“But we can expect significant cost reductions over the next two decades across a range of technologies, whether wind, marine or solar, and that’s why these technologies are promising.”
Wind could replace nuclear as the cheapest option within about 15-20 years, he indicated.
Ambitious greenhouse gas targets mean that by 2030 virtually all electricity would need to be generated through low-carbon technologies like nuclear and renewables.
This would require an additional two or three nuclear reactors on top of those developers are already planning to build.
Energy giant and nuclear reactor builder EDF said: “The CCC has said that safe nuclear power, the lowest cost, large scale, low-carbon electricity source, is a key element; we agree.
“EDF Energy has already taken steps to respond to early lessons from Fukushima.
“The designs we propose for the future already build in the lessons from previous extreme events, inside and outside our industry and we will take account of new lessons from Japan.”