Helm, who is also a professor of New College Oxford, has questioned whether UK consumers will be able to foot the bill for offshore wind energy.
He suggested gas generation could be a more affordable low carbon alternative.
Helm holds a number of UK and EU roles including special advisor to the European Commissioner for Energy and a member of the Economics Advisory Group to the UK minister for Energy & Climate Change.
Speaking at the Economist Energy Summit in London, Helm said: "There is a real doubt whether energy customers can afford the £100 billion UK offshore wind would add to their bills.
"Switching from coal generation to gas generation would only cost £10 billion and still help Britain meet its 2020 carbon emission targets"
Helm said that gas was now plentiful and that electricity generated from gas cost £60 MW/h compared with £180 MW/h.
He added: "The market should decide the best generation option, rather than government driving a crash programme of offshore wind."
However, Volker Beckers, CEO of RWE Npower, told the conference that offshore wind was a key part of Europe’s electricity generation mix.
While International Power executive director Steve Riley, said that although his company was involved with onshore wind, it currently saw offshore wind as "too risky".