Rupert Armstrong-Evans has been invited to give evidence to a parliamentary inquiry into generating power from the huge Bristol channel tides.
Designs for a "reef" drawn up by the North Cornwall-based engineer – which were conceived while in the bath – were backed by environmentalists the last time the Government examined energy schemes in the estuary.
The coalition Government backed away from getting involved with all the Severn energy projects, citing the huge costs to the public purse, in 2010.
But a consortium including Hafren Power, backed by former Labour minister Peter Hain, is now proposing a barrage between Cardiff and Weston-super-Mare, Somerset, with private sector money thought to be coming from the Middle East.
Mr Armstrong-Evans, who created Britain's first-ever renewable energy company in 1973, is expected to appear before the Energy and Climate Change Select Committee of MPs in Westminster on January 30.
The Cornish inventor argues his designs differ considerably from those being pushed by Hafren.
By building the "reef" between Aberthaw in the Vale of Glamorgan and Minehead in Somerset, the structure will generate more power, he says. It will also create more jobs and cause significantly less environmental damage than a conventional barrage.
His firm, Evans Engineering, based in Launceston, builds water turbines, waterwheels, pumps, pumping systems and equipment for the water industry.
In written evidence to the committee, Mr Armstrong-Evans – who is backed by Brian Mathew, a Liberal Democrat parliamentary candidate for North Somerset at the last election – says the "reef" is "our generation's opportunity to build an iconic green energy project, it would be the greatest machine on earth and visible from outer space with the naked eye".
He goes on: "It would be our generation's Hoover Dam or Great Wall of China and it would say that we care enough about future generations to invest in them rather than leave a legacy of a resource- depleted planet and a stockpile of spent nuclear waste."
He argues the scheme could be paid for by a "green bond" – meaning thousands of people could own a stake in "what is a part of our natural heritage".
Estimates have suggested there is enough power stored in the Severn – which boasts the world's second largest tidal range – to generate 5% of the UK's electricity, and construction could sustain 10,000 jobs.
