He said an ambitious scheme - which could be extended across Europe - would replace the "old fashioned and inefficient grid" with infrastructure stretching from Scotland to the south of England and across to the Dogger Bank. He said the project could open up increased opportunities for offshore wind, marine and tidal energy.
Speaking at the British Wind Energy Association annual conference he said the new grid would also increase the demand for wind turbines in UK docks, creating jobs in deprived parts of cities such as Hull and Newcastle.
He said: "These are ambitious plans, I don't deny it. But ambition is precisely what we need.
"The new grid would meet future demands in a way that is more efficient, more reliable, less harmful and ultimately cheaper.
"It would also increase the demand for wind turbines built in UK docks, creating jobs in some of the UK's most deprived communities such as parts of Hull and Newcastle."
Mr Clegg outlined his plans for a supergrid as part of measures to boost renewable energy and green jobs and develop a post-fossil fuel economy in Britain.
His call for a massive expansion in renewable energy comes the day after the Government announced the UK had overtaken Denmark to become the world's biggest producer of offshore wind.