Isle of Wight Council bosses have overturned a vote by councillors - who had rejected the partnership to secure £900 million of funding.
Prince Charles Opens Bio-Gas Plant
The Prince of Wales has opened the country's first commercial full-scale anaerobic digester and biomethane plant, situated in Dorset.
Charles praised the ''remarkable engineering feat'' which has made the plant the first in the UK to inject renewable gas directly into the local distribution network on a permanent basis.
The plant will provide renewable gas directly to the Poundbury - the experimental new development built on the outskirts of Dorchester on land owned by the Duchy of Cornwall. It is based at nearby Rainbarrow Farm and could supply up to 56,000 new-build homes in the summer with renewable gas.
The Prince, who takes a keen interest in renewable energy, has been consulted at every stage of the project, which is owned and run by JV Energen - a joint venture between local farmers and the Duchy of Cornwall.
Charles was taken on a tour of the plant, met the people behind the project and also unveiled a plaque to mark the occasion.
Addressing guests, he said: ''As far as I am concerned it is a very exciting and encouraging day.
''I have been badgering the Duchy and others over the years to find a way of kick-starting the anaerobic digestion sector in this country.
''As we have quite a lot of people here from the Continent, you may well realise that in the Netherlands and Germany they are much further ahead on this front.
''I am particularly pleased and proud that we have been able today to launch this remarkable engineering feat of the first gas-to-grid operation.''
Earlier in the day, Charles met patients as he opened a new cancer unit at Dorset County Hospital in Dorchester. During the visit, which lasted an hour and a half, the Prince also toured the digital mammography suite and met orthopaedic patients.
The busy road's being made two lanes in both directions between Segensworth and Titchfield - it's due to take 18 months.
Police want to trace man after 11-Year-Old Approached Near Oasis Academy
Family Appeal Is Shared Online After 14-Year-Old Missing Since Friday
Recently Played Tracks
Deposit £10 to get a £40 Welcome Bonus - That's £50 to play bingo, slots and more!*
Over 50 tracks to make you feel-good. New album out now...
Find your local four day weather report here.
What's happening on the roads where you are?
Make Heart the soundtrack to your day and you could be a winner with great prizes up for grabs throughout the day.
Find out more about some of the companies advertising on Heart.
Get some great ideas on how to advertise your business on radio, online and on mobile.