Public tours are being run at a 30-acre solar farm in Oxfordshire ahead of shares being offered for sale.
The event at Westmill Farm near Watchfield is being organised by Westmill Sustainable Energy Trust.
The charity said the share offer will be the first opportunity for the public in the UK to buy into and own part of a large-scale solar farm.
The community-owned business will generate enough electricity to power 1,000 households.
It is hoped that people living near the farm, which is in the Vale of the White Horse near the Wiltshire border, will be persuaded to buy shares and the business will then be run as a co-operative.
Farmer and landowner Adam Twine, who set up a co-operative wind farm on the same property in 2008, said he expected to raise £4m by selling off shares, and thought the offer would be "oversubscribed".
"We will be giving preference to local people and businesses as we hope that the ownership of renewable power station will stay largely within the area," he said.
His Westmill Wind Farm Co-operative has 2,500 members, half of whom live within 15 miles of the wind farm.
The solar farm has been running since August, when £14m worth of photovoltaic panels were put in place.
The tour will begin at 14:00 GMT, with a tour of the solar farm and adjoining wind farm and will then progress to Watchfield village hall for a meeting and film at 15:30.