The idea is one of 20 radical solutions to the threat of global warming to be proposed during presentations at a conference in Manchester this weekend

The British public could invest their savings in the UK’s renewable energy revolution and reap the financial rewards of helping to save the planet, under ambitious plans to be discussed this weekend.

The Public Interest Research Centre, a thinktank based in Wales, says the government could sell “energy bonds” to pay for the required investment. The scheme would be similar to war bonds, which galvanised financial support in Britain during the second world war.

The idea is one of 20 radical solutions to the threat of global warming to be proposed during presentations this weekend in Manchester. The event, organised by the Guardian and the Manchester International festival, will publish a report on the ideas, which will be distributed ahead of key UN talks on a new climate treaty in Copenhagen in December.

Tim Helweg-Larsen, director of the Public Interest Research Centre, said: “To finance renewable energy on the scale required, Britain is going to need hundreds of billions of pounds. Energy bonds are a way to unlock large amounts of money from individuals and institutional investors.”

He added: “Make no mistake, this is an incredibly expensive project, but it also has very good rates of return on investments. We should be creating the opportunity for the people of Britain to invest in their own future and a secure climate.”

People and companies would buy the bonds over the internet or at Post Offices, he said, investing anything from £10 to millions. The money raised would be dedicated to investment in offshore wind turbines and other clean energy projects. Fixed returns, backed by the government, could be paid at regular intervals, or after a decade or so when the fund matured. The increase in money paid back would be linked to the likely increase in electricity prices.

The large amounts of public investment raised by such a scheme could provoke awkward questions about how it would be allocated in Britain’s liberalised electricity market, where infrastructure such as wind turbines are largely built and operated by power companies. Helweg-Larsen said nationalisation would not be needed. An investment corporation could be set up to spend the money, either by building generation capacity directly, or by subcontracting the work to existing operators. War bonds worked in a similar way he said, with the money from the public used to pay private firms to make weapons and munitions.

Other climate-saving ideas to be discussed at the Manchester event include practical suggestions, such as alternative fuels from algae to hydrogen, as well as ways to convert the greenhouse gas carbon dioxide to methanol. Others will discuss more controversial ideas such as tighter controls on global population and rethinking conventional models of economic growth.

Stephen Salter, an engineer at Edinburgh University, who was responsible for the “Salter’s Duck” wave energy device, will present his latest idea: a form of geoengineering that uses ships to seed clouds over the ocean, designed to block sunlight.

The ideas will be judged by a panel of experts led by Lord Tom Bingham, former lord chief justice, and including Dan Reicher, director of climate change and energy at Google.org, and author Chris Goodall.