Research by the the Australian Photovoltaic Institute says at least a third of the roof space in the city's centre could house solar panels, generating big savings on power bills and on greenhouse gas emissions.

The institute has produced a map of Civic showing the potential for rooftop solar, and hopes to soon chart the rest of the ACT and Australia to encourage more people to install panels on their homes and businesses.

"The CBD at the moment has about 1.2 megawatts of solar installed and we've found there's a minimum capacity for 46 megawatts of solar on the rooftops of Canberra," Australian Photovoltaic Institute chair Dr Renate Egan said.

"That would produce enough electricity for 12 per cent of the load in Canberra and save local businesses up to $14 million a year."

Dr Egan said that estimate was "conservative" and the output could be nearly doubled with a different orientation of the panels.

However she acknowledged it was not possible for many businesses to install solar as there was no benefit there for the building owner.

But she said solar was now "the cheapest new form of electricity generation" with a payback time of between five and six years.

ACT climate change minister Shane Rattenbury said because of that short payback period, the government did not need to offer incentives to businesses to install solar as it "makes economic sense without any business subsidies".

"This is a good investment. If you combine this with the battery program that the ACT government is supporting you can make a very sensible economic decision to go and put solar on the roof," Mr Rattenbury said.

Dr Matthew Stocks from the ANU Research School of Engineering said many installations were now being done on an economic basis.

"We're starting to see a change in the Australian electricity system to a system that is much more fitting to renewables purely on an economic basis, not because we want to be green and clean," Dr Stocks said.

The study also looked at how several landmark buildings in Canberra could use solar.

The researchers estimated 58 per cent of the Australian War Memorial Roof could be covered in panels, yielding up to 1682 megawatt hours a year.

About 45 per cent of the Canberra Convention Centre roof could be covered in solar panels, generating up to 1005 megawatt hours a year.

The ACT Legislative Assembly roof could have up to 64 per cent of its roof covered in solar panels, generating 360 megawatt hours a year.

However Mr Rattenbury said he investigated that option when he was Speaker, and there were heritage restrictions on the copper roof that did not allow it.

"It's probably time to take another look and see if the technology has altered in a way that the Assembly can now come on board," Mr Rattenbury said.

"There is so much roof space in this city and it is a way of the future for Canberra because there is limited land space of course so using it up with solar farms is not always the best use and we've certainly got a lot of roof space that could be utilised even though we're not currently making the best use of it."

Find the Australian Photovoltaic Institute's solar panel potential map at: pv-map.apvi.org.au/sunspot