I can understand why some people are sceptical; even in this relatively mild winter, it's hard to believe as we trudge about the streets that there's a ready supply of warmth under our feet.
But the study under way at Caledonian University will be looking at the disused tunnels and mineworks under the city's streets, which stay warm throughout the year and which could be tapped for cheap energy.
Glasgow wouldn't be the first city to use geothermal energy this way, but it would be a unique example in Scotland, and the benefits could be huge for a city where around a third of households live in fuel poverty.
That statistic is only likely to get worse as energy prices rise, unless we can do two things; cut down our costly waste of energy, and develop new sources of green energy.
Achieving those vital goals, reducing greenhouse gas emissions and using energy more efficiently, will require a real transformation of our energy system.
But it must be done in a way which creates a social benefit too. I think that means more than just changing the technology. We have the chance to change the ownership structure too.
We're almost all completely dependent on a few multinational energy companies, and they will always put profit ahead of public interest.
The global factors driving up energy prices can't be wished away, and it's not all the fault of these firms, but their primary function is to make bigger profits for shareholders, not to serve their customers' best interests.
Right now we're in danger of missing the chance to change that.
There will always be an important role for the private sector, but we don't need to leave these few huge firms so utterly dominant.
Some European countries have successful publicly owned energy firms too, putting the profits from the industry back into serving the public good.
Some of them are developing renewable energy in Scotland. While I welcome the investment I can't understand why we shouldn't take the same approach ourselves, and reap the rewards for the public purse.
Creating a Scottish public energy company would be a tremendous legacy for generations.
We could start building it now, if local authorities used their borrowing power to invest in profitable sources of green energy.
Different technology would work in different places, and in Glasgow underground heat pumps could be a great way to start. Elsewhere wind, solar and hydro power could be options.
Income generated could be invested in public services, or in the housing stock to cut down on energy waste and save more money.
Ultimately, if Scotland votes for independence, we'd have the chance to put a national energy company in place.
There's a real chance we could make green energy the people's energy. I don't think it's a chance we can afford to miss.