A Belgium firm says there is enough geothermal heat at Yellowknife's Con Mine to heat parts of the city's downtown.

The geothermal energy plan has had its critics who've said the city based the project on a temperature reading that was taken 22 years ago.

But now, Vito Engineering has done new research and says there is 1.7 megawatts of energy which could be used to heat city buildings.

Yellowknife city councillor Mark Heyck said there's also something new that came out of Vito's report.

"Because we would only be heating for eight or nine months of the year, you could use those remaining summer months to actually recharge the underground workings. It would basically become an energy storage battery that would be charged over the summer," Heyck said.

"There's various methods of doing that; could be using waste heat from some location, or solar thermal collectors that charge the underground which actually expands the size of the resource available to us when we need it in the winter time."

Heyck said confirming the temperatures in the defunct mine is only one step in the process.

"But certainly talking to the end use customers, those building owners in the downtown core who would ultimately use the energy. That’s going to be a big milestone for us once we bring those folks on side," he said.

The city also still hopes to secure federal funding for the project.