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SOMBA K'E/YELLOWKNIFE
The city received a boost in its effort to exploit Con Mine for geothermal energy when consultants from a Belgian energy company announced the location has a sustainable resource of 1.7 megawatts that could be used for future heating purposes.

City energy co-ordinator Mark Henry stands on the Con Mine site where geothermal energy would originate. - NNSL file photo

"The 1.7 megawatts at 150 cubic metres is roughly equivalent to one-half of what is expected to be needed for the district heating project," Mayor Gord Van Tighem said. "The other half would come from biomass."

The report also validates the heat of the mine at around 30 C, which the energy company - Vito Vision on Technology - calls an "average temperature." This assessment is based on "the actual water temperature that has been collected regularly over time as the water rises," said Van Tighem.

Two consultants from Vito Vision on Technology - Helga Ferket and Ben Laenen - visited Yellowknife on April 19 to present their findings from research conducted last October. Members of city administration, councillors David Wind, Cory Vanthuyne, Amanda Mallon and Mark Heyck and Van Tighem were present. A number of other guests were also in attendance. The media were not invited, but a copy of the PowerPoint presentation was later made available to Yellowknifer.

When contacted for a summary of the presentation, Laenen, the regional manager for geothermal power at Vito, said the city asked him not to talk to the media.

"They asked us that in case we were contacted by the media that we would direct you to them and (energy co-ordinator) Mark Henry would be willing to answer your questions," said Laenen.

The report, called Evaluation of Con Mine Energy Resource, looks at the history of flooding in the mine and states that water is coming in from the sides of the mine as well as its top.

Laenen went on to say he was in Yellowknife last October, which was used as an opportunity to get in touch with local experts of the mine, followed by a return visit in November to get additional data from local mine experts.

According to several people present on April 19, the meeting featured a computer interactive model to show that flooding is coming in at the top and sides of Con Mine naturally. The study also found that because doors that existed between mine stopes had been left open, more cool water will be able to flow through against hot rocks between the injector well, which brings cold water into the mine, to a production well, where heated water would be drawn back out.

"What it turns out is that the mine itself is a very good heat exchanger," said Laenen. "In that respect it is doing better than the mine we developed in the Netherlands because (Con) is a deep mine that goes down two kilometres, it extends over a wide depth range."

There is also a possibility of using solar panels to supplement the heating system.

"In the months when we are not in our heating season, we could use solar thermal or some other heating source where you could charge the underground workings where they would become an energy storage battery, essentially," said Heyck, who compared it to other areas like Drake's Landing in Okotoks, Alta., which has a system where solar panel energy is piped into the ground in the summer to heat 50 homes in the winter.

Laenen declined to say how much the company charged for the study and Van Tighem stated in an e-mail that he hadn't asked administration for the costs yet. However, the mayor did confirm the company was hired through a request for proposal process.

The city remains in negotiations with Vancouver-based Corix Utilities to create a district energy system to provide energy to 39 downtown buildings with assistance from a wood pellet boiler.

Vito's report on the geothermal potential is helpful, Vanthuyne said.

"Now there is no question, there is a geothermal source there," he said. "That had not been clear before because a number of sources had been indicating different aspects and that it was five degrees to 50 degrees (Celsius), depending on what report you looked at."

Van Tighem said this latest research broadens the potential uses for the mine in the future.

"If the district energy system gets too complex or if there is no partner or if there is a problem with marketing, it would be important to look at what else you could do with (the geothermal heat)," he said.

Heyck said the next step in the project would be taking the information gathered from Vito's study and applying it to the business model analysis the city did in 2010.

The city also awaits word on a $14-million federal clean energy funding grant, which it applied for in September 2009.

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