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Doubts linger after Vito report
Con Mine geothermal project 'dead on arrival,' mine expert says

Simon Whitehouse
Northern News Services
Published Friday, May 4, 2012

Despite the excitement at city hall last week after a presentation by Belgian scientists about geothermal heat at Con Mine, doubts remain about the viability of the project.

NNSL photo/graphic

The city has been trying to get a district energy system in place to heat 39 downtown buildings since 2007 when the possibility of using geothermal energy from the defunct Con Mine first came into discussion. - NNSL file photo

Energy usage for NWT

- 1.7 mega-watts refers to the power of the energy system. To get the total energy output, multiply this figure by the total number of hours in a year the system is in use - i.e. 5,840 hours. Hence the total energy output is 9,928 mgw/hr or 35,741 gigajoules, a measurement used for energy use.

- According to Natural Resources Canada, one gigajoule of energy could "keep a 60-watt lightbulb continuously lit for six months." One gigajoule of energy will cook 2,500 hamburgers.

- According to GNWT Environment and Natural Resources department, the average per capita amount of energy used in the NWT is 428 GJ each year. The national per-capita average is 227 GJ.

Source: GNWT/Environment and Natural Resources

Giant Mine manager Mike Borden was one of several mine experts consulted for a $115,000 federally funded, six-month study conducted by Vito Vision on Technology, of Belgium.

After attending a meeting with the company's representatives April 19 at city hall, Borden said this week he was surprised at the optimism later expressed by the mayor and councillors.

"It was interesting because I came away with the impression that the project is DOA - dead on arrival - and that is from all aspects of it," he said. "The mayor came out with a glowing statement last week, but I went back to all the mine experts (involved) and we all had the same understanding coming out that this project would be dead on arrival."

Also at the April 19 meeting were geologist and former Con superintendent of technical services Bob Hauser, Con engineer George Friesen, mine geologist Scott Cairns and Con Mine environmental superintendent Ron Connell. They had all had been consulted by the company on their understanding of the mine workings and its layout, geology, engineering and environmental information. As a result of their information and additional research, Vito made a standard computer model of the mine workings that was presented to the city last month.

City hall subsequently issued a news release which stated that the water from the mine would have temperatures between 25 C and 30 C and provide 1.7 megawatts of energy to downtown buildings.

Connell downplayed his role at the meeting, saying he was more an observer than a consultant. But he also said he was not hopeful about the project going forward.

"The general gist of what they were saying at the meeting didn't sound very positive," said Connell. "Recovering geothermal heat from the mine and economically recovering enough heat to make it useful - it didn't sound good to me."

Yellowknifer attempted to contact Hauser, Friesen and Cairns. Hauser stated in an e-mail reply he wanted to study Vito's full report before commenting. Cairns directed all questions to a media spokesperson with Aboriginal Affairs and Northern Development, his present employer, and Friesen could not be reached.

Borden pointed out that at the time of the $49-million borrowing referendum last year, the city projected a potential heat water source of over 50 C at the bottom of Robertson Shaft. This figure originally came from Dr. Mory Ghomshei of the University of British Columbia who, in 2007, presented a preliminary report on geothermal potential to the city. Borden said Vito's report last month produced figures of 25 C to 30 C.

Borden said Ghomshei also reported that there is a heat sink of water at the bottom of the mine - or an amount of space in the mine where it is extremely hot and allows for heat transfer. This point is false, he says, as the space that would allow for heat transfer is located in the upper parts of the mine, where it is colder.

Additionally, Borden points out that Vito's conclusion that the geothermal potential could provide a total output of about 36,000 gigajoules (GJ) in a year is much lower than predicted in past studies. In Ghomshei's 2007 study, it was "estimated that the renewable portion of the mine's heat can be as much as 650,000 GJ per year which is equivalent to 20 mega-watts." In subsequent studies, that figure has come down, as seen in another report by Ghomshei in 2009 (putting the estimate at 150,000 GJ). The same year, a report by SAIC Canada estimated 80,000 GJ in a year.

"If you put all those three factors together, it substantially reduces the geothermal resources to the point that the standard model wasn't even going to be put in the business model. It was that bad."

Borden said that because of the costs associated with temperature measurement, once a business model is put together, he predicts the project won't hold up. Whether there is a resource isn't really the question, he added, but whether the project is economical. He said he helped Vito attempt to get a measurement from the mine through diamond drill holes at both Giant and Con mines, as the same rock lies below both sites.

"We did get into some of the costs to get some details on temperature measurement and they were shocking," he said. "If you build that kind of reality into the business model, you will see the economical side fall right out."

For Coun. David Wind, one of the councillors who attended the Vito presentation, the issue comes down to the business case.

"My feeling is that we shouldn't get hung up on this consultant's assessment of the available heat source in the Con Mine," said Wind. "The real question that needs to be answered is whether a private entity is willing to invest in mining that heat and subsequently delivering it to customers to the city in a way that would justify the amount of money that they are going to have to invest. Will they be able to generate sufficient return for the delivery for that heat to pay for that investment?"

Van Tighem confirmed that Corix, the British Columbia company considering the merits of building a district energy system in downtown Yellowknife, has been informed of the Vito report and that city hall staff remains in negotiations with them on a final deal.

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