Most underground mines involve ventilation systems. You need to push cool surface air down into those hot, deep workings to keep them cool. The right temperature in underground mine workings is not only a matter of pleasant surroundings. I recall reading that the accident rate jumps as the temperature increases: at about seventy degrees things are optimally safe, at eighty degrees the accident rate soars. Ventilation systems are needed because the rocks are hot from the heat generated by radioactive processes deep in the earth’s interior. Now professors from the University of British Columbia (UBC) are looking at tapping into the heat from closed underground mines. They reckon this is a cheap source of energy for those dwellings and businesses that remain behind after the mine is shut down. Now that is sustainable development for you: first a mine and then a solarium, or should we call it a heatarium or mine-arium?
To be serious, at this link is a CBC interview with Dr. Mory Ghomshei of UBC. It is light fair, but fun as he peers into a rosy future of energy from abandoned mine shafts in cold parts of the world. I can think of all sorts of engineering and environmental factors that are going to have to be addressed before we can cost-effectively tap into natural radiactively generated heat from old mines. Not the least is the nasty tendency the groundwater has of rising to pre-mine levels and flooding old workings. Then there is the issue of keeping the headgear and shaft open for continued access to keep the heat exchange equipment functional.
The more I think about it, the more I wonder if this is feasible except in the most isolated instances. This cynical thought is not dissipated by Ghomshei’s statement:
“It is going to be relatively expensive, but Iunderstand the energy cost of Yellowknife exceeds $100 million per year. So if you can spend a few tens of millions of dollars to tap into a great resource—that would be absolutely rewarding and would be paid back very shortly. It is renewable energy because of the mine workings which is quite extensive, so the natural gradient of the heat into the mine workings would replenished the heat and the water would be replenished by the groundwater. So it is a 100 percent renewable resources.”
That is if the water that comes out is not acidic, which in most mines in the north of Canada is probably the case. The thing I find so disconcerting about Dr. G’s interview is that ever present falling back on the need for the federal government to pay the bill. If his idea is such a good one, why not get a commercial enterprise going about it? Why this constant: I have a good idea, now let us get the taxpayer to fund it. What is wrong with free enterprise? After all this is not research: this would be a good old power production system. It’s all very well, and is indeed the job of professors, to dream up the future. But they should show some respect for the taxpayer in demanding my money (albeit yielded to the government) to put into place their dreams.