The coal mines of Springhill, Nova Scotia were huge, some of the deepest and most extensive in the world. Thousands of tunnels a mile underground delivered high quality coal until the Springfield disaster of 1958, a manmade earthquake that killed 74 miners. Then it was closed, and the mines filled with water.
Now, Springhill might once again be a major producer of energy, as engineers consider turning that water into a major source of geothermal energy. There are advantages in taking it out of the mine; one engineer said a few years back:
The Verschuren Centre for Sustainability in Energy and the Environment at Cape Breton University is doing studies about expanding the extraction of energy “in hopes of better understanding the geothermal resource potential within the former Springhill mines.”
The main advantage of a mine over a normal geothermal system is that there’s a lot of water in the mines. In a normal system you have to drill 20 or 30 wells to get the flow you need. With this system it’s possible to generate a lot of heat with just one well.
The water isn’t volcanic-geothermal temperature, it’s pretty low grade at 26° C (78° F). However that’s warm enough to heat nearby buildings now and there are technologies that can extract it (like water-source heat pumps) or devices like the Electra-therm Green Machine. This creates a dilemma for me; I have gone on for years about the difference between geothermal systems and ground source heat pumps, but this is sort of a hybrid of the two. I am not sure which camp it falls into. Or maybe I have just been wrong and have to rethink it.
It is still the kind of stuff that warms our TreeHugger hearts. A seriously depressed former coal mining community using modern technology to tap a new form of energy from the old coal mines. As the head of the Cumberland Energy Authority says in the local newspaper:
Should we move this project forward, our objectives are to create economic development which will in turn keep our young adults working in our own County and communities. This will help to reverse the economic declines, retain our own talent to keep families intact, and help improve our population demographics.
I wonder how many other abandoned holes in the ground could try the same thing. And I do wonder, do I call this a geothermal system, a water source heat pump system, or are they really a lot more alike than I thought?
And a hat tip to a tweet:
Canada: Study of Geothermal Energy from Abandoned Mines in Nova Scotia http://t.co/9ZJEGs3xpH— Geothermal Resources (@GRC2001) August 5, 2015