Coal mine shafts on the brink of closure in Asturias, Spain, could be transformed into geothermal boilers to provide heating and hot water to towns nearby. Considering the 60 some-odd years of stripping the earth of coal, it’s nice to see researchers planning to use the mines for eco-friendly purposes.
Photo Credit: NIOSH
Engineer Rafael Rodriguez and colleague Maria Belarmina Diaz developed a way to estimate the amount of heat a tunnel may provide. Their goal is to make use of low-intensity geothermal energy from the internal heat of the earth.
Advantages of mine shaft boilers:
- Predictable energy production levels
- Reduction of CO2 emissions
- Not vulnerable to changes in climate, unlike solar and wind power
- Doesn’t pollute the environment
- Profitable over the long term
- Doesn’t require new development on big sites
Testing and research needs to be conducted at mines that are still in use but are on the verge of being abandoned. Once a mine is abandoned, access is cut off. However, while still active, they have easy access to the tunnels and can easily gather data about ventilation and the rock properties. They can even program the closure of some sections to use them for geothermal energy production. It’s possible to work with closed mines, but it’s not as easy to make modifications, gather data, and make improvements.
Using a two-kilometer (6,561 ft.) mine shaft, the study evaluates the temperature of the rocks 500 meters below the surface, which are 86 degrees Fahrenheit. They’re considering forcing water through tubes at 45 degrees that would return 54 degree-water for local towns to use.
As more research unfolds, you’ll know about it here.