In Nevada alone, the mining industry drills over 2,000 exploration holes per year. They do so to the depths needed to also verify whether the location is suitable for geothermal energy, so it makes sense for them to assess suitability not just for minerals but for geothermal, explains Ryan Horns writing for NREL. Leveraging that data, knowledge, and expertise will expand the geothermal exploration workforce, increase the rate of geothermal resource discovery, and potentially reduce geothermal’s levelised cost of energy by up to 30%. And re-assessing the more than 3 million abandoned mining wells across the U.S. is worth doing too. In fact, some of the mining operations could themselves be powered by any geothermal energy they can successfully harness, instead of running on diesel.
A partnership between the mining and geothermal industries could lead both toward a more lucrative and greener future.
Across the United States there are more than 3 million abandoned mining wells. Each hole drilled into the ground offers more than just the ghost of minerals never found. There are layers of valuable data waiting for the right audience.
National Renewable Energy Laboratory (NREL) Senior Legal and Regulatory Analyst Aaron Levine said he hopes the mining industry becomes that audience.
In his new research, “Mining G.O.L.D. (Geothermal Opportunities Leveraged Through Data): Exploring Synergies Between the Geothermal and Mining Industries,” Levine offers a two-pronged strategy of investigating mining data and taking advantage of hidden geothermal renewable energy resources.
“Our goal is really to target the mining industry for this opportunity and really make them understand the potential synergies between the two industries,” Levine said.
Geothermal data from drilling mines
Geothermal energy is a hidden asset, he said, often located one or two miles underground. It is challenging for the geothermal industry to spend millions in exploration and find nothing.
One key geothermal exploration method is temperature gradient drilling. Throughout 2017, 31 wells were drilled in Nevada at already identified geothermal fields. In comparison, the mining industry drills more than 2,000 in Nevada per year and to similar depths.
Levine said the common ground between geothermal and mining industries doesn’t end there. Additional shared exploration includes surface mapping, geophysical and geochemical analysis, remote sensing, and geologic and conceptual modelling.
NREL researchers are looking at data where mines were seeking gold or other minerals and found nothing, except perhaps evidence of geothermal energy resources. For minimal costs, the study recommends the mining industry catalogue such explorative data and potentially monetise it for geothermal uses.
Mines powered by Geothermal
While some mining companies are shifting more toward renewable energy resources, Levine said many are still reliant on diesel fuel to power operations, especially at remote mines. The study discusses the potential of utilising geothermal energy resources on-site to help achieve improved environmental performance and decarbonisation.
Existing mines on federally managed public lands with approved plans of operation may even claim a non-competitive leasing right to the geothermal resources, which may further simplify the exploration and development of geothermal resources discovered through mining data. Case studies described in the paper reveal how roughly 200 MW of net power was discovered via previous mining exploration activities.
Ultimately, leveraging mining industry data, knowledge, and expertise will expand the geothermal exploration workforce, increase the rate of geothermal resource discovery, and potentially reduce geothermal electricity’s levelised cost of energy by up to 30%. The mining industries win by leveraging geothermal energy to provide a potential electricity source to improve environmental performance and decarbonisation.
NREL is transforming energy through research, development, commercialisation, and deployment of renewable energy and energy efficiency technologies. Learn more about NREL’s geothermal research.
Ryan Horns writes for NREL