A trifecta of solar advocates is targeting Nevada’s closed mines for new solar projects or other renewables to help the state meet its new 50% renewable energy portfolio standard by 2030. The Rocky Mountain Institute, the Nature Conservancy, and the Nevada Mining Association are cooperating both to get solar projects developed on the mine sites and to encourage new legislation that will facilitate the brown field development.
“We did a high level analysis of Nevada and came up with almost 3 million acres of closed mine sites; you can put a ton of solar, wind or geothermal on that,” says Paolo Natali, the director of Rocky Mountain Institute’s Sunshine for Mines program.
Several mining companies in Nevada are in discussions with RMI about project feasibility, but the first project to be constructed may be in Arizona, where discussions have advanced with BHP Billiton, the Anglo-Australian mining company headquartered in Melbourne, Australia, Natali says.
The BHP project, ongoing since 2017, includes a sustainability analysis of BHP’s North American portfolio of 22 legacy mines to identify a ranking of the best potential sites for redevelopment into grid-scale renewable energy generating assets, RMI reports. “As a result, the team identified over 500 MW of potential new capacity build. Sunshine for Mines’ analysis considered both commercially established technologies like solar PV, wind energy, pumped hydro, and lithium-ion battery storage, as well as innovative options including electricity generation from shaft airflow and flywheel batteries,” the project summary says.
“Post-production mine sites — brownfields — are still connected to the grid, and the tailings piles often are flat and have slowly descending inclines, which would be perfect for solar panels,” Natali says. “The communities where mines have closed also are interested in new economic development, so there is no opposition to solar,” he says.
Solar PV is rapidly becoming more cost-effective, both for remote off-grid mines operating diesel generators and for many grid-tied mines, the Sunshine for Mines profile notes. Installing solar at mines reduces carbon emissions at the gigaton scale and demonstrates sustainable mining practices, it adds. However, risks associated with brownfields make solar projects more expensive than on greenfields, points out Natali. “That’s why we need legislation to make brownfield site development less risky and more attractive,” he says.
RMI partnered with the Nature Conservancy this past summer to target Nevada mine sites in particular. The Nature Conservancy similarly partnered with the Nevada Mining Association earlier this year to promote new legislation that would foster more solar and other renewables on closed sites.
Thus far, the legislative effort has resulted in one regulatory change in the mining code in Nevada, which now specifies that renewable energy and energy storage are appropriate uses of mining sites, says John Zablocki, the director of the Nevada office of Nature Conservancy.
“The concept of adding solar to mine sites is very well supported in the state. We hope that the incoming administration will make this a policy priority,” says Zablocki. “We have not encountered any opposition, and environmental groups like mine are in favor of it. It’s truly a win-win situation,” he says.
“A year ago, we had the University of Virginia do a study on the barriers to renewable energy development on brownfields or other degraded sites, and mining sites was one of the best candidates for the development; there is huge potential,” says Zablocki. “The Environmental Protection Agency has identified millions of acres of land that meet technical criteria for renewables development, but to make these commercially viable sites, we need policy tweaks,” he says.
Sunshine for Mines, which is global in its scope, has recently helped Johannesburg-based Gold Fields complete a pre-feasibility study for a 40 megawatt solar project at its South Deep mine site in the West Rand, in South Africa, says Natali.
RMI’s global Renewable Resources at Mines tracker provides sourced data on renewable energy projects sited at mines, either active or legacy, as well as projects owned by mining companies. All data collected is publicly available and includes both commissioned and announced projects, RMI reports.
The summary stats for the most current Renewable Resources at Mines assessment are:
- Number of Sites: 57
- Countries: 21
- Companies: 47
- Total Capacity: 2007 MW
- Total Installed: 1178.2 MW
- Total Announced: 713.9 MW
- Average System Size: 35.2 MW
- Median System Size: 5.0 MW
- Wind Sites: 43
- Solar Sites: 16
- Commissioned Sites: 41
- Sites with Storage: 5