What do hundreds of abandoned metal mines and high electricity rates have in common? Well, in Michigan’s Upper Peninsula, research is underway that could adapt the contours of underground mines to harness pumped hydro storage. Surplus power would pump groundwater, which tends to flood mines when they are abandoned, up an incline. When energy demands are higher, the water would drop down the mine shafts through turbines that churn out electricity.
Michigan Technological University, with funding by the Alfred P. Sloan Foundation, is studying whether communities could transform abandoned mines into valuable energy storage. University researchers are partnering with the Marquette County city of Negaunee, population 4,500, on a pilot project that could help mining communities turn liabilities into assets.
Professors and students will investigate whether an underground pumped hydro storage facility is technologically, environmentally, and economically feasible. They will design such a facility and will translate their findings for policymakers and developers.
If all goes as planned, the goal is to develop a nationwide map of old mines that might be suitable for storing energy, said Roman Sidortsov, an associate professor of energy policy at Michigan Tech.
Public concerns with the ecological impacts of water diversions and impoundments, combined with resistance to infrastructure development by neighboring property owners, has often meant that permitting utility-scale systems is difficult. “If we move the entire system below ground and make it self-contained, there would be no effect on surface water flow, ecological systems, or landscapes and scenic views. An underground pumped hydro storage system might be essentially invisible,” Sidortsov said.
The Legacy of Free-Wielding Mining
The American West is rife with abandoned mines, a legacy of policies like the 1862 Homestead Act and 1872 Mining Law that enabled the settling of the region and triggered a seemingly lawless development of resources. Numerous companies and individuals abandoned many mines after extracting their precious minerals.
The most concerning situation created by abandoned mines is their threat to water resources, namely acid mine drainage, which is highly acidic wastewater that is toxic to fish and other aquatic species. It can also pose major threats to human health. The EPA estimates that 40% of the West’s headwater watersheds have been polluted by mining.
In the mid 1990s, a Michigan Tech team cataloged more than 2,000 shafts from 800 mines in Marquette County and seven other western UP counties.
Hundreds of thousands more mines exist across the country. Preliminary research suggests the Negaunee mine alone, where the research will focus, could store enough electricity to power Negaunee and surrounding cities for several hours.
Hydro’s Legacy & Possible Application for Energy Storage
Pumped hydro storage is a mature technology used around the world. Placing such a system below ground is what makes the new pilot study collaboration quite unusual.
A press release from MTU outlines the basics, which are the same as any hydroelectric power generator: Store water in a high-elevation pond or tank, or behind a dam, then allow the water to flow down through a turbine to generate electricity.
Pumped hydro storage, the researchers assert, is among the cleanest and most efficient way we have to store electrical energy.
Experts have long seen large-scale hydro storage as a tapped-out market in Michigan and beyond, largely because the best locations had already been used, and the projects — which can endanger fish and other wildlife, if not painstakingly addressed — are nearly impossible to permit.
Stored energy for future use is a highly valuable resource for stabilizing the electric grid. Experts see advances in the field as a key piece of goals to slash carbon dioxide emissions in the coming decades by accommodating more intermittent renewable power added to the grid.
“Battery storage cannot match pumped hydro yet in terms of scale,” Jeremy Twitchell, an energy research analyst at the Pacific Northwest National Laboratory, said at an energy storage conference hosted by Michigan agencies. But in Negaunee’s case, the storage facility would use surplus power to pump water up to a certain elevation. When demand outpaces power supply, the water runs down into turbines, which then generate electricity.
There is another potential benefit to such a hydro energy storage project, as the mines are generally already hooked up to power lines. Such power lines could require upgrades once a storage facility would be ready to go online, but that would be far less expensive than building new hookups. If it works, the researchers hope energy storage could bring more economic development to Upper Peninsula communities besieged by high power prices.
The project could offer inexpensive heating and cooling to businesses and facilities, which could attract potential employers while commemorating the region’s mining heritage. Indeed, the Upper Peninsula’s biggest electric company — Upper Peninsula Power Company, which serves 54,000 residents in 10 counties — has some of the highest rates in the country, second only to Hawaii.
The 2-year pilot project will focus on the Mather B iron mine, which closed in 1979 and whose former administrative offices are now a high school.
The Best Part is that It’s Underground — Out of Sight, Out of Mind
Unlike existing pumped hydro facilities, Michigan Tech researchers envision keeping the system completely underground, inside the former mines. That could minimize environmental impacts, ease permitting and still allow for redevelopment atop former mining sites.
Negaunee City Planner David Nelson describes the excitement behind reusing an old industrial site that no longer has any use at all and, instead, using that as energy stabilization for the entire Upper Peninsula. “It would all be contained underground, which makes the surface still reusable for development in the future.”
I reached out to David Nelson, Planning and Zoning Administrator at City of Negaunee, Michigan. Here are his comments:
The citizens of Negaunee are becoming aware of the Michigan Technological University’s pilot project “a little bit through the media and through social media. They seem very interested. Yes, there are some reservations, mostly about the water quality inside the mine, that there is a discharge inside the mine. It’s my feeling they need to be educated that there is no discharge.”
Nelson says believes that the community is getting enthusiastic about the project. “My own concerns are about the stability of the mine itself and how the researchers will be able to mitigate possible erosion.”
He added that the “city of Negaunee is very interested in partnering with Michigan Technological University, as this seem to be a very worthwhile project.”
“We do not need to come up with something revolutionary or different, because our confidence is that the existing technology will work,” Sidortsov acknowledged.
The Mather Mine is in a efficacious spot because it’s split between a flooded lower level and a dry upper level where equipment could sit and water could be stored. Many other mines offer similar contours.
The Tech researchers said they would hold community meetings throughout the project to make sure residents could offer input and have opportunities to come to understand the work being done. Learning about the Negaunee’s history and community has helped the Tech team narrow its focus to Mather mine, rather than disturbing the remnants of another mine, — the latter of which was the site of a devastating accident long ago that left miners entombed. Working with the community from the onset of the project could help developers avoid work stoppage and limit costs that might result from community resistance.
“If it goes national, given what we know about the size, it could be a game changer,” Sidortsov said.
Shout out for the original inspiration for the story to Bridge: Michigan’s Environmental Watch.
Unless otherwise noted, images copyright free via Pixabay.