Abandoned Mines Hold Potential To Capture Wind Energy

By KBJR News 1

December 20, 2011 Updated Dec 20, 2011 at 12:02 PM CDT

Duluth, MN - (Northland's NewsCenter) - Minnesota's Iron Range is pocked with ponds and abandoned open pit mines.

Spots, that researchers say...could help us use energy more efficiently in the future.

A study released by the University of Minnesota Duluth's Natural Resources Research Institute shows that water-laden pits and ponds have the potential to store wind energy by using a process developed in Europe in the late 1800's.

"We studied the potential for a big energy storage facility, using some of the abandoned mine pits on the Iron Range to enable us to basically take advantage of the intermittent nature of wind," says Director of the Center of Research and Technology Development at the Natural Resources Research Institute, Don Fosnacht.

Researchers say the ponds have the potential to more effectively use intermittent renewable energy sources, such as wind to meet state renewable energy mandates of 25 percent by 2025.

"You pump the water up when it's not being needed for other uses. And then when you do need more power, instead of having another power plant somewhere to have to turn on, you just let the water flow back through the pump generator system and it generates electricity needed at that time," Fosnacht says.

The process would use excess late-night wind energy to pump water uphill from the pits to a higher-elevation holding pond.
Minnesota Power partnered with NRRI for the research project to see if it would benefit its wind farms.

"We wanted to see, were there opportunities, we're there opportunities within our own region as far as insuring that we get the most value out of our renewable energy," says Manager of Corporate Communications at Minnesota Power, Amy Rutledge.

Researchers say when the electricity demand goes up during the day; the process will then reverse the flow and will capture the energy in hydro turbines.

"So environmentally I think it can be very well controlled and it could take advantage of resources we have up on the Iron Range beyond just the mining," Fosnacht says.

Since Minnesota Power is the largest hydro operator in the state, Rutledge says they wanted to see if there were any synergies between hydro, wind and the region.

"So the information from this study we certainly will take a closer look at that and see how can we asses that information in storing energy as that applies to out long range resource planning," Rutledge says.

Researchers say the pumped-hydro storage could have long-range implications for adopting renewable energy technologies for Minnesota.

It would cost roughly 130-million dollars to build an energy storage facility...but researchers say it would benefit energy companies in the long run.

Written for the web by Danyel Piecek.