You’ve heard it before: Taking full advantage of wind power is dependent on finding an economically viable way to store its production, which often comes at night, when demand is low. In Minnesota, where wind provided just shy of 10 percent of the state’s electricity in 2010 and continues to grow, a new study is suggesting that a viable way to do just that might be there for the taking in the Iron Range.
This region in the northeast part of the state is marked by hundreds of old open mining pits. The idea: Use excess wind power to pump water from lower-elevation pits to higher elevation pits. Then when energy is needed, the water can released downhill, with its energy captured by a hydro turbine. The process could be repeated ad infinitum. According to the study by the University of Minnesota Duluth’s Natural Resources Research Institute, for every 100 megawatts (MW) of power it takes to pump water up hill, 80 MW could be produced.
“The altered landscape of the Iron Range makes it ideal for this purpose,” Don Fosnacht, the study’s lead investigator, said in a statement. “There are over 100 mining pits, and those near ridges or cliffs would provide the necessary water reservoir prospects to allow the concept to be practically implemented.”
One utility rep cited by the university sounded optimistic – well, let’s call it cautiously optimistic – about the prospects.
“Minnesota Power will continue to assess energy storage development and the role pumped hydro might play in its long-range plans to best serve our customers,” said Al Rudeck, vice president of strategy and planning for Minnesota Power. “This study provides a good basis for that continued assessment.”