Stories tagged potential energy


Ten abandoned mining pits in Minnesota's Iron Range could have new life as pumped-storage hydroelectricity plants, according to a University of Minnesota,* Great River Energy, and Minnesota Power study.

[Hey, now: did you click on the hyperlink above? I don't put hyperlinks in posts for my own amusement, you know. They're for your viewing pleasure and learning enjoyment! Seriously though, click on them for great explanations, photos, diagrams, graphs, and more. You won't be disappointed.]

Match made in Minnesota: Wind and water "play nice" in pumped-storage hydroelectric technology.
Match made in Minnesota: Wind and water "play nice" in pumped-storage hydroelectric technology.Courtesy Steve Fareham

Pumped-storage hydroelectric technology sounds like something from a science fiction movie, but it's really just a neat combination of water and wind energy technology. What makes pumped-storage hydroelectric projects sexy is that they make it possible to store excess energy generated by wind turbines on windy days. This stored energy can then be used during the inevitable calm days -- addressing one of the biggest issues for today's wind energy industry!

How does it work?

It's basic physics, my friends: building potential energy and releasing kinetic energy. Specifically, excess energy generated by wind turbines "is used to pump water from a low-lying reservoir to a higher elevation pool" within the mine pit. This builds the potential energy of the water. Then, when that energy is demanded, "water from the upper pool is released generating hydroelectricity and refilling the lower pool." This releases kinetic energy, which can be turned into electricity.

How effective is it?

Researchers estimated that a pumped-storage hydroelectric facility built in Virginia, MN could output the same electricity as a "modest-sized" generator burning natural gas. However, at a cost of $120 million, the pumped-hydro facility would be more expensive than a comparable natural gas generator.

There are 40 U.S. locations currently employing pumped-storage hydroelectricity technology, but there are no definite plans for any such projects in Minnesota -- yet.

Read the Star Tribune's coverage of this story here.

*Including scientists from UMD's Natural Resources Research Institute, St. Anthony Falls Laboratory, and Humphrey School of Public Affairs; and funded largely by the Initiative for Renewable Energy and the Environment.