Dam Minneapolis

The Star Tribune covered prospects of adding a new hydroelectric dam to St. Anthony Falls in Minneapolis. There is some concern that it will damage the mill ruins. I was curious about a few oddities with this proposed project.

It will apparently generate enough electricity to power 2000 homes, but will only run at off peak hours.

Crown Hydro spokesman Rob Brown said water would drop through thick, durable steel pipes and wouldn't harm the mill ruins. The company would negotiate the amount of water it would leave flowing over the falls and regulate it with a computerized device, he added. Crown Hydro would run mostly at night and other non-tourist hours, Brown said. And he assured people there wouldn't be vibrations.

Evidently, the existing Xcel dam has significant periods of lessened generation due to low river levels.

Xcel's plant, which has five turbines, ran at partial capacity 22 percent of the time from the most recent time frame available, 1992 to 1997, because of low river flows, officials at Xcel said.

The idea of putting in a new facility that may negatively impact the ruins to supply a little bit of non-peak energy, assuming river levels are consistently high enough for both dams, seems suspect. That being said, I suppose it will tend to offset coal baseload so there is an upside.