ST. CLOUD – The sewage plant in this city does something even a non-engineer might find remarkable: It makes so much of its own energy that on some days, when the sun shines bright, the plant’s managers don’t need to buy electricity.
Instead, they sell it.
That’s despite the fact that such plants are notorious energy hogs, burning up the equivalent of a small neighborhood’s monthly electrical use every single day to move and clean city water.
In St. Cloud, though, a pair of powerful solar arrays and a state-of-the-art biodigester that turns sewage into electricity, heat and fertilizer sometimes generate more power than the plant can use. That happened for the first time on April 12 of last year. Since then, it’s happened on 30 additional days, most recently on June 5.
Mentioned: Great Plains Institute is a McKnight grantee.