May 26, 2012 at 8:30 am in Grand Forks Herald
Brainerd officials are looking at an unconventional place for a future energy source: the sewers.
Brainerd-based Hidden Fuels began working with the city and the school district in 2009 and later installed sensors in the sewers. For more than a year they measured the temperature and the amount of sewage running through them. Continue Reading