One participant, the University of Minnesota at Morris, already uses 100% renewable electricity, but is now looking for options to eliminate its natural gas heating systems.
A startup company is beginning to market geothermal systems that circulate heat from shallow aquifers.
A developer is pursuing city financing to build an aquifer thermal energy system as an alternative to natural gas.
Both new construction and retrofits can move to net-zero greenhouse gases and save money, experts report.
Geothermal advocates argue the heating and cooling systems are a good option for homes and businesses in urban and suburban areas.