BOISE, Idaho — The city of Boise is looking to expand its geothermal heating system by 40% as part of a goal to become carbon neutral by 2050.
The city pumps 250 million gallons of 177-degree geothermal water to 96 buildings through 21 miles of pipes. City officials tell The Idaho Statesman that's about 2% of the city's energy resources. The city says the heated water comes from a river of geothermally heated water flowing under the nearby foothills.
The water is heated by the Idaho Batholith, a massive igneous intrusion of granite producing heat through decay of isotopes like uranium, thorium, and potassium.