Expansion eyed for geothermal heating network in Boise, Idaho

Capitol Building, Boise/ Idaho (source: flickr/ TravelUSA, creative commons)

The City of Boise in Idaho is planning to expand its geothermal heating system by 40% with the ultimate goal of attaining carbon-neutral heating by 2050.

The city currently pumps 946 liters of geothermal waster with a temperature of 80 degrees Celsius through 34 kilometers of pipes. The plan is to increase geothermal water usage by 18.9 million liters per year until reaching 1.6 billion liters. This can be done just by expanding the network – no new production wells are planned.

There are four geothermal networks in Boise, a city which has been using geothermal heat for about 130 years. “It’s kind of one of those hometown assets that (Boiseans are) really proud of,” commented Climate Action Manager Steve Hubble.

The inferred heat source of the geothermal water in Boise is the Idaho Batholith, a massive igneous intrusion located under the nearby foothills. A large fault line runs through the Boise foothills, serving as the channel for the geothermal water to come close to the surface. City-owned wells in the foothills extract the hot water, which is them pumped to the heat network before being returned to the aquifer.

Source: AP News