Are Hot Springs ​the Future of ​Farming?

Published on by in Non Profit

Are Hot Springs ​the Future of ​Farming?

A small Colorado town is using its hot springs for an unusual purpose: growing food year-round. And with geothermal energy in abundance, this could be a model used across the US. 

Their work is part of a five-year effort by the Geothermal Greenhouse Partnership (GGP) in Pagosa Springs, Colorado. The volunteer-run nonprofit, in coordination with the south-west Colorado town, is transforming the world's largest and deepest geothermal hot spring into something much more than just a travel destination: it’s using the renewable energy source to grow food year-round for the community.

Pagosa Springs is well-known in the western United States for its unique approach to geothermal energy, which is energy harnessed from the Earth’s heat. Geothermal food growing, though, is a new enterprise.

In the centre of the small downtown, on the banks of the San Juan River, sit three conspicuous, geodesic greenhouses, each 42ft (13m) in diameter. They stand in stark contrast to the old-timey buildings on the road above. All will house gardens, but each has a different mission. 

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The project’s three greenhouses use geothermal energy to help grow plants even in Colorado’s cold-weather months (Credit: Daliah Singer)

The first, the Education dome, was built in 2016. It is the only one of the trio that’s currently operational. Volunteers stop by to prune and plant every day; more than 300 students have visited the site to learn about the plants and to practice their maths or science skills; and the public is welcome from 11:00 to 14:00 on Tuesdays and Saturdays.

“Everything we do is [focused on] teaching sustainable agriculture to the next generation and growing food year-round – which is pretty special” at an altitude of 7,150 feet (2,180m), says Sally High, a former environmental educator and GGP board treasurer.

The geothermal water comes from town wells via a lease agreement with Pagosa Springs. A heat exchanger inside each greenhouse uses the geothermal liquid to heat domestic water, which is piped through the floor of the greenhouse in cold-weather months. The geothermal fluid then resumes its natural path. 

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Inside of the Education dome, volunteers prune and plant every day (Credit: Daliah Singer)

The closed-loop system is as close to non-consumptive as possible – meaning almost no water is consumed during the process, with most of it returning to the ground – and allows the greenhouse to maintain a consistent temperature that ranges from 58F (around 14C) on the coldest winter nights to 90F (32C) on a sweltering summer day. (A pond, fans, misting system, and windows also help regulate the temperature.) That means the squash, kale and beets can grow in any month – a major benefit in a high-elevation mountain town where the average frost-free growing season spans less than 80 days.

Our geothermal resource is underused and undervalued – Sally High

The Ute Indians first discovered the area’s therapeutic waters in the 1800s. More than a century later, in 1982, the town, with help from the US Department of Energy (DOE), launched a geothermal heating system that uses the geothermal water to provide heat to about 60 local businesses and residences and melt snow on the sidewalks in the small downtown. (There are around 20 such systems in the country, including in Boise, Idaho, and San Bernardino, California.)

“It’s a 24/7/365 power source; it’s not intermittent, like solar or wind,” High says. “This direct-use project… it’s absolutely replicable.”   

Pagosa Springs isn’t alone in growing food geothermally. But the process is still rare in the US. In its most recent look at geothermal direct-use installations in the country, which dated to February 2017, the National Renewable Energy Laboratory (NREL) counted just 29 greenhouses.

“One thing that’s unique about geothermal is, in addition to the ability to provide power, it can provide these other services to a community that allow them to be more self-sustaining,” says Katherine Young, NREL’s programme manager for geothermal energy. 

Source: BBC

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