Geothermal Energy is Trending, But Boise Residents Have Enjoyed it Since the 1890s

Geothermal energy for heating and cooling is quickly moving toward mainstream adoption. While many are just beginning to understand geothermal’s renewable energy potential, we thought it would be fun to visit America’s first geothermal system built in Boise, Idaho, in 1890 – the same year Idaho became the 43rd state. Oklahoma had just become a territory. Meanwhile, Edison’s electric lamp and incandescent lightbulb, the Ferris Wheel, the Tesla coil, and the rotary dial telephone would all have to wait another year to be launched and publicized.

That same geothermal system is still a great source of pride in Boise today.

Snapshot

Through a 20-mile network of underground pipes that stretch from nearby foothills to downtown Boise, the city’s geothermal energy system provides clean, emissions-free heating to over 100 buildings, totaling 6 million square feet of indoor space.

In Boise, you can wash your clothes in a geothermal-heated laundromat, swim at the YMCA in a geothermal-heated pool, stroll snow-free streets on geothermal-heated sidewalks, and buy flowers grown in a geothermal-heated greenhouse. And it’s been this way for quite some time.

Listen to Tina Riley from City of Boise on Supercool

What Makes Geothermal Desirable?

Innovation is underway across residential, commercial, utility, and municipal approaches to this carbon-free thermal energy source that flows constantly below the surface (please find a list of recent geothermal projects below). 

In short, geothermal energy is always available, assuming the project planning phase called for enough wells; it’s a 24/7, always-on heating and cooling source. Installing these systems requires a minimal footprint compared to today’s most common forms of energy production like coal, nuclear, wind, and solar. It’s also silent, and requires little to no maintenance, particularly in the case of a closed-loop system like the one in Boise, where hot water is taken from and ultimately returned to the nearby aquifer after it’s circulated through the pipes, homes, city sidewalks, and buildings downtown. 

The U.S. military sees strategic advantages in geothermal energy because of its continuous, always-available characteristics. The Pentagon’s Defense Innovation Unit has contracted six next-generation advanced geothermal startps to pilot systems on military bases in Alaska, California, Idaho, Texas, and Nevada. Beyond generating abundant local energy that requires minimal surface space, geothermal eliminates the vulnerabilities of long, snaking supply lines required by fossil fuels.

World’s First Geothermal System

In addition to its scale, the geothermal system in Boise is also exceptional for being the world’s first.

Above: The original Artesian Hot and Cold Water Company Pumphouse, photo courtesy of Wikipedia

According to the 1979 nomination form to the National Register of Historic Places,

“The Artesian Hot and Cold Water Company pumphouse is significant in the areas of architecture, engineering, and energy because the surviving structure was built to accommodate Idaho’s pioneer application of a natural hot water heating system. Commercial geothermal power systems soon followed in Italy (1904), New Zealand, Iceland, Mexico, Salvador, Japan, and Russia, as well as in one or two other places in the United States, including a similar space heating arrangement in Klamath Falls, Oregon, and a major electric power development in Lake County, California.”

The nomination form also describes the system’s utility thusly, “The uses of the geothermal resource were both public and private. Boise became a well-known resort with the opening of her elaborate Natatorium in 1892. Fine homes were built along Warm Springs Avenue after the Natatorium and a connecting streetcar line were completed.”

The Boise Natatorium, ‘The Nat’ for short, opened in May of 1892, intended as a destination at the eastern end of a new, dedicated trolley line on Warm Springs Avenue. Designed with a Moorish Revival style, it communicated the uniqueness of the structure, which included a 125-foot-long swimming pool (geothermally heated), a 40-foot high artificial waterfall with a diving platform at one end, and a two-story copper slide. The resort also offered diversions for the whole family: dining room, clubrooms, saloon, gymnasium, baths, dance floors, card rooms, and a tea room.

This must have been a fantastic spectacle at the time. The Nat was conceived and built by C.W. Moore, founder of the Boise Artesian Hot & Cold Water Company, to assure the public of the virtues and reliability of geothermal technology. He also built an elegant home along Warm Springs Avenue, which started a trend among affluent Boiseans who did the same. While the theme park shut down in the 1930s, Moore made his point, as many of these homes still run on geothermal today.

Above: The Boise Natatorium, photo courtesy of the Idaho State Historical Society

The Boise Natatorium, ‘The Nat’ for short, opened in May of 1892, intended as a destination at the eastern end of a new, dedicated trolley line on Warm Springs Avenue. Designed with a Moorish Revival style, it communicated the uniqueness of the structure, which included a 125-foot-long swimming pool (geothermally heated), a 40-foot high artificial waterfall with a diving platform at one end, and a two-story copper slide. The resort also offered diversions for the whole family: dining room, clubrooms, saloon, gymnasium, baths, dance floors, card rooms, and a tea room.

A fantastic spectacle at the time, The Nat was conceived and built by C.W. Moore, founder of the Boise Artesian Hot & Cold Water Company, to assure the public of the virtues and reliability of geothermal technology. He also built an elegant home along Warm Springs Avenue, which started a trend among affluent Boiseans who did the same. While the theme park shut down in the 1930s, Moore made his point, as many of these homes still run on geothermal today.

Boise’s Geothermal System Today

Tina Riley manages the geothermal energy system for the City of Boise and summed up the crux of the system on the Supercool podcast, “It’s essentially a well that pumps the water out, then we have pipes that funnel the water about five feet into individual buildings into a heat exchanger that takes the heat off the water to create the energy that’s used within buildings. That water, then five feet in [to a building], flows right back out again with a collection line that just then funnels straight back down to our injection well and straight back into the same aquifer. So it’s actually a really simple design.”

When asked about the economics of the system, Tina explained, “We have what we call an enterprise fund at the city, so it’s just a self-sustaining financial fund that generates revenue through [the] sale of water. We sell water by the hundred gallons, and that is what generates the revenue that enables us to run the system. Essentially, it’s a utility. So, a building owner downtown that has this system for heat currently pays 36 cents per 100 gallons of hot water. And that ends up being quite comparable to natural gas rates.”

Many building owners who’ve had access to the system have also put in supplementary heat pumps, which lift the system’s efficiency, bringing costs down below legacy utility rates.

Part of that enterprise fund also goes toward maintaining the system. Tina explained that maintenance primarily involves replacing pipes below ground, which requires digging up a street section by section as necessary. The city replaced much of the original piping decades ago, much of which is again being upgraded.

Tina said, “The original pipe that got put in the ground at that point in time was a form of cement, and now what we use has a much longer shelf life of 70 to 100 years versus 40 years. The [new] materials we use are helping to reduce maintenance time, resources, costs, etc.”

Tina arrived in Boise after two decades working in the oil and gas industry for ExxonMobil as a geologist on multiple continents. Her experience helped her transition into the low-carbon economy. It speaks volumes about the future of geothermal and other related industries, specifically that there is a place for people with transferable skills from oil and gas to get into these growing aspects of the energy industry or to work in the public sector in general. Tina also mentioned that her former colleagues have expressed interest in her current role, and she believes they, too, will find that their skills are in high demand as professionals from all industries get pulled into the clean economy.

Tina summed up her experience and personal and professional transition to working for the City of Boise, “I wanted to be part of something that made a difference in my local community. And having a positive impact on something that my kids were going to get to enjoy for a long time to come. So it’s actually a really big shift from a more global organization and a very global career to something really local. And I’m loving it. I love having an impact within my local community.”

Five Modern Geothermal Projects 

While the system that runs under Boise is a striking, early example of geothermal technology, more modern systems are often referred to as next-gen geothermal – like Enhanced Geothermal Systems (EGS) and Advanced Geothermal Systems (AGS) – which aim to create conditions for geothermal energy in places where the natural conditions that support geothermal projects in areas like Boise, simply don’t exist.

Here is a quick list of five recent Supercool geothermalfeature differing appraoches.

The World’s Largest Geothermal Energy Plant.
The Geysers is located north of San Francisco, comprising 18 power stations across 45 square miles. At a total capacity of 900MW, The Geyser produces enough energy to power a million homes in Northern California, demonstrating the potential of geothermal energy at scale.

New England’s Largest Fossil Fuel Energy Utility Shifts to Geothermal.
In Framingham, Massachusetts, the first district geothermal energy system in the U.S. built by a fossil fuel company is about to deliver heating and cooling to thirty-seven residences and commercial buildings. Eversource Energy, the largest natural utility in the region, can show the oil and gas industry how to participate in and profit from the transition to a clean energy economy.

A mammoth, Texas-sized High school in Forth Worth Gets 4,000 Geothermal Wells.
In Fort Worth, 4,000 new wells are already in the ground but weren’t drilled for oil. Instead, they’re tapping underground water for a newly opened high school heated and cooled by geothermal energy. That clean, abundant, renewable energy will ensure that the school’s separate basketball, gymnastics, dance, and cheer gyms are comfortable for the home team and their competition.

Four thousand wells is a striking number. But Fort Worth’s Ever Lake High School is not the first to embrace geothermal. That honor goes to Richardsville Elementary School in Kentucky, which did it in 2010. One thing that the elementary school has never had is an energy bill.

Dandelion Energy Removes the Guesswork from Residential Geothermal.
When your Google reviews read, “Customer service, project manager, scheduling, and install team are all great,” you’re doing something right. Dandelion provides turnkey geothermal systems that replace existing air conditioning and heating equipment, and a heat pump is used to move heat safely between the earth and homes. The company maintains a great list of resources to understand the costs of installing and operating a geothermal system.

Fervo is Taking Grid-Connected Geothermal to Another Level.
A Houston-based geothermal company is adopting drilling techniques developed by the oil and gas industry to go where no geothermal company has gone before, which is to say, really, really deep. In 2023, Fervo completed a successful geothermal project with Google in Nevada in which the company drilled two wells 8,000 feet below ground and then extended them horizontally to access previously inacccessible sources of heat. The result is a novel, utility-scale geothermal solution that taps clean energy reserves for the 21st century and beyond.

Projects, companies, and technologies like these represent the vanguard of geothermal innovation that’s poised to propel the industry’s growth. At present, about 8,500 people are directly employed in the U.S. geothermal industry industry. Still, that figure doesn’t acount for the geologists, biologists, lawyers, surveyors, engineers, architects, site managers, office staff, and others who support the industry.

At Supercool, we see an new underground economy developing that will help build the low-carbon economy. Key among its technologies are pneumatic waste removal systems, heat waste recovery systems, and, of course, geothermal.

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