Outside the small town of Pierce, Colorado, a group of old wells were shut down six years ago when they stopped producing oil. But a startup now wants to repurpose the wells for a geothermal energy system that could help heat local homes.
Building new geothermal power—a type of clean energy that uses heat from underground to produce electricity or heating and cooling—is usually expensive because of the need to drill deep below the ground. That’s why Gradient Geothermal wants to reuse existing wells.
“If you can remove the cost of drilling through the use of facilities that are already there, you go a long way toward making geothermal a really inexpensive way to access the heat that’s in the earth,” says Benjamin Burke, Gradient’s CEO.
The wells on the site are 9,000 feet deep. The amount of heat at a given depth varies depending on location—Nevada, for example, has more geothermal potential than Colorado. But the site in Pierce “is at a depth where there’s plenty of heat for the town,” Burke says.
Gradient Geothermal is one of several companies to get state grants to test various approaches to adding geothermal energy in Colorado. Over the next several months, the startup will be studying the feasibility of the system for the site, looking at what it would take to build, how many buildings it can support, the cost, and the potential greenhouse gas emissions reductions. Already, the company has piloted the reuse of oil wells on another 40-year-old oil field in Nevada that’s still in operation; in that case, the energy is being used to help power the oil company’s operations.
In Pierce, when the oil wells shut down, they were producing only around 2% oil and 98% hot water. If Gradient’s plan moves forward as it envisions, it will harness that hot water and send it to a central facility where the heat is exchanged with a separate system of pipes that run in a network around the town, heating and cooling homes and other buildings, including a school and a meatpacking plant. (The geothermal power will also provide a small amount of electricity to power the company’s own operations.)
Even the town’s sidewalks could potentially be heated, removing snow and ice in the winter. Gradient is partnering with other companies that helped design a geothermal heating network for Colorado Mesa University. Installing the piping would be relatively inexpensive, Burke says, and the project could likely be supported through a mix of funding, including state and nonprofit grants.
“Right now [the town] heats with predominantly natural gas, and sometimes wood stoves,” says Johanna Ostrum, Gradient Geothermal’s COO. “So, our goal here is to provide a benefit, create an opportunity for the town, and really build a pathway for emissions reduction.”
Operating a geothermal plant uses similar skills as working in oil and gas, Ostrum says, and the facility could provide new local jobs for people who previously worked in the oil industry. “The town is looking for growth and new businesses, so they view this as an opportunity to develop and potentially add new jobs,” she says.
In a separate project that also received a state grant, a company called Geothermal Technologies is exploring the possibility of drilling new geothermal wells on a local dairy farm to help provide electricity for the town.
Gradient’s feasibility study will run until next fall, and then the project would have to get funding to move forward. But the model could eventually be replicated. Chevron, which owns the oil field, is partnering on the project with an interest in potentially using the approach on some of its other sites, some of which might also be able to help power nearby communities.
“A lot of the oil fields in the United States have small towns in and amongst them,” Ostrom says. By some estimates, there are between 2 million and 3 million abandoned oil wells in the U.S.
