Mt. Princeton Geothermal’s proposed initial test drilling site. Photo courtesy of Mt. Princeton Geothermal.
Since Part III of Ark Valley Voice’s coverage of geothermal energy development near Buena Vista was published on August 18, there have been a few questions raised by readers in our comment section. We received questions about possible energy production capacity, what exactly is a binary power plant, drill depths and fracking, and government funding of geothermal projects.
We appreciate the willingness of our readership to engage with us on points of concern and after a long series like the one on geothermal, a follow-up article like this was always in the cards. In this article, we will attempt to clarify a few points in quick, easily perusable succession.
We’ve called this a temporary wrap-up because, even though this is the final part in a series of explanatory articles on geothermal as it stands today, the project as a whole is still in its infancy and thereby has years’ worth of news making left to occur.
Energy Production
At the risk of sounding like a broken record, no one can know what the productive capacity of a geothermal plant off of Rodeo Road and CR 123 can be until resource testing is undergone. The scientists with Mt. Princeton Geothermal (MPG) have predicted, based on over a decade’s worth of non-invasive testing, that a power plant of 10 MW capacity might be possible at the location.
This is five times the productive capacity of Trout Creek Solar, which currently supplies about 4.7 percent of Sangre De Cristo Electric Association’s (SDCEA) electricity. That could mean power for up to 6,000 homes, and it would not be limited by the sun’s incessant rising and setting.
3,692 acres of land owned by the Colorado State Land Board, leased to Mt. Princeton Geothermal for geothermal exploration. Not pictured: the important stuff, approximately 6,000 ft below the surface. Photo by August Toevs.
Of course, as it stands, the terms of SDCEA’s contract with Tri-State Generation and Transmission—the company that provides most of the electricity transmitted by SDCEA—limit the amount of electricity generation that SDCEA can produce. It is capped, at the moment, at 5 percent.
The Trout Creek installation makes up most of that 5 percent and private solar makes up for the rest, so if a plant were to be built tomorrow, it is unlikely SDCEA would be able to take full advantage.
However, the actual timeline is not so short. By the time a productive facility could be built, it is likely that Tri-State will have renegotiated its contract with rural electric co-ops like SDCEA.
According to those familiar with Tri-State’s generation portfolio and service area, a handful of co-ops have already begun submitting projects to Tri-State that exceed the 5 percent generation limit. Tri-State has also made a number of commitments towards carbon neutrality in the coming decades that would make them amenable to something like a geothermal facility since it would help them reach those goals on paper.
Hank Held of MPG said the company is in talks with both SDCEA and Tri-State as to the transmission of any energy generated by MPG, but was unable to share details of these conversations.
What’s a Binary Power Plant?
There was some confusion as to what a binary power production facility is and how it relates or does not relate to fracking. In a binary system, geothermal water is used to heat a working fluid with a low boiling point, such as isopentane (boiling point 82 degrees Fahrenheit) which turns a turbine and produces power. The two fluids do not mix, and the water is typically reinjected into the ground where it will become hot again. The isopentane is cooled, condensed, and then reheated in order to keep the turbines running.
This differs from fracking because fracking is the intentional fracturing of rocks deep in the ground to increase the permeability of a given resource, usually natural gas. One can reinject water into the ground without fracturing rock. It takes a great deal of pressure to fracture rocks; a degree of pressure that would be incredibly difficult to produce by accident.
There are aspects of geothermal energy that do involve fracturing rock intentionally. Enhanced geothermal techniques are employed when a company fractures subterranean rocks to increase the permeability of heat instead of natural gas. “Enhanced” techniques allow for shallower wells to have a greater capacity for heat production. However, fracking is only undergone in the construction phases of a plant, not the production phases.
What’s more, nobody can know at this moment whether enhanced techniques are necessary at this time. But if the water is as hot as early testing seems to indicate, enhanced techniques are unlikely to be utilized.
Drill Depths and Other Measurements
While Ark Valley Voice would certainly like to be able to provide specific data points regarding the test well’s characteristics, without resource testing and a contractor’s bid/project outline, those data points aren’t available. In general terms, a gradient test well (typically the first stage of testing) would likely be far shallower than 1,500 feet. Most gradient wells barely reach a depth of 450 feet. The width of its borehole is variable, depending on what type of rig is used to drill it, but they tend to only be around seven inches wide, give or take.
Intermediate testing phases demand deeper drilling, usually into the actual reservoir of geothermal water itself. This, again, is dependent on a project’s inevitable peculiarities, but one can expect that depth to be somewhere in the ballpark of 6,000 feet. For scale, private wells for drinking water or irrigation are much, much shallower, ranging from about 50 to 200 feet.
Governmental Exploitation of Funds
One reader levied an accusation against local governance in response to the last article, saying the geothermal plant is only being pursued so that “county officials [can] get their hands on government money.” No county officials are involved in the project right now. MPG is a private organization. Any government grants provided for test wells would then go to MPG, not to the county or county officials.
I read all 4 articles again, and I have to say that I am still opposed to this idea. We don’t need it, at all.
First of all, this isn’t the middle of nowhere, Greenland, where you could build this thing and bother almost nobody. This is planned to be built right where people live! The risks it poses to the water supply, the environment, and quality of life are unacceptable, as are all of the “maybe” and “possibly” type answers given by the proponents when faced with difficult questions about noise, pollution, and aquifer contamination or degradation.
I was still curious about the risks, so I googled “geothermal risks”. This was interesting. From the State of Colorado Fish and Game people –
Fish and Wildlife Considerations
Air and water pollution are two leading environmental issues associated with geothermal energy technologies. Additional concerns are the safe disposal of hazardous waste, siting and land subsidence. Most geothermal power plants require a large amount of water for cooling or other purposes. This need could raise conflicts with other users or uses such as fish spawning and rearing in areas where water is in short supply. Steam vented at the surface may contain hydrogen sulfide, ammonia, methane and carbon dioxide. Dissolved solids discharged from geothermal systems include sulfur, chlorides, silica compounds, vanadium, arsenic, mercury, nickel and other toxic heavy metals. All of these releases, if concentrated, can create localized fish and wildlife kills. Geothermal resource development is often highly centralized, so reducing their environmental impacts to an acceptable level is achievable.
Then I read this, in one of the articles here –
“Aquifer contamination is a risk inherent to geothermal resource tapping. It is with any subterranean resource, geothermal or otherwise. It falls to conscientious citizens and elected officials to make sure that any project in Colorado adheres to and properly satisfies the environmental provisions of a permitted activity.”
It certainly does sound to me like there are real risks involved with this proposal. A couple things I’d like to see are some real answers from the proponents, not just squishy crap like “we think”, “probably”, etc., when asked about the most concerning aspects of their proposal, and also some indication that the County Commissioners are more concerned about protecting our environment and our aquifer than they are about quietly advocating for a power plant that we do not need.
Some people say that corporations are people, and I agree – corporations are frequently the equivalent of sociopaths, and generally only care about quarterly profits and the bottom line. Some corporations will do or say pretty much anything to enhance and protect their bottom line, including using convoluted corporate structures to hide from their responsibilities, selling out to people who care even less about the promises made to the community, or in some cases where the corporation is run by folks who lack morals, actual criminal acts with the goal of enhancing profits or avoiding regulatory compliance.
You’ll have to excuse me if the fact that the proponents don’t have any “current” plans for enhanced geothermal isn’t as reassuring as they hope it is. We all know that they could just change the plan, or sell the project to someone else who cares even less about the environment or following laws and regulations. Then, after an expensive lawsuit or two where the county is outgunned and outspent by energy industry lobbyists, we would have enhanced geothermal production happening in Chaffee County.
Again, I’d love to see an article that explores the financial angle of this proposal. Who stands to profit, and to what degree, from this dumb idea?
August, I’ve been a geologist for 50 some odd years and your article was very well done. There’s a lot of misapprehension about this process but I think the most telling thing that you brought up was the fact that saying greater Crystal will be prohibited from using any of this energy in our valley. True that may change, but it is unlikely.
Thanks for the very intelligent presentation.
The amount of government money that MPG will get for this project will be spread through the county government officials like manure. You are very thorough at presenting your side of the issue. The pushback on this project is just as well researched and committed.
Debra Zinik
Buena Vista, CO
Debra, thank you for your comment. If you have any specific questions about the geothermal exploration, we’re happy to research them. However, to clarify, Ark Valley Voice does not have a “side” in this. Reporter August Toevs has reported the facts of this issue and his articles represent extensive research on his part.
We believe that attempts to malign our county officials are simply out of line. The state statutes clearly set out the process by which a company applies for and obtains a test site permit, the process with proof of concept, then the years-long return for state input, before any application might come before the BoCC. Concern, certainly is a valid emotion, but the manure being spread is not by county officials, or by AVV. We in the news media are often tough on local governments, but in this case at this time, the commissioners have no role.
Isopentane. Please take a moment to read about it. Toxic. Hazardous. A threat to the environment.
Is dumping Isopentane into a 6000-ft well at the base of Mt. Princeton justified by its advocates’ ability to play the “green energy” card?
Reminds me of the Vietnam War major who explained that “In order to save the village we had to destroy it.”
I’m not in favor of this experiment, mainly because it is not needed, and because of the location, but the impression I got from the article is that the isopentane is contained in the system. It is not being injected into the ground. Well, at least not until there is some kind of problem that results in the release of isopentane into the environment at the base of Mt. Princeton.
The idea that we need this thing really baffles me. I’d like to see an article that researches and identifies all of the individuals and businesses who stand to benefit financially from this entire process, from conception of the idea all the way to the eventual completion and operation of the power plant itself.