Leading us through a tour of the Peppermill’s geothermal plant, John Kassai, the central plant and geothermal manager, invited us to lay our hands on a large pipe connected to the ground. Once we touched the pipe, warmth ran through.
Reaching 4,400 feet below the ground, the Peppermill harnesses the Earth’s natural heat in order to heat the casino’s water and power the casino’s internal heating. This has saved the Peppermill millions of dollars in energy use, returning the investment of developing the geothermal plant in just three years.
Nearly 15 years ago, the Peppermill started tapping into the vast Moana Reservoir, holding natural geothermal energy more than three quarters of a mile underground. It took the Peppermill Resort $9.7 million to develop their geothermal heating system.
Although it was a risky decision to move forward with the project, which was initiated during the Great Recession, the project has saved the Peppermill an estimated $2.2 million in natural gas bills each year while drastically reducing the casino’s carbon footprint by 12,000 metric tons of CO2 emissions per year.
Geothermal energy is the heat that the earth contains. Northern Nevada is abundant with geothermal energy due to its unique composition of earth and geographic location.
Other companies like Ormat Technologies have also made use of these geothermal sources. Ormat’s plants at Steamboat Hills power homes in Galena. The Moana Reservoir powers the Moana Springs Community Aquatic & Fitness Center.
Maria Richards, the interim director of Great Basin Center for Geothermal Energy, resides in an office on UNR campus, with maps on the walls, and a UC Santa Cruz Banana Slugs mug, filled with hot tea on her desk.
She explains that the Great Basin is constructed of a thin layer of crust above the mantle. The Great Basin is an area that spreads 200,000 square miles west of the Rocky Mountains and east of the Sierra Nevadas. The water of the region drains inside the region itself, with no outlet into the ocean. Its expanse includes most of Nevada, half of Utah, and parts of Idaho, Wyoming, Oregon, and California.
Maria Richards pointing to the Great Basin on a map that is hung up in the Great Basin Center for Geothermal Energy. On the map there are points marking where geothermal power plants and hot spots are located.
The Great Basin being next to the Pacific Tectonic Plate causes much tectonic activity to occur inside the basin’s earth. The pull-apart, land-stretching activity creates passageways for the heat to travel up through the thin crust where it can be reached by drill or even make its way to the surface.
Geothermal energy is a renewable form of energy. Theoretically, sources of geothermal energy can continue to produce energy eternally. The degree of renewability a geothermal source may have depends on a balance of give and take from the resource.
Geothermal energy relies on the fluids that carry the heat through the crust. If the same amount of fluids that were taken from the source are replenished in the system, or if the fluids entirely remain in the system, the source may be able to produce geothermal energy infinitely.
The Peppermill follows this renewable format by keeping the water that carries its geothermal heat kept in a closed loop system. This relieves the challenge of replenishing the system.
At the Peppermill, these pipes bring the geothermal water from the pumps, through the heat exchangers, and back down into the Earth.
Also on UNR’s campus is Jim Faulds, director of the Nevada Bureau of Mine and Geology, whose office is populated by work-related achievements and paperwork. Faulds explains that passageways of the energy can close overtime. Rock material on fault lines are eroded down into small clay particles. The geology world calls this process clay gouging. This clay material fills passageways, making them impermeable and inaccessible.
This process is more common in larger faults than in smaller faults, Faulds explains. Given this, Faulds seeks out young and small faults in hopes of the faults being active and long-lasting.
“It’s the heat beneath our feet,” he says, “Why not use it?”
To locate subsurface hotspots, Faulds explains geologists deploy LiDAR (Light Detection and Radar) technology. Airplanes deflect laser beams off the Earth’s surface, resulting in high-resolution topographic images. These images help paint the picture of what’s going on beneath the surface, like which areas have higher potential conductivity or will allow for a more rapid flow of electrical currents.
Richards from Great Basin Center for Geothermal Energy explains that geothermal energy produces more heat with a higher temperature differential within the closed loop of fluid. Due to this, Richards is in favor of mixed incorporation of geothermal sources with other renewables like solar.
She says that when a geothermal source produces its least amount of energy due to the sun heating the ground, a solar source is producing its most amount of energy from absorbing the rays.
This contrasts with the Peppermill’s central plant and geothermal manager, John Kassai’s opinion on solar energy.
”Solar is overrated,” he says.
Kassai criticizes solar’s productivity and consistency in comparison to renewables like geothermal and nuclear energy. He states the Peppermill will not be incorporating solar into its power supply in the near future.
Kassai explains how he can watch over all of the heat production from the Pepermill geothermal operations from this computer
Geothermal’s consistency is reliable, as outside factors like consistent wind or sunlight are not crucial to its production. Nevada is second in the U.S. for most geothermal energy production, behind California.
Thanks to these geographical advantages, Faulds suggests that UNR’s campus could soon be powered by geothermal energy. Faulds says it could become a significant financial benefit to the university if it was willing to invest the time and necessary upfront resources. UNR’s campus suffers occasional power outages, like one that occurred in late April, so it could be worthwhile to explore alternative options.
However, the development of geothermal energy is an increasingly expensive investment.
Richards was just in Gabbs Valley, a mountain range in the west of the central Nevada desert in the Great Basin region for a geothermal drilling project.
“We were drilling a well that we wanted to get to 50 feet and it was already $30,000,” says Richards.
Another challenge with geothermal energy is the loud noise it creates.
Richards explains the geothermal wells have mufflers because of the amount of noise and volume associated with water raising to the surface.
“It’s like the roar of the Earth,” says Richards, “I like to think the Earth is talking to us through geothermal.”
During the Peppermill’s drilling process, engineers put up large sound barriers to prevent hotel guests and the neighboring residential areas from hearing the noise of the geothermal plant.
Kassai explains that it is more difficult for businesses to invest in geothermal development now, because drilling costs have risen since the Peppermill’s construction of its own geothermal plant.
The Peppermill is still happy to boast about its decision to drill and develop its own geothermal system.
Despite the costs, a recent analysis from the U.S. Department of Energy Geothermal Technologies Office's (GTO) GeoVision found that geothermal electricity generation has the potential to increase at least 26-fold by 2050, with northern Nevada one of its possible hubs.