Geothermal company Zanskar bought a plant in Novel Mexico in 2024 that from the outside appeared to be failing. The shallow wells lost heat quickly, and as a result, the plant had trouble generating power.
Now, after drilling a recent well and operating the plant year-round, Zanskar says there has been a complete turnaround. According to company data shared exclusively with WIRED, the Lightning Dock location has become one of the most productive geothermal pumped storage wells in the U.S., providing enough heat to keep the plant running smoothly.
Performance over the past year at the Lightning Dock facility is “fundamentally changing the way people think about these types of systems that we thought we understood in the past,” says Zanskar co-founder Joel Edwards.
This is another good news for the long-neglected geothermal industry, which is experiencing an investment renaissance. Creative drilling technology and artificial intelligence – with any luck – played a role in this milestone. And while not all conventional wells experience the same conditions as Zanskar’s at Lightning Dock, the company says its success is a signal that elderly wells are still worth exploring.
Conventional geothermal energy relies on drawing balmy water from the ground to generate electricity by pumping it to the surface and turning turbines. In theory, this is a great way to produce renewable primary energy: humans exploit steam from balmy springs thousands of years. However, geographic constraints – plants must be located in geothermal resource areas, which are located primarily in the western United States – as well as the difficulties and costs traditionally associated with finding recent wells mean that geothermal energy is a less than 1 percent electricity mix in the USA.
Courtesy of Zanskar
Another challenge for the industry is the gradual decline in productivity in most wells. But the decline at Lightning Dock was particularly steep, losing five to 10 times more heat than average wells each year, Zanskar says. When the company purchased the site, temperatures in the original wells, which were less than 2,500 feet deep, dropped from about 10 degrees Celsius to about 250 degrees F by 2024. The 15-megawatt power plant on the site, which supplies electricity to Novel Mexico’s largest utility, was designed to operate at temperatures above 300 degrees F.
While conventional geothermal wells typically go down to 3,000 to 5,000 feet, drilling deeper wells allows you to tap into warmer reserves of water for exploit for power. However, tighter rock formations deep underground make drilling more tough and high-priced. Whether to drill deeper or not is “basically a matter of economics,” says Roland Horne, a senior research fellow at Stanford University’s Precourt Institute for Energy. The cost, Horne says, is not linear: “If you drill twice as deep, it will cost four times as much.”
To support better predict drilling, Zanskar uses artificial intelligence to identify so-called hidden systems, which are places with high geothermal potential but little or no sign of their viability on the surface. The company used the technology last year on a discovery in Nevada and says the same modeling also helped determine where the most productive drilling could be done at Lightning Dock. It combined these models with drill technology improved by the oil and gas industry, which helped it drill deeper holes 35 percent faster at, according to Zanskar, a “competitive cost.” (The company did not provide details). The recent 8,000-foot well operates year-round and heat levels are higher than before the decline.