The Texas-based startup Quidnet Power simply accomplished a check exhibiting it may well retailer power for as much as six months by pumping water underground.
Utilizing water to retailer electrical energy is hardly a brand new idea—pumped hydropower storage has been round for over a century. However the firm hopes its twist on the expertise may assist deliver low-cost, long-duration power storage to new locations.
In conventional pumped hydro storage amenities, electrical pumps transfer water uphill, right into a pure or artifical physique of water. Then, when electrical energy is required, that water is launched and flows downhill previous a turbine, producing electrical energy. Quidnet’s strategy as a substitute pumps water down into impermeable rock formations and retains it underneath strain so it flows up when launched. “It’s like pumped hydro, the other way up,” says CEO Joe Zhou.
Quidnet began a six-month check of its expertise in late 2024, pressurizing the system. In June, the corporate was in a position to discharge 35 megawatt-hours of power from the nicely. There was nearly no self-discharge, which means no power loss, Zhou says.
Cheap types of power storage that may retailer electrical energy for weeks or months may assist inconsistent electrical energy sources like wind and photo voltaic go additional for the grid. And Quidnet’s strategy, which makes use of commercially obtainable tools, might be deployed shortly and qualify for federal tax credit to assist make it even cheaper.
Nonetheless, there’s nonetheless an enormous milestone forward: turning the pressurized water again into electrical energy. The corporate is presently constructing a facility with the generators and assist tools to try this—all of the elements can be found to buy from established firms. “We don’t must invent new issues primarily based on what we’ve already developed right now,” Zhou says. “We will now begin simply deploying at very, very substantial scales.”
That course of will include power losses. Power storage methods are sometimes measured by their round-trip effectivity: how a lot of the electrical energy that’s put into the system is returned on the finish as electrical energy. Modeling means that Quidnet’s expertise may attain a most effectivity of about 65%, Zhou says, although some design selections made to optimize for economics will probably trigger the system to land at roughly 50%.
That’s much less environment friendly than lithium-ion batteries, however long-duration methods, in the event that they’re low-cost sufficient, can function at low efficiencies and nonetheless be helpful for the grid, says Paul Denholm, a senior analysis fellow on the Nationwide Renewable Power Laboratory.
“It’s received to be cost-competitive; all of it comes right down to that,” Denholm says.
Lithium-ion batteries, the fastest-growing expertise in power storage, are the goal that new types of power storage, like Quidnet’s, should chase. Lithium-ion batteries are about 90% cheaper right now than they had been 15 years in the past. They’ve grow to be a price-competitive various to constructing new natural-gas crops, Denholm says.
In relation to competing with batteries, one potential differentiator for Quidnet might be authorities subsidies. Whereas the Trump administration has clawed again funding for clear power applied sciences, there’s nonetheless an power storage tax credit score, although lately handed laws added new provide chain restrictions.
Beginning in 2026, new power storage amenities hoping to qualify for tax credit might want to show that not less than 55% of the worth of a undertaking’s supplies are usually not from overseas entities of concern. That guidelines out sourcing batteries from China, which dominates battery manufacturing right now. Quidnet has a “excessive degree of home content material” and expects to qualify for tax credit underneath the brand new guidelines, Zhou says.
The ability Quidnet is constructing is a undertaking with utility accomplice CPS Power, and it ought to come on-line in early 2026.
