Texas-based startup Quidnet Power simply accomplished a take a look at exhibiting it could retailer vitality 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 might assist carry low cost, long-duration vitality storage to new locations.
In conventional pumped hydro storage services, 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 beneath stress so it flows up when launched. “It’s like pumped hydro, the wrong way up,” says CEO Joe Zhou.
Quidnet began a six-month take a look at of its expertise in late 2024, pressurizing the system. In June, the corporate was capable of discharge 35 megawatt-hours of vitality from the nicely. There was nearly no self-discharge, which means no vitality loss, Zhou says.
Cheap types of vitality storage that may retailer electrical energy for weeks or months might assist inconsistent electrical energy sources like wind and photo voltaic to go additional for the grid. And Quidnet’s strategy, which makes use of commercially obtainable tools, may very well be deployed rapidly and qualify for federal tax credit to assist make it even cheaper.
Nevertheless, there’s nonetheless a giant milestone forward: turning the pressurized water again into electrical energy. The corporate is at the moment constructing a facility with the generators and assist tools to do this—all the parts can be found to buy from established corporations. “We don’t must invent new issues based mostly on what we’ve already developed at the moment,” Zhou says. “We are able to now begin simply deploying at very, very substantial scales.”
That course of will include vitality losses. Power storage programs are usually measured by their roundtrip effectivity: how a lot of the electrical energy that’s put into the system is returned on the finish as electrical energy. Primarily based on modeling, Quidnet’s expertise might attain a most effectivity of about 65%, Zhou says, although some design decisions made to optimize for economics will possible trigger the system to land at roughly 50%.
That’s much less environment friendly than lithium-ion batteries, however long-duration programs, 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 quickest rising expertise in vitality storage, are the goal that new types of vitality storage, like Quidnet’s, should chase. Lithium-ion batteries are about 90% cheaper at the moment than they had been fifteen years in the past. They’ve turn out to be a price-competitive different to constructing new pure gasoline vegetation, Denholm says.
With regards to competing with batteries, one potential differentiator for Quidnet may very well be authorities subsidies. Whereas the Trump administration has clawed again funding for clear vitality applied sciences, there’s nonetheless an vitality storage tax credit score, although lately handed laws added new provide chain restrictions.
Beginning in 2026, new vitality storage services hoping to qualify for tax credit might want to show that at the very least 55% of the worth of a undertaking’s supplies will not be from overseas entities of concern. That guidelines out sourcing batteries from China, which dominates battery manufacturing at the moment. Quidnet has a “excessive degree of home content material” and expects to qualify for tax credit beneath 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.
