MANY MINDEDQnetic tests an underground carbon-fiber flywheel for long-duration storage
Startup Qnetic is developing an underground flywheel storage system, called Pulsar, aimed at backing wind and solar with up to 12 hours of storage. Headquartered in both the US and China, the company is building what it bills as the world's largest dedicated flywheel test cell at its Shanghai Technology Center — a million-dollar-plus investment — while planning to manufacture the system in the US, starting at a California factory with its Q500 unit.
Flywheels store energy kinetically, spinning a rotor in a vacuum enclosure. EPRI describes Qnetic's rotor as 15 feet tall, made of carbon fiber, and magnetically levitated. The company is currently working on a 200 kilowatt-hour prototype, with plans for a 500 kWh unit followed by a 1,000 kWh unit that would discharge over 4 to 12 hours at 85 percent round-trip efficiency. The US Department of Energy defines long-duration storage as at least 10 hours; pumped hydropower currently holds roughly 95 percent of that US market.
Why it matters: long-duration storage is the piece that lets variable renewables behave like firm power, and a mechanical, mineral-light flywheel avoids the overseas battery supply chains that dominate lithium storage. If the economics hold, it broadens the toolkit for cheap, always-available clean energy.
The caveats are substantial. Qnetic is at prototype and testing stage, not commercial deployment. It has raised $7.1 million over 12 months and holds validation agreements with EPRI and NREL, but its claim of roughly double the revenue of equivalent lithium systems remains unproven, and flywheel scale-up has historically been slow.
Source: CleanTechnica