Revterra’s kinetic stabilizer offers many benefits for energy storage, from its long lifespan, to its full recyclability, to its high capacity. But the most game-changing feature? It plays nicely with the grid.
The U.S. power grid was built around the frequency of 60 hertz (Hz), kept consistent by gas and steam turbines. This stable frequency—known as grid inertia—is critical for keeping power constant throughout the system and avoiding blackouts.
As the grid shifts to renewables, there’s a problem: renewable energy sources don’t clock in at 60 Hz.
Revterra is solving grid inertia for the energy transition with a new generation of flywheel batteries. These rotor-based systems—which convert electricity into kinetic energy and back again—aren’t novel, but the startup’s tech represents a step change: it is larger and more efficient (enabled by its “passively stable magnetic bearing”), cheaper, and can match 60 Hz by rotating at 3,600 RPM, providing grid inertia and connecting directly to the grid without inverters, converters, or other mechanisms.
“We can be a drop-in replacement for that inertia, with the ultimate goal of enabling 100 percent renewables-powered grids,” says Revterra’s CFO Patrick Flam. “We can help shepherd along the energy transition to cleaner sources, which amounts to gigatons of potential emissions averted.”
The invention can lift heavier masses, resulting in higher energy-storage capacity and reduced costs; primed for industrial applications, each module can provide 2 MW of power and store up to 100 kWh of energy. (Today’s flywheel batteries offer under 30 kWh of energy storage, according to Flam.) Since the lifted masses are heavier, the flywheel doesn’t have to rotate as quickly, allowing it to match the 60 Hz that’s ideal for the U.S. grid. It can also conform to the 50 Hz grid frequency that’s common in other parts of the world.
In all, Revterra says its flywheel tech is on track to be 20 times more efficient than today’s standard, and has a lifetime of over 20 years.
Applications: From AI to EVs
Revterra’s first commercial application is for AI data centers, which are uniquely demanding for the grid.
“These new data centers have collections of incredibly power-hungry graphics processing units (GPUs) that have load profiles associated that are incredibly volatile and unpredictable,” Flam explains. “The GPUs can draw a crazy amount of power, but the real issue is that that power can fluctuate more than 90 percent across one of these GPUs in the course of just milliseconds. That type of power fluctuation is incredibly dangerous for the on-site equipment.”
Acting as an intermediary between the data center’s energy supply and machinery, Revterra’s tech avoids equipment damage and downtime. The kinetic battery can be made of about 98 percent recycled steel and is fully recyclable itself, making it a more sustainable piece of equipment than the lead-acid-battery-supported uninterruptible power supply devices that are used in AI data centers today. It also enables the use of on-site renewable sources, due to its 60 Hz matching.
The Revterra team envisions two future applications for its tech: addressing grid inertia at a major scale and enabling streamlined rollout of EV-charging infrastructure. The latter would involve installing DC fast-charging stations without needing to upgrade the grid to deliver more power.
On the Cusp of Commercialization
The eight-person Revterra team recently completed manufacturing its first commercial unit. It’s now in the testing and validation phase, and will deliver the unit to its first paying customer this year.
Revterra closed an $8.5M Series A in 2022—led by Greentown partners Equinor Ventures and SCF Ventures—and is currently raising a Series A-2. Interested investors and prospective partners can get in touch here.
An Inaugural Greentown Houston Member
Flam was the second employee at Revterra, which was founded by Ben Jawdat in 2017. Jawdat received his Ph.D. in physics from the University of Houston and has completed extensive superconductivity and advanced materials research.
Revterra was an inaugural member of Greentown Houston when it opened in April 2021, and its team is still an active part of the community.
“We’ve benefitted hugely from a few things: the first is the community, being in touch with all of the relevant energy parties across the state and the country, even—we’ve gotten involved in Greentown Boston events on occasion,” Flam says. “We’ve been able to learn and continue our development due to our involvement in Greentown. The second one is the space: we actually started building these devices in our prototype phases in Greentown Houston’s lab. That was instrumental in our development.”