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SANDY — What weighs as much as a Toyota Corolla, spins at thousands of rotations per minute, and, Nate Walkingshaw hopes, might one day live in your backyard and store power to run your home?
It's called flywheel energy storage, and Walkingshaw — a Utah entrepreneur — created a company called Torus to sell the device to store solar and other renewable sources of energy.
"I had no idea that I would have ended up in energy storage at all," said Walkingshaw, who was previously the chief experience officer of Pluralsight.
Walkingshaw stumbled across flywheel energy storage while looking for a way to store hydropower to run water pumps on his family's tree farm, Salt Pyne, in Sandy. He tried car batteries, but they didn't keep their charge in the cold weather.
"Creating power is actually fairly simple. Storing power is hard," he said.
Flywheels — heavy wheels that, by spinning, store kinetic energy — have been used for quite some time with potter's wheels and as sharpening stones. Flywheel energy storage acts like an electrical battery by employing an electric motor to turn the flywheel. To tap into that stored energy, the process is reversed — the wheel turns the motor, which acts as a generator.
Flywheel energy storage systems have been used as uninterruptible power supply devices, and because they can deliver a lot of energy in a very short time, in race cars, roller coasters (such as Lagoon's "Wicked"), aircraft launch systems and physics labs.
"Nobody had really done long duration (flywheel) energy storage before," Walkingshaw said. "Could we make it store its power for days if there was no draw against it?"
Torus is gearing up to sell and install consumer systems with solar panels, inverters, flywheels, and of course, an app to control and monitor it all.
Walkingshaw said one flywheel will provide 10 kilowatt hours of electricity, or a thousand watts for 10 hours. That's not enough to charge your Tesla, but, he said, it can run your home.
In the backyard of a company demo home, a Torus flywheel, encased in a round, green barrel-sized cover, looks like an oversized air conditioner. Because the wheel itself lives in a vacuum and floats on magnets to reduce friction, Walkingshaw said, it will keep spinning for more than two days if no electricity is used.
The advantages of flywheel energy storage systems include a long life; Walkingshaw said Torus' system will last 30 years, and has none of the environmental impacts that come with chemical batteries.
However, with a fast-spinning 2½-ton wheel comes the potential for it to break and explode. Walkingshaw said new materials and monitoring sensors take care of that threat.
"You have to put a ton of telemetry data in a flywheel so it never has a catastrophic failure."
Probably the bigger obstacle is price. Flywheel energy storage systems, including Torus', cost more than chemical batteries. Walkingshaw said he doesn't have an exact price yet, but says it will probably sell, including a solar array and inverter, for about $50,000, installed.
According to some previous energy storage cost analyses, flywheel energy storage doesn't yet stack up price-wise to other storage technologies. Walkingshaw said what Torus is going to sell, once you factor in the product life, will be competitive.
"A flywheel energy storage device lasts 30 years. A chemical battery, you know, depending on discharge and charge rates and the environment that it's in, it can be three years, it can be seven years, but probably the longest, 10 years. So you're gonna have to repurchase that battery three times over the same lifecycle," he said.
Walkingshaw said he wasn't planning on getting into the energy business, but he did because of his four sons.
"If you look at the next 30 or 40 years of their life, and the 30 or 40 years of the life that I had, I think their life looks different than mine, and I think that's climate-related," he said. "I think we do need to find a completely different path with a completely different solution, and it lives in electrification."
Walkingshaw said Torus, which already has a facility in Springville, is in the process of choosing another location in Utah to manufacture the flywheels and hardware.
