Dream technology for energy storage?

The Department of Energy has announced a $43 million loan guarantee for an advanced energy storage system that works like a dream — if the dreamer is Leonardo DiCaprio’s character, Cobb, from the movie Inception. The system approximates (as best it can in the phenomenological world) the forever-spinning top that was Cobb’s test to tell if he were dreaming or awake.

Inside Beacon Power's 'SuperFly'

The advanced energy storage system in this case is a flywheel, which converts electrical energy into kinetic (spinning) energy, which it then releases, converted back to electricity, as needed. A 20 MW collection of super-efficient flywheels made by the Massachusetts-based Beacon Power Company, will absorb power when there’s excess production on the grid and release it when demand rises again.

The project is under construction in Stephentown, New York, and will provide approximately 10 percent of  that state’s regulation capacity, by reducing the need to increase production at existing power plants when demand spikes — without releasing additional CO2 or soot.

Unlike the top in Inception, the Smart Energy 25 flywheel system, would eventually stop spinning without periodic, if small, jolts of electricity. In the physical world, there’s no such thing as a free energy lunch.

But Beacon’s flywheels come tantalizingly close.

The heart of the system is a lightweight rotating rim made from a carbon-fiber composite. The “top” is levitated on magnetic ball bearings in a vacuum, so that friction is nearly eliminated (it’s that qualifier, “nearly,” that separates the flywheel from Cobb’s totem top). Spinning at a rate of 16,000 rpm, the flywheel can supply peak electrical capacity back to the grid nearly instantaneously — with a ramp-up time measured in nanoseconds, unlike traditional power sources.

Early simple flywheel

In addition to smoothing out the larger power grid and increasing usable energy, Beacon’s flywheels could be a boon for renewable energy sources such as wind and solar. Wind-produced energy is at a maximum at night, solar, during the day. The flywheels could efficiently store this intermittent energy and release it when the wind dies down or, in the case of solar, at night, or when clouds lower electrical production.

Engineers at Beacon continue to look for new ways to lower friction and increase efficiency. Someday, they may reduce drag to zero and produce electricity forever without needing anything more than the initial spin that sets the wheel in motion.

In your dreams.