Utility-Scale Flywheel Energy Storage & Grid-Tie Inverters

A few days ago Beacon Power announced that their installation of the world’s first 20MW Flywheel plant is currently operating at 18MW, and is expected to be running at its full, 20MW capacity before the end of the month.  We’re pretty excited about this at Oztek, as we provide the controls for both the grid-tie inverter that interfaces with the grid, and the sensorless permanent magnet motor drive used for the flywheel in Beacon’s system.  This program posed many design challenges, and it’s always extremely satisfying to see things finally come together, particularly on something as large and complex as this.

World’s Largest Flywheel Plant in Stephentown, NY

This exciting news was picked up by quite a few sites, and as with any emerging technology, the response seems to be as much confusion as it is appreciation and interest in what it offers.  The Beacon system is not a power generating plant.  Rather, it is a frequency regulation plant that stabilizes the grid by providing power during periods of high demand and storing energy during periods of low demand.  The need for this stems from the fact that power plants cannot rapidly throttle power output to respond to sudden changes in demand.  Elaborate systems have been developed over the years to deal with this that, by their very nature, require a net surplus of power generating and distribution capacity to be built in.  However, these systems still place demands on power generation plants that cause additional wear and tear, and greater production of CO2 and other emissions than if the plants were allowed to operate under more steady-state conditions.  The Beacon system is clean and very efficient, wasting only a small percentage of the energy it processes, and it’s able to respond to large demand changes in seconds.

For those interested in more detail, here’s an interesting article Why Frequency Regulation is Important, as well as a more comprehensive white paper on the subject Frequency Regulation Basics – Oak Ridge NL .