The Hazle Spindle flywheel grid frequency regulation project, part of the Smart Grid Demonstration Program (SGDP), is making the grid more reliable at its Humboldt Industrial Park plant in Hazle Township, Pa.
With its $52.4-million cooperative research agreement under the U.S. Department of Energy's Smart Grid Demonstration Program, which provided $24.1 million, the recipient, originally named Beacon Power, was to design, build and operate a utility-scale 20 MW flywheel plant, where power from the electric grid can accelerate the flywheel, which can then return the power to the grid when needed, with few losses. The Beacon Gen4 flywheel is designed to provide 100 kW of output and store 25 kWh of energy. Two hundred flywheels were connected in parallel to provide 20 MW in capacity, spanning a 40 MW range of frequency regulation. The system can fully respond to a grid imbalance in less than four seconds, allowing it to correct short-term unpredictable imbalances in electricity supply and demand. Because the system is mechanical, it can repeatedly operate at 75% depth of discharge with 85% round-trip efficiency, and is sturdy enough so there is virtually no energy degradation over time. The flywheels are built to last at least 20 years, or 100,000 cycles at full rated depth of discharge.