Green Patent Acquisitions: Private Equity Firm Snaps Up Beacon Power’s Flywheels


Beacon Power is a Massachusetts company that makes flywheel-based energy storage systems.

Rockland Capital, a private equity firm, recently purchased Beacon Power, including a Stephentown, New York, flywheel plant project. The purpose of the project is to allow excess energy from the grid to be stored at the plant, and then re-emitted at a later time when energy demand increases.

According to Cleantech PatentEdge™, Beacon Power Corporation is listed as the owner of record on 69 U.S., European, and international (PCT) patents and published applications.

U.S. Patent No. 6,614,132 (’132 Patent), entitled “Multiple flywheel energy storage system,” describes an energy storage system comprising a plurality of flywheel systems, while U.S. Patent No. 8,008,804 (’804 Patent) is entitled “Methods, systems and apparatus for regulating frequency of generated power using flywheel energy storage systems with varying load and/or power generation” and describes how frequency can be regulated using flywheels.

In the invention of the ’132 Patent, each flywheel energy storage system unit (100) generates kinetic energy by spinning at a constant rate and drives a motor/generator (104). According to Beacon’s web site, the company’s Smart Energy 25 flywheel can rotate at speeds of up to 16,000 rpm.

A bi-directional inverter (108), which can convert AC to DC power and vice-versa, is connected to the motor/generator (104). These components are then linked to a control processor (112) that can control the power output of the system.

A connector circuit combines each of the systems. In a Beacon Smart Energy Matrix, 10 flywheels are connected.

The ’804 Patent relates to methods for regulating the AC frequency of the electrical power to be supplied by the flywheels to the grid.

By tracking long-term variations in the power being utilized by the grid, it can then be determined when it would be best to have the flywheels in either power-generating or power-absorbing mode. Thus, if the grid is in need of more energy, the flywheels can shift into power-generating mode.

Article by Rosemary Ostfeld. Rosemary recently completed both her undergraduate and graduate education at Wesleyan University in Middletown, Connecticut. She double majored in Biology, and Earth & Environmental Sciences as an undergraduate, and received her Master’s in Earth & Environmental Sciences.

Article appearing courtesy Green Patent Blog.



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