Milestones for Flywheel, Lithium Battery Grid-Scale Projects

Energy storage developments got a boost as Beacon Power Corp. in June announced that its first flywheel energy storage plant in Stephentown, N.Y., achieved its full 20-MW capacity, and AES Energy Storage said its Los Andes battery storage system in Chile had performed continuously for more than 18 months as a critical reserve unit for the nation’s northern grid.

World’s First Grid-Scale Flywheel Storage Plant. Massachusetts-based Beacon Power, which has commercially produced and deployed its composite flywheel technology for grid-scale frequency regulation since 2008, this year reached the technical milestone of building the world’s first grid-scale flywheel-based storage plant (Figure 1). The company energized and grid-connected the first 8 MW of flywheel energy storage at the plant in New York in January, and this June, it achieved the full 20 MW, operating 200 high-speed Beacon flywheels to provide frequency regulation services to the New York Independent System Operator (NYISO).

1. Spinning wheels. Beacon Power’s flywheel energy storage plant in Stephentown, N.Y., achieved its full 20-MW capacity this June, using 200 flywheels to provide frequency regulation services to the New York Independent System Operator. Courtesy: Beacon Power

The company’s flagship flywheel technology works essentially as a kinetic battery. At the core of the flywheel is a carbon-fiber composite rim, supported by a metal hub and shaft, with a motor/generator mounted onto the shaft. The flywheel works by accelerating a cylindrical assembly called a rotor, or flywheel, to a very high speed. It maintains the energy in the system as rotational energy, and finally converts the energy back to electrical energy by slowing down the flywheel.

“When charging (or absorbing energy), the flywheel’s motor acts like a load and draws power from the grid to accelerate the rotor to a higher speed,” Beacon says on its website. “When discharging, the motor is switched into generator mode, and the inertial energy of the rotor drives the generator which, in turn, creates electricity that is then injected back into the grid.”

Multiple flywheels may be connected together to provide various megawatt-level power capacities. The flywheel’s performance is 5 MWh (20 MW up or down for 15 minutes), and the “round-trip” efficiency is approximately 85% terminal to terminal, including all components.

The company plans to follow the $69 million New York plant with a similar 20-MW merchant plant in Hazle Township, Pa. The New York project was developed with a $43 million loan guarantee from the U.S. Department of Energy, and the company has received a $24 million federal smart grid stimulus grant for the Pennsylvania project, which is estimated to cost $53 million. Beacon says it is “working to secure the remaining financing” before it breaks ground this fall.

Lithium-Ion Battery System for Grid Reliability. AES Corp.’s energy storage arm, AES Energy Storage, also made a June announcement that its 12-MW Los Andes battery energy storage system in the Atacama Desert, Chile (Figure 2), has been performing continuously for more than 18 months as a critical reserve unit for Chile’s northern grid. Grid operator CDEC-SING reported that the project is the only reserve unit that has responded to all generator-assisted fault restorations since January 2010, and that during that time, it demonstrated a response speed higher than other units.

2. Recharging its batteries. AES Energy Storage, which has built and is operating several commercial lithium-ion battery systems, in June marked a milestone for its 12-MW Los Andes battery energy storage system in the Atacama Desert, Chile. The frequency regulation and spinning reserve project began operations in November 2009. Courtesy: AES Energy Storage

AES Energy Storage also said in a press release that the lithium-ion battery storage system—developed in conjunction with A123 Systems, Parker Hannifin, and ABB—has enabled AES Gener (an AES Chile-based generation company) to increase power generation from its 277-MW Norgener coal/petcoke power plant by 4%. Lithium for the battery was sourced from northern Chile, where the Los Andes system is located.

The project essentially monitors the condition of the power system, and if a significant frequency deviation occurs, such as the loss of a generator or transmission line, the Los Andes system provides up to 12 MW of power “nearly instantaneously,” claims AES. “This output can be maintained for 20 minutes at full power, allowing the system operator to resolve the event or bring other standby units online.”

AES Energy Storage has several similar plants under development around the world. The company commercially operates an 8-MW lithium-ion battery system at Johnson City, N.Y., adjacent to a coal plant, supplying frequency regulation to NYISO. The project will this year be enlarged by 12 MW, bringing it to 20 MW. The AES project will eventually use 800,000 batteries, each roughly the size of a D cell, installed in 53-foot shipping containers. AES in December finalized a loan guarantee with the DOE for the project. In addition to a 1-MW project in Pasadena, Texas, to support the Electric Reliability Council of Texas market, the company has pilot-scale projects in commercial operation in Norristown, Pa. (for PJM), Huntington Beach, Calif. (for the California Independent System Operator), and a pilot project in Indianapolis, Ind.

Meanwhile, a 32-MW lithium-ion battery project is under construction at the AES Laurel Mountain Wind Farm in Bellington, W.Va., to supply frequency regulation in the PJM market. That project could also come online this year. AES has also said it will begin construction on another 20-MW project in northern Chile near a new Angamos thermal power plant. That system could also begin operations later this year.

—Sonal Patel is POWER’s senior writer.