In the latest sign of growing interest in flywheels, Active Power, Inc. (ACPW) this week reported its largest single order to date. The company said that "one of the world’s largest Internet search engine providers" had bought 12 of Active Power's 1200 kVA CleanSource UPS (uninterruptible power supply) systems using 48 flywheels. The systems are scheduled to be delivered in the fourth quarter 2008.

“This particular customer’s order further substantiates the market acceptance of high performance and high efficiency flywheel UPS solutions for large mission critical data center applications,” said Jim Clishem, president and CEO of Active Power. “We continue to see rapid adoption of our flywheel technology particularly among major data center owners and operators who recognize the value proposition and performance benefits inherent with systems of this design.”





A flywheel is a spinning cylinder which generates power from kinetic energy, and continues to spin when grid power is interrupted. In most data centers, the UPS system draws power from a bank of large batteries to provide "ride-through" electricity to keep servers online until the diesel generator can start up and begin powering the facility.

Advocates of flywheel technology say they are preferable to batteries, and can address most data center power interruption scenarios. Flywheel-based UPS systems also take up considerably less space than battery banks, and may be gaining traction due to interest in "green" data center designs.