More than 12 Megawatts of Power Planned to Protect Data Center Operations

AUSTIN, Texas (Sept. 16, 2008) – Active Power, Inc. (NASDAQ: ACPW), inventor and manufacturer of the most energy-efficient critical power systems in the world, today announced that it received its single largest order from one of the world’s largest Internet search engine providers for twelve 1200 kVA CleanSource® UPS (uninterruptible power supply) systems). This 12 megawatt sale utilizes 48 flywheels and will be deployed at one of the customer’s newest domestic data center facilities to protect mission critical IT equipment from power outages. System deliveries are scheduled for 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. Active Power delivers better space and power efficiencies which result in substantial economic savings while at the same time providing a more reliable and green solution.”

An installation of this magnitude could yield up to $1 million per year in electrical and operational savings as compared to the deployment of a conventional, less efficient UPS system. A 10 percent efficiency improvement on twelve 1200 kVA systems can displace approximately 7,500 tons of CO₂ emissions per year, which is the equivalent of removing approximately 1,250 vehicles off the streets every year.

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About Active Power

Active Power (NASDAQ: ACPW) provides efficient, reliable and green critical power solutions and uninterruptible power supply (UPS) systems to enable business continuity in the event of power disturbances. Founded in 1992, Active Power’s flywheel-based UPS systems protect critical operations in data centers, healthcare facilities, manufacturing plants, broadcast stations and governmental agencies in more than 40 countries. With expert power system engineers and worldwide services and support, Active Power ensures organizations have the power to perform. For more information, please visit www.activepower.com.