Active Power Provides Preliminary First Quarter 2008 Results

AUSTIN, Texas--(Business Wire)--
Active Power, Inc. (NASDAQ: ACPW), inventor and manufacturer of
the most energy-efficient critical power systems in the world, today
announced preliminary revenues for its quarter ended March 31, 2008,
would be between $7.3 to $7.5 million, compared to previously provided
guidance of $8 to $10 million. In addition, cash used in operating
activities and investments in first quarter 2008 is now expected to be
$5.3 to $5.5 million, compared to previous guidance of $2 to $3
million. At this time, Active Power is unable to update its guidance
on net loss per share as the company is still finalizing results of
its international operations.

"Although we anticipate first quarter revenues to be approximately
20 percent higher than the prior year's results, we have experienced
delays in closing a number of sales opportunities and recognizing
revenue in this period," said Jim Clishem, president and CEO for
Active Power. "These delays were primarily in our European-based
operations. North American sales results were in line with our
expectations. Because many of our expenses are incurred in
anticipation of revenue, cash used in operations will be higher than
previously guided. The increase in cash used in operations and
investment activities compares to the approximately $300,000 used in
operations during fourth quarter 2007. Taken as a whole, total cash
used over the last six months has in fact been in line with
expectations."

Active Power expects to announce first quarter 2008 earnings via
news release on April 25, 2008, and provide more detail via conference
call scheduled for Friday, April 25, 2008, at 10:00 a.m. (CST). A
replay of the Web cast will be available until May 9, 2008. A live,
audio only Web cast and replay of the call will be made available on
the Investor Relations section of the company's Web site at
www.activepower.com.

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. Active Power also offers CoolAir,
the only solution that provides both backup power and backup cooling.
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.

Cautionary Note Regarding Forward-Looking Statements

This release contains forward-looking statements within the
meaning of Section 27A of the Securities Act of 1933, as amended, and
Section 21E of the Securities Exchange Act of 1934, as amended,
regarding our expected financial results, including our revenue and
changes in our cash, for the first quarter 2008. Active Power's first
quarter 2008 financial results, as discussed in this release, are
preliminary and unaudited, and subject to adjustment. The
forward-looking statements in this release are subject to risks and
uncertainties, including the risk that our financial results may vary
based on, among other things, the results of the closing process for
the quarter and discussions with our independent auditors. Please
refer to Active Power filings with the Securities and Exchange
Commission, including its Form 10-K filed on February 29, 2008, for
more information on the additional risks that could affect Active
Power's business or financial results.

Active Power, CleanSource and CoolAir are registered trademarks of
Active Power, Inc. The Active Power logo, PowerHouse and PowerCentre
are trademarks of Active Power, Inc. All other trademarks are the
properties of their respective companies.

Active Power, Austin
Investor Contact:
John Penver, 512-744-9234
Chief Financial Officer
jpenver@activepower.com
or
Media Contact:
Lee Higgins, 512-744-9488
Public Relations Manager
lhiggins@activepower.com

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