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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

                                   ----------

                                    FORM 8-K

                                 CURRENT REPORT
                       PURSUANT TO SECTION 13 OR 15(d) OF
                       THE SECURITIES EXCHANGE ACT OF 1934

        Date of Report (Date of earliest event reported): April 26, 2006

                               ACTIVE POWER, INC.
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             (Exact Name of Registrant as Specified in Its Charter)

                                    000-30939
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                            (Commission File Number)

              Delaware                                       74-2961657
    ----------------------------                         -------------------
    (State of Other Jurisdiction                            (IRS Employer
          of Incorporation)                              Identification No.)

       2128 W. Braker Lane, BK12, Austin, Texas                 78758
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      (Address of Principal Executive Offices)                (Zip Code)

                                 (512) 836-6464
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              (Registrant's Telephone Number, Including Area Code)

                                       N/A
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          (Former Name or Former Address, if Changed Since Last Report)

     Indicate by check mark whether the registrant is a shell company (as
defined in Rule 12b-2 of the Exchange Act).

                        [ ]  Yes             [x]  No

     Check the appropriate box below if the Form 8-K filing is intended to
simultaneously satisfy the filing obligation of the registration under any of
the following provisions (see General Instruction A.2. below):

[ ]  Written communications pursuant to Rule 425 under the Securities
     Act (17 CFR 230.425)

[ ]  Soliciting material pursuant to Rule 14a-12 under the Exchange
     Act (17 CFR 240.14a-12)

[ ]  Pre-commencement communications pursuant to Rule 14d-2(b) under the
     Exchange Act (17 CFR 240.14d-2(b))

[ ]  Pre-commencement communications pursuant to Rule 13e-4(c) under the
     Exchange Act (17 CFR 240.13e-4(c))

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ITEM 2.02 RESULTS OF OPERATIONS AND FINANCIAL CONDITION. On April 26, 2006, Active Power, Inc. issued a press release reporting its results of operations for its fiscal quarter ended March 31, 2006. A copy of the press release is furnished herewith as Exhibit 99.1. In accordance with General Instruction B.2 of Form 8-K, the information contained in this Current Report, including the exhibit attached hereto, shall not be deemed "filed" for purposes of Section 18 of the Securities Exchange Act of 1934, as amended, or otherwise subject to the liabilities of that section, nor shall such information be deemed incorporated by reference into any filing under the Securities Exchange Act of 1934, as amended, or the Securities Act of 1933, as amended, regardless of any general incorporation language in such filing, except as shall be expressly set forth by specific reference in such filing. ITEM 9.01. EXHIBITS AND FINANCIAL STATEMENTS. (d) EXHIBITS Exhibit 99.1 Press Release dated April 26, 2006

SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. ACTIVE POWER, INC. Dated: April 26, 2006 By: /s/ Joseph F. Pinkerton III ---------------------------- Joseph F. Pinkerton III Chairman of the Board and Chief Executive Officer

                                                                    Exhibit 99.1

                       PRESS RELEASE DATED APRIL 26, 2006

                           [LOGO OF ACTIVE POWER (R)]

                  ACTIVE POWER ANNOUNCES FIRST QUARTER RESULTS

AUSTIN, Texas (April 26, 2006) -- Active Power, Inc. (NASDAQ: ACPW) today
announced results for its first quarter ended March 31, 2006. Revenue for the
first quarter of fiscal 2006 was $5.6 million, up 62% from the same period last
year and 8% from the previous quarter.

Net loss for the first quarter of 2006 was $6.0 million, or 12 cents per share,
compared to a net loss of $5.3 million, or 12 cents per share, for the same
period last year and a net loss of $6.8 million, or 14 cents per share in the
fourth quarter of 2005. Net loss for the quarter includes expenses of $857,000
or 2 cents per share for stock-based compensation.

Cash and investments usage for the quarter was $5.0 million, as compared to $4.7
million for the same period last year and $6.4 million for the previous quarter.
Cash and investments at March 31, 2006 were $37.0 million.

"We experienced strong year-over-year growth in our core flywheel business in
Q1, driven in part by increased sales of our megawatt-class UPS" said Joe
Pinkerton, Chairman and CEO of Active Power. "Our recently expanded
international sales team came in ahead of plan and we expect this momentum to
continue over the next several quarters. We are seeing increased demand for our
products in all regions due to new data center construction, as evidenced by two
orders totaling 17 megawatts announced earlier this year. Last month we received
UL certification on our CoolAir(TM) DC product and will begin production of
UL-listed units in May."


Recent Business Highlights:
- ---------------------------

     o    Shipped eight megawatt-class UPS systems against the 11-megawatt order
          from Caterpillar announced at the end of January. These flywheel UPS
          systems will be used to protect a large datacenter in the United
          States. We believe the remainder of this order will be shipped in the
          second quarter.

     o    Shipped twelve 500 kW DC flywheel systems pursuant to an order from
          Eaton Powerware announced in February of this year. These DC flywheel
          systems will be used to protect a large datacenter in the United
          States.

     o    Obtained UL certification for our CoolAir DC line of products. CoolAir
          DC is the first minute-for-minute alternative to batteries
          commercially available to the Uninterruptible Power Supply (UPS)
          market. Using thermal energy and breathable room air to provide power,
          a single CoolAir DC unit can provide 85kW of power for up to 15
          minutes and, simultaneously, produce cool air to mitigate heat buildup
          in the protected environment.

o Flywheel unit shipments increased 112% from 43 units, or 11 MW, in Q1 2005 to 91 units, or 23 MW, in Q1 2006. Total flywheel runtime now exceeds 21 million hours. o Received an order and shipped a production-level CoolAir DC unit in April to one of the leading producers of photovoltaic modules in Europe. o Shipped UPS systems to protect the runway lights at three large airports around the world. Outlook: - -------- Active Power expects Q2 2006 revenue to be approximately $5.0 to $6.0 million, and Q2 earnings per share to be a loss of approximately 11 to 13 cents, which includes approximately 2 cents per share for stock-based compensation expenses. We expect cash and investments usage in Q2 to be in the range of $5.5 to $6.5 million. CONFERENCE CALL: The Company will host a conference call today, Wednesday, April 26, at 11:00 a.m. Eastern Time, to further review the Company's fiscal Q1 results. A replay of the webcast will be available until May 10th. Investors may access the live broadcast and replay through our web site: www.activepower.com. ABOUT ACTIVE POWER: Active Power, Inc. (www.activepower.com) designs, manufactures and markets battery-free power quality products that provide the consistent, reliable electric power required by today's digital economy. An ISO 9001-certified company, Active Power is the first to commercialize a flywheel energy storage system, CleanSource(R), that provides a highly reliable, low-cost and non-toxic replacement for lead-acid batteries used in conventional power quality installations. Active Power has also recently developed a new battery-free extended runtime product line (CoolAir(TM)) based on its proprietary thermal and compressed air storage technology.

CAUTIONARY NOTE REGARDING FORWARD-LOOKING STATEMENTS: This release may contain forward-looking statements that involve risks and uncertainties. Among the important factors that could cause actual results to materially differ from those in the forward-looking statements are: the potential for significant losses to continue; inability to accurately predict revenue and budget for expenses for future periods; fluctuations in revenue and operating results; overall market performance; decreases and/or delays in capital spending; limited product offerings; inability to expand and integrate new distribution channels; inability to manage new and existing product distribution relationships; our dependence on our relationship with Caterpillar(R); competition; delays in research and development; dependence on sole or limited source suppliers; inability to increase product sales; inventory risks; dependence upon key personnel; inability to protect our intellectual property rights; potential future acquisitions; potential Sarbanes-Oxley Section 404 compliance issues; the volatility of our stock price regardless of our actual financial performance; and other factors detailed in our filings with the Securities and Exchange Commission. Additional risks and uncertainties that we are unaware of or that we currently deem immaterial also may become important factors that affect us. Active Power expressly disclaims any obligation to release publicly any updates or revisions to the information contained in this press release or to update or revise any forward-looking statements to reflect any changes in expectations, or any change in events or circumstances on which those statements are based, unless otherwise required by law. Active Power and our Active Power logo and CleanSource are registered trademarks of Active Power, Inc. All other trademarks are the properties of their respective companies. ACTIVE POWER CONTACTS: Michael Chibib, Investors, 512.744.9453, mchibib@activepower.com Derek Jones, Corporate Communications, 512.744.9210, djones@activepower.com

ACTIVE POWER, INC. CONDENSED AND CONSOLIDATED STATEMENTS OF OPERATIONS (Thousands, except per share amounts) (unaudited) THREE MONTHS ENDED MARCH 31, ---------------------------- 2006 2005 ------------ ------------ Product revenue $ 5,044 $ 2,931 Service and spares revenue 525 507 ------------ ------------ Total revenue 5,569 3,438 Cost of product revenue 5,137 3,245 Cost of service and spares revenue 576 544 ------------ ------------ Total cost of revenue 5,713 3,789 Gross Margin (144) (351) Operating expenses: Research and development 2,225 2,231 Selling & Marketing 2,659 1,437 General & Administrative 1,494 2,137 ------------ ------------ Total operating expenses 6,378 5,805 ------------ ------------ Operating loss (6,522) (6,156) Interest income 394 378 Gain due to change in market value of investment rights - 493 Other income (expense) 79 (42) ------------ ------------ Net loss $ (6,049) $ (5,327) ============ ============ Net loss per share, basic & diluted $ (0.12) $ (0.12) Shares used in computing net loss per share, basic & diluted 49,183 46,085 Comprehensive loss: Net loss $ (6,049) $ (5,327) Unrealized gain (loss) on investments in marketable securities (84) (101) ------------ ------------ Comprehensive loss $ (6,133) $ (5,428) ============ ============

ACTIVE POWER, INC. CONDENSED AND CONSOLIDATED BALANCE SHEETS (Thousands) March 31, December 31, 2006 2005 ------------ ------------ (unaudited) Assets Current assets: Cash and cash equivalents $ 9,243 $ 7,590 Restricted cash 116 116 Short-term investments in marketable securities 24,751 31,364 Accounts receivable, net 6,207 5,769 Inventories 4,969 4,242 Prepaid expenses and other 494 596 ------------ ------------ Total current assets 45,780 49,677 Property and equipment, net 7,359 7,530 Long-term investments in marketable securities 2,959 2,970 Deposits and other 188 188 ------------ ------------ Total assets $ 56,286 $ 60,365 ============ ============ Liabilities and stockholders' equity Current liabilities: $ Accounts payable $ 1,907 2,264 Accrued expenses 3,508 3,780 Deferred revenue 395 205 ------------ ------------ Total current liabilities 5,810 6,249 Stockholders' equity: Common stock 49 49 Treasury stock (5) (5) Deferred stock compensation - (293) Additional paid-in capital 237,254 235,147 Accumulated deficit (186,738) (180,689) Other accumulated comprehensive income (84) (93) ------------ ------------ Total stockholders' equity 50,476 54,116 ------------ ------------ Total liabilities and stockholders' equity $ 56,286 $ 60,365 ============ ============ # # #