Use these links to rapidly review the document
TABLE OF CONTENTS

Table of Contents

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of
the Securities Exchange Act of 1934 (Amendment No.    )

	Filed by the Registrant ý
	Filed by a Party other than the Registrant o
	Check the appropriate box:
	o		Preliminary Proxy Statement
	o		Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))
	ý		Definitive Proxy Statement
	o		Definitive Additional Materials
	o		Soliciting Material Pursuant to §240.14a-12

Power-One, Inc.
(Name of Registrant as Specified In Its Charter)
(Name of Person(s) Filing Proxy Statement, if other than the Registrant)
Payment of Filing Fee (Check the appropriate box):
ý		No fee required.
o		Fee computed on table below per Exchange Act Rules 14a-6(i)(1) and 0-11.
		(1)		Title of each class of securities to which transaction applies:
		(2)		Aggregate number of securities to which transaction applies:
		(3)		Per unit price or other underlying value of transaction computed pursuant to Exchange Act Rule 0-11 (set forth the amount on which the filing fee is calculated and state how it was determined):
		(4)		Proposed maximum aggregate value of transaction:
		(5)		Total fee paid:
o		Fee paid previously with preliminary materials.
o		Check box if any part of the fee is offset as provided by Exchange Act Rule 0-11(a)(2) and identify the filing for which the offsetting fee was paid previously. Identify the previous filing by registration statement number, or the Form or Schedule and the date of its filing.
		(1)		Amount Previously Paid:
		(2)		Form, Schedule or Registration Statement No.:
		(3)		Filing Party:
		(4)		Date Filed:

---

Table of Contents

740 CALLE PLANO
CAMARILLO, CALIFORNIA 93012

March 30, 2011

Dear Stockholders:

        It is our pleasure to invite you to the 2011 Annual Meeting of Stockholders of Power-One, Inc. ("Power-One" or the "Company") to be held on May 3, 2011 at the Courtyard Marriott, 4994 Verdugo Way, Camarillo, California 93012 at 8:00 a.m., pacific daylight time. At the meeting we will discuss the items of business described in the enclosed Notice of Annual Meeting and will also report on the Company's business operations. A representative of Deloitte & Touche LLP, Power-One's independent registered public accounting firm, will also be present and will have the opportunity to make a statement to our stockholders and respond to their questions.

        Your vote is important, regardless of the number of shares you own. We hope you can personally attend the meeting and vote your shares but if you are unable to do so, it is still important that you be represented. We urge you to follow the voting directions on the enclosed proxy card and cast your vote as soon as possible. We have enclosed a postage-prepaid envelope for your convenience if you choose to submit a proxy by mail.

        As indicated on the enclosed Notice of Annual Meeting, in addition to the customary actions of electing the members of the Board of Directors of Power-One (the "Board of Directors" or the "Board") and ratifying the appointment of our independent registered public accounting firm, at this year's Annual Meeting, stockholders will be asked to approve an amendment to the Company's Amended and Restated 2004 Stock Incentive Plan, an advisory resolution on the compensation of our named executive officers, and an advisory resolution on the frequency of future named executive officer compensation advisory votes. Each of these proposals is described in the enclosed Notice of Annual Meeting and in detail in the enclosed proxy statement.

        Whether or not you plan to attend the Annual Meeting, please complete, sign and date the accompanying proxy card and return it in the enclosed prepaid envelope. You may revoke your proxy at any time before the Annual Meeting by delivering a notice of revocation dated later than the date of your returned proxy card, submitting a later dated proxy over the telephone or by mail or voting in person at the Annual Meeting. Attendance at the Annual Meeting does not, by itself, revoke the earlier proxy.

        Thank you in advance for your prompt attention to voting your shares.

		Sincerely,
		Tina D. McKnight Secretary

Your Vote is Important.
Please execute and return the enclosed proxy promptly or
submit a proxy by telephone,
whether or not you plan to attend the Annual Meeting

---

Table of Contents

740 CALLE PLANO
CAMARILLO, CALIFORNIA 93012

---

NOTICE OF ANNUAL MEETING OF STOCKHOLDERS

TO BE HELD ON MAY 3, 2011

---

        The 2011 Annual Meeting of the Stockholders of Power-One, Inc., a Delaware corporation ("Power-One" or the "Company"), will be held at the Courtyard Marriott, 4994 Verdugo Way, Camarillo, California 93012, on May 3, 2011 at 8:00 a.m., pacific daylight time, for the following purposes:

(1)

For the holders of the Company's common stock to elect the seven Common Stock Directors named in the accompanying proxy statement, and the holders of the Company's Series A Convertible Preferred Stock to elect the two Preferred Stock Directors named in the accompanying proxy statement, in each case to serve one-year terms ending at the 2012 Annual Meeting of Stockholders or until such person's successor is elected and qualified or such person's death, retirement, resignation or removal;

        (2)   To approve an advisory resolution on named executive officer compensation;

(3)

To conduct an advisory vote on the frequency of future advisory votes on named executive officer compensation;



(4)

To approve the proposed amendment to the Amended and Restated Power-One, Inc. 2004 Stock Incentive Plan;



(5)

To ratify the appointment of Deloitte & Touche LLP as Power-One's independent registered public accounting firm for the 2011 fiscal year; and



(6)

To transact any other business which may be properly presented at the 2011 Annual Meeting and any adjournment(s) or postponement(s) thereof.

        The close of business on March 7, 2011 has been fixed as the record date for determination of stockholders entitled to notice of and to vote at the 2011 Annual Meeting and any adjournment(s) or postponement(s) thereof. A proxy statement, a form of proxy, and the Company's 2010 Annual Report on Form 10-K are enclosed with this Notice.

        A list of stockholders entitled to vote at the 2011 Annual Meeting will be open to the examination of any stockholder for any purpose relevant to the 2011 Annual Meeting during ordinary business hours at the Company's principal executive offices located at 740 Calle Plano, Camarillo, California for a period of 10 days prior to the 2011 Annual Meeting and will be available at the meeting for such purpose.

        Stockholders are cordially invited to attend the 2011 Annual Meeting. Each stockholder, whether or not they expect to be present in person at the 2011 Annual Meeting, is requested to SIGN, DATE and RETURN THE ENCLOSED PROXY in the accompanying postage pre-paid envelope or to submit a proxy by telephone as promptly as possible.

		BY ORDER OF THE BOARD OF DIRECTORS
		Tina D. McKnight Secretary

March 30, 2011

---

Table of Contents

TABLE OF CONTENTS

		Page
INFORMATION ABOUT THE ANNUAL MEETING AND VOTING		4
PROPOSAL ONE: ELECTION OF DIRECTORS		8
RECOMMENDATION		14
CORPORATE GOVERNANCE		15
STANDING COMMITTEES OF THE BOARD		17
DIRECTOR COMPENSATION		24
PROPOSAL TWO: ADVISORY RESOLUTION ON NAMED EXECUTIVE OFFICER COMPENSATION		25
RECOMMENDATION		27
PROPOSAL THREE: ADVISORY VOTE ON THE FREQUENCY OF FUTURE ADVISORY VOTES ON EXECUTIVE OFFICER COMPENSATION		27
RECOMMENDATION		28
COMPENSATION DISCUSSION AND ANALYSIS		28
COMPENSATION COMMITTEE REPORT ON EXECUTIVE COMPENSATION		37
EQUITY COMPENSATION PLAN INFORMATION		37
EXECUTIVE OFFICERS		38
SUMMARY COMPENSATION TABLE		39
GRANTS OF PLAN BASED AWARDS—FISCAL 2010		39
OUTSTANDING EQUITY AWARDS AT FISCAL 2010 YEAR-END		42
OPTION EXERCISES AND STOCK VESTED—FISCAL 2010		43
NONQUALIFIED DEFERRED COMPENSATION		44
PENSION BENEFITS		44
EMPLOYMENT, SEVERANCE AND CHANGE IN CONTROL AGREEMENTS AND ARRANGEMENTS FOR FISCAL YEAR 2010		44
PROPOSAL FOUR: AMENDMENT OF THE AMENDED AND RESTATED 2004 STOCK INCENTIVE PLAN		48
RECOMMENDATION		55
PROPOSAL FIVE: RATIFICATION OF THE APPOINTMENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM		55
RECOMMENDATION		55
AUDIT COMMITTEE REPORT		56
COMPENSATION COMMITTEE INTERLOCKS AND INSIDER PARTICIPATION		58
BENEFICIAL OWNERSHIP OF POWER-ONE, INC. COMMON STOCK		58
SECTION 16(a) BENEFICIAL OWNERSHIP REPORTING COMPLIANCE		61
CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS		62
FINANCIAL AND OTHER INFORMATION		63
IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE STOCKHOLDER MEETING TO BE HELD ON MAY 3, 2011		63
APPENDIX A—THE AMENDED AND RESTATED POWER-ONE, INC. 2004 STOCK INCENTIVE PLAN		A-1

3

---

Table of Contents

INFORMATION ABOUT THE ANNUAL MEETING AND VOTING

        This proxy statement is furnished in connection with the solicitation by the Board of Directors of Power-One, Inc. ("Power-One" or the "Company") of proxies for the matters to be voted on at the 2011 Annual Meeting of Stockholders, which will be held at the Courtyard Marriott, 4994 Verdugo Way, Camarillo, California 93012 on May 3, 2011 at 8:00 a.m., pacific daylight time, and any adjournment(s) or postponement(s) thereof.

        This proxy statement, the Notice of the 2011 Annual Meeting and the form of proxy were first mailed to stockholders on or about March 31, 2011.

Proposals to be Considered

        At the Annual Meeting, the Company will ask its stockholders to:

(1)

if you are a holder of common stock, elect the seven Common Stock Directors named herein, and if you are a holder of Preferred Stock, elect the two Preferred Stock Directors named herein, in each case to serve one-year terms ending at the 2012 Annual Meeting of Stockholders or until such person's successor is elected and qualified or such person's death, retirement, resignation or removal;



(2)

adopt an advisory resolution on named executive officer compensation;



(3)

conduct an advisory vote on the frequency of future advisory votes on named executive officer compensation;



(4)

approve the proposed amendment to the Amended and Restated Power-One, Inc. 2004 Stock Incentive Plan (the "2004 Plan");



(5)

ratify the appointment of Deloitte & Touche LLP as Power-One's independent registered public accounting firm for the 2011 fiscal year; and



(6)

transact any other business that may be properly presented at the Annual Meeting and any adjournment(s) or postponement(s) thereof.

        If any other matters should properly come before the Annual Meeting or any adjournments or postponements of the Annual Meeting, the persons named as proxies in the enclosed proxy card will vote the proxies in accordance with their best judgment regarding the best interests of the Company's stockholders. If it becomes necessary to solicit additional proxies, the persons named as proxies in the enclosed proxy card will vote the proxies in accordance with the recommendation of the Board of Directors to adjourn and postpone the Annual Meeting.

Recommendations of the Board of Directors

        The Board of Directors recommends that the stockholders vote "FOR" the election of the Common Stock Director nominees named herein for membership on the Board of Directors, "FOR" the advisory resolution on named executive officer compensation, "FOR" conducting future advisory votes on named executive officer compensation "EVERY TWO YEARS", "FOR" the proposed amendment to the 2004 Plan, and "FOR" the ratification of the appointment of Deloitte & Touche LLP to serve as the Company's independent registered public accounting firm for the 2011 fiscal year.

This Proxy Solicitation

        If you have questions about the 2011 Annual Meeting, including the procedures for voting your shares, you should contact Power-One's Corporate Secretary at 740 Calle Plano, Camarillo, CA 93012, and (805) 987-8741, extension 4561.

4

---

Table of Contents

        The Company will bear all costs of soliciting proxies, including reasonable mailing expenses incurred by brokers to obtain the votes of the beneficial owners of stock held in a broker's name or in the names of nominees. The Company has retained the services of Phoenix Advisory Partners for a fee of $7,500 plus reimbursement of expenses to assist in the solicitation of proxies for the Annual Meeting.

Quorum

        To establish a quorum necessary to conduct business at the Annual Meeting, a majority of the voting power of the outstanding shares of Common Stock and Preferred Stock must be represented, in person or by proxy, at the Annual Meeting. Broker non-votes and abstentions will be counted as present for purposes of establishing a quorum. Broker non-votes refer to situations where shares are held in "street" form through a broker or similar market intermediary rather than in the stockholder's own name and the broker or similar market intermediary is not instructed by the stockholder on how to vote. If you hold shares in street name and do not provide your broker with specific voting instructions, under the rules of the NASDAQ, your broker may generally vote on routine matters but cannot vote on non-routine matters. Proposals 1, 2, 3, and 4 are considered non-routine matters. Therefore, if you do not instruct your broker how to vote on Proposals 1, 2, 3, and 4, your broker does not have the authority to vote on those proposals. Proposal 5 is considered a routine matter and, therefore, broker non-votes are not expected to exist on that proposal.

        As of March 7, 2011, the record date for the determination of stockholders of the Company entitled to notice of and to vote at the 2011 Annual Meeting, the Company had 107,143,546 shares of common stock, $0.001 par value per share (the "Common Stock"), and 23,625 shares of Series A Convertible Preferred Stock, $0.001 par value per share (the "Preferred Stock"), outstanding and entitled to vote. The holders of the Preferred Stock vote as a single class with the holders of Common Stock on an as-converted basis on any matter to come before the stockholders other than the election of the Common Stock Directors, provided, however, that in the event that any holder of Preferred Stock, together with its affiliates would hold in aggregate more than 19.9% of the voting power of the Company or more than 19.9% of the total shares of Common Stock then outstanding upon conversion of the Preferred Stock to Common Stock, such holder's and such holders' affiliates' collective voting interest will be capped at 19.9%. Each holder of Common Stock at the close of business on March 7, 2011 will be entitled to one vote for each share held of record. As of March 7, 2011, the aggregate shares of outstanding Preferred Stock are convertible into 17,500,000 shares of Common Stock.

Votes Required

        Proposal 1 (Election of Directors).    To be elected as a Common Stock Director, a nominee must receive the affirmative vote of a plurality of the votes cast, subject to the Company's Majority Voting Policy. Under the Company's Majority Voting Policy, for a Common Stock Director nominee to be eligible for nomination for election or re-election to the Board, whether in a contested or uncontested election, the nominee must deliver to the Board, an irrevocable resignation letter conditioned upon such nominee's failure to receive, in an uncontested election, a greater number of votes cast in favor of such nominee's election than the number of votes withheld from such nominee's election ("Majority Vote") and to resign upon acceptance of such resignation of the Board. Broker non-votes with respect to the election of one or more directors will not be counted as a vote cast and, therefore, will have no effect on the vote. Abstentions will similarly have no effect on the vote. Each of the two Preferred Stock Director nominees are elected by the holders of Preferred Stock, which are both affiliates of Silver Lake Sumeru.

        Proposal 2 (Advisory Vote on Executive Named Executive Officer Compensation).    The approval, on an advisory basis, of the compensation of our named executive officers requires the affirmative vote of a majority of the voting power of the shares of Common Stock and Preferred Stock, voting together as

5

---

Table of Contents

a single class, represented at the Annual Meeting and eligible to vote on thereon. Abstentions will have the same effect as a negative vote, while broker non-votes will not be counted as a vote cast and, therefore, will have no effect on the vote.

        Proposal 3 (Advisory Vote on the Frequency of Future Named Executive Officer Compensation Votes).    The approval, on an advisory basis, of the frequency of holding future named executive officer compensation votes requires a majority of the voting power of the shares of Common Stock and Preferred Stock, voting together as a single class, represented at the Annual Meeting and eligible to vote thereon. Stockholder may vote in favor of holding future named executive officer compensation votes every year, every two years or every three years, or may choose to abstain. Abstentions will have the same effect as a negative vote, while broker non-votes will not be counted as a vote cast and, therefore, will have no effect on the vote.

        Proposal 4 (Approval of Amendment of 2004 Plan).    The approval and adoption of the amendment to the 2004 Plan requires a majority of the of the voting power of the shares of Common Stock and Preferred Stock, voting together as a single class, represented at the Annual Meeting and eligible to vote thereon. Abstentions will have the same effect as a negative vote, while broker non-votes will not be counted as a vote cast and, therefore, will have no effect on the vote.

        Proposal 5 (Ratification of Independent Registered Public Accounting Firm).    The ratification of the appointment of Deloitte & Touche as the Company's independent registered public accounting firm for fiscal 2011 requires a majority of the voting power of the shares of Common Stock and Preferred Stock, voting together as a single class, represented at the Annual Meeting and eligible to vote thereon. Abstentions will have the same effect as a negative vote.

Other Matters

        The Company is not aware of any business other than the matters described in this proxy statement and in the Notice of Annual Meeting that will be presented for consideration or action by the stockholders at the Annual Meeting.

Submission for Stockholder Proposals for the 2012 Annual Meeting

        Power-One anticipates that the 2012 Annual Stockholders' Meeting will take place on May 1, 2012. Any stockholder that satisfies the Securities and Exchange Commission's (the "SEC") requirements for submission of a proposal and that wishes to submit a proposal, including a proposed director nominee, should do so in writing on or before December 2, 2011 if they wish the proposal to be considered timely for inclusion in the proxy statement and form of proxy for the 2012 Annual Stockholders' Meeting. The proposal must include the information required by the Company's Bylaws and must be submitted to the Corporate Secretary of Power-One, Inc. at:

Power-One, Inc.
Attn: Corporate Secretary
740 Calle Plano
Camarillo, California 93012

        The Company's proxy holders reserve discretion to vote in the manner deemed appropriate by the Board of Directors with respect to timely filed proposals. Stockholder proposals to be presented at an Annual Meeting of Stockholders but not submitted for inclusion in the proxy statement for that meeting must be received by the Company's Corporate Secretary at the above address not less than 90, nor more than 120 days prior to the meeting. However, if less than 100 days' notice or public disclosure of the date of the meeting is given or made to stockholders, then notice by the stockholder of any proposal need only be received by the close of business on the 10^th day following the day on which notice of the meeting was mailed or such public disclosure was made. Stockholder proposals must

6

---

Table of Contents

contain information required by Section 2.10 of the Company's Bylaws and comply with applicable legal requirements. Power-One's Bylaws are available via the "Corporate Governance" link found under the main "Investor Relations" link at www.power-one.com. The information on our website is not incorporated by reference into this proxy statement. Alternatively, any stockholder may obtain a copy of the Company's Bylaws by submitting a written request to the Corporate Secretary at the above address. Any proposals received prior to the Annual Meeting that are appropriate for consideration by the Board of Directors and business properly raised at the Annual Meeting of Stockholders will be voted by the proxy holders in the manner deemed appropriate by the Board of Directors.

Stockholder Nomination of a Common Stock Director

        To make a recommendation for a Common Stock Director nominee, a holder of Common Stock must provide notice to Power-One's Corporate Secretary at the above address in accordance with the notice provisions for stockholder proposals set forth above. The notice shall contain (a) as to each person whom the stockholder proposes to nominate for election or reelection as a director, (i) the name, age, business address and residence address of the person, (ii) the principal occupation or employment of the person, (iii) the class and number of shares of capital stock of the Company which are beneficially owned by the person and (iv) any other information relating to the person that is required to be disclosed in solicitations for proxies for election of directors pursuant to Schedule 14A under the Securities Exchange Act of 1934, as amended; and (b) as to the stockholder giving the notice (i) the name and record address of the stockholder and beneficial holder, if any, and (ii) the class and number of shares of capital stock of the Company which are beneficially owned by the stockholder. The Company may require any proposed nominee to furnish such other information as may reasonably be required to determine the qualification of the proposed nominee to serve as a Common Stock Director of the Company. No person shall be eligible for election as a Common Stock Director unless nominated in accordance with the procedures set forth herein. The chairman of the meeting shall, if the facts warrant, determine that a nomination was not made in accordance with the foregoing procedure, and if he should so determine, he shall so declare to the meeting and the defective nomination shall be disregarded. Only the holders of the Preferred Stock may nominate a Preferred Stock Director.

Delivery of Proxy Materials to Security Holders Sharing an Address.

        Pursuant to the rules of the SEC, the Company will deliver only a single copy of the Company's Annual Report on Form 10-K and this proxy statement to multiple stockholders sharing an address unless the Company has received contrary instructions from a stockholder. Upon written or oral request, the Company will promptly deliver a separate copy of the Annual Report and/or this proxy statement to any stockholders at a shared address to which a single copy of the documents was delivered. Stockholders may notify the Company of their requests by calling or writing the Corporate Secretary at:

Power-One, Inc.
Attn: Corporate Secretary
740 Calle Plano
Camarillo, California 93012
Phone: (805) 987-8741, ext. 4561

        Stockholders currently receiving multiple copies of the Annual Report and proxy statement at a shared address and who wish to receive only a single copy in the future may direct their request to the phone number and address indicated above.

7

---

Table of Contents

PROPOSAL ONE

ELECTION OF DIRECTORS

        Pursuant to our Certificate of Incorporation, the Board of Directors by resolution adopted by the affirmative vote of the entire Board of Directors has the authority to set the size of the Board, provided that the number of directors not be less than three nor greater than nine. In accordance therewith, our Board of Directors has set its size at nine members, seven of which are to be elected by the holders of our Common Stock and two of which are to be elected by the holders of our Preferred Stock. Each of the current Common Stock Directors is recommended for re-election to the Board and has agreed to stand for re-election. Other than Richard Thompson, none of the nominees is a current employee of Power-One. If elected, each nominee will serve a one-year term until the next Annual Meeting of Stockholders or until such person's successor is elected and qualified or such person's death, retirement, resignation or removal. It is anticipated that the holders of the outstanding Preferred Stock will elect Kyle Ryland and Ajay Shah as the Preferred Stock Directors to serve until the 2012 Annual Meeting of Stockholders.

        Unless otherwise directed, the persons named in the proxy intend to vote all proxies "FOR" the election of each of the Common Stock Director nominees listed below. If, at the time of the Annual Meeting, any nominee is unable or declines to serve as a director, the discretionary authority provided in the enclosed proxy will be exercised to vote for a substitute candidate designated by the Board of Directors, unless the Board of Directors passes a resolution to reduce the Board's size. The Board of Directors has no reason to believe any of the nominees will be unable or will decline to serve if elected.

Director Qualifications

        The Board believes that its directors should satisfy a number of qualifications, including demonstrated integrity, a record of personal accomplishments, a commitment to participation in Board activities and other traits discussed below in "Our Director Nominations Process." While the Board has no formal policy with respect to diversity, the Board also endeavors to have a diverse membership that represents a range of skills and depth of experience in areas that are relevant to and contribute to the Board's oversight of the Company's global activities. Following the biographical information for each director nominee, we describe the key experience, qualifications and skills that the director brings to the Board that are important in light of the Company's businesses and structure. The Board considered the experience, qualifications and skills of each director in reaching its decision to recommend the Common Stock Directors for re-election. Below are qualifications that the Board feels are essential for service on the Power-One Board of Directors:

•

the ability to devote sufficient time and attention to the responsibilities of serving on the Board of Directors of a publicly traded company;



•

training and experience in a function or discipline relevant to the business and operations of the Company (e.g., technology, manufacturing, finance, law, international operations, marketing), or in a market or business that represents a material portion of the Company's revenue (e.g., Renewable Energy or Power) or in other areas that would enhance the effectiveness of the Board of Directors;



•

awareness of and commitment to act in the best interests of the Company's stockholders; and



•

a demonstrated record of ethical conduct and sound business judgment established by service for a period of not less than five (5) years in an executive position with a corporation or as a practicing licensed professional, in each case involving substantial responsibility and leadership.

8

---

Table of Contents

        There are also specific skills and qualities that the Board believes one or more of its directors should have. It is not expected that any single candidate possess all of the listed skills but rather that the Board as a whole includes members who collectively possess the below listed skills and qualities:

•

Financial Acumen.  Directors should have financial knowledge and at least one or more directors should have experience that qualifies such directors as a "financial expert" under the Sarbanes-Oxley Act of 2002 and the rules and regulations of the SEC and NASDAQ.



•

Key Area Expertise.  The Company seeks to recruit directors that have a range of in-depth knowledge and experience as a senior executive within a key area of a for profit company (e.g., finance, operations, engineering, sales and marketing).



•

Industry Specific Experience.  As a leading high technology company and the world's second largest designer and manufacturer of inverters, the Company seeks directors who have knowledge of and experience in technology, particularly in the renewable energy and power fields, and that have an understanding of Power-One's products, customers and markets.



•

International Operations, Sales or Marketing Experience.  Power-One has a global presence with manufacturing operations on three continents and sales worldwide. Accordingly, international operations, sales and/or marketing experience is important for our directors to have, especially as we continue to expand globally and develop new channels of distribution.



•

Domestic and International Public Policy Experience.  We believe that it is important for our directors to have domestic and international public policy experience in order to help us address significant public policy issues, adapt to different business and regulatory environments and facilitate our work with governments all over the world.



•

Public Company Board Experience.  Directors who have served on other public company boards can offer advice and perspective with respect to board dynamics and operations, relations between the board and management and other matters, including corporate governance, executive compensation and oversight of strategic, operational and compliance-related matters. We believe that the director candidates nominated below collectively possess the described qualifications and that each of them contribute to a strong and cohesive Board of Directors.

9

---

Table of Contents

Independent Common Stock Director Nominees(1)

---

(1)

Independence as determined by the Board under the NASDAQ Rules

Kendall R. Bishop Age 72 First Elected to Board—2000 Occupation: Retired Partner of O'Melveny & Myers LLP		Mr. Bishop was elected to the Board in 2000. In January 2004, Mr. Bishop retired as a partner of the O'Melveny & Myers LLP law firm after 38 years of service. During his tenure at O'Melveny & Myers, he specialized in mergers & acquisitions, public offerings, SEC reporting and advising boards of directors and was head of O'Melveny's office in Paris, France from 1974 to 1977 and the head of its Century City office from 1990 to 2000. Mr. Bishop received his B.A. from Stanford University and his J.D. from the University of California at Berkeley. 2010 Committees: Compensation Committee, Chairman                                Audit Committee                                Nominating and Corporate Governance Committee         Qualifications: Mr. Bishop's experience in corporate legal matters spans more than three decades and includes advising both public and private companies in corporate governance and other legal matters, including sophisticated business transactions. His knowledge of securities regulations and his background in executive compensation, as well as his historic knowledge of the Power-One business, provide valuable insight and direction to the Board and the executive management team.
Jon Gacek Age 50 Occupation: President and Chief Operating Officer, Quantum Corporation		Mr. Gacek was appointed to the Board of Directors and as Chairman of the Audit Committee on November 17, 2008. Mr. Gacek currently serves as the President and Chief Operating Officer at Quantum Corporation, a global storage company specializing in backup, recovery and archive solutions. Prior to joining Quantum, Mr. Gacek served as the Chief Financial Officer of Advanced Digital Information Corporation ("ADIC"), a provider of Intelligent Storage™ solutions for the open systems marketplace, which was acquired by Quantum in 2006, from 1999 to 2006, and he also led ADIC's operations from 2004 to 2006. Before joining ADIC, Mr. Gacek was an audit partner at PricewaterhouseCoopers LLC. He received a B.A. from Western Washington University and is a Certified Public Accountant. The Board has determined that Mr. Gacek qualifies as an audit committee financial expert, as defined under SEC rules and regulations, and that he meets the NASDAQ listing requirement under Rule 5605(c)(3) of having the requisite financial sophistication based upon his employment experience. Mr. Gacek also serves on the board of directors of Market Leader, Inc. (NASDAQ: LEDR), which he joined in 2006, and he currently serves on its Audit Committee. He served as a director of Loud Technologies, Inc. from 2003 until September 2009. 2010 Committees: Audit Committee, Chairman                                Compensation Committee         Qualifications: Mr. Gacek's financial expertise and global operations background bring unique and current experience to the Board, as well as insight related to financial and operational strategies. His experience in serving as the Chief Financial Officer of a publicly listed technology company, as well as his experience with an independent public accounting firm, qualify him to serve as Chairman of the Audit Committee and as the committee's financial expert under the SEC rules and listing standards of the NASDAQ, and enable him to provide important guidance to both management and the Board with respect to disclosure and reporting requirements. Mr. Gacek also has valuable knowledge of corporate governance and compensation and related public company experience from his service on the Boards of other companies.

10

---

Table of Contents

Kambiz Hooshmand Age 49 First Elected to Board—2009 Occupation: Former President and Chief Executive Officer of Applied Micro, Inc.		Mr. Hooshmand was appointed to the Board of Directors on October 21, 2009. From March 2005 until May 2009, Mr. Hooshmand was the President and Chief Executive Officer of Applied Micro, Inc., a communications processor company that he transformed into a leading provider of communication processors and high speed connectivity solutions. Prior to joining Applied Micro, Mr. Hooshmand held several executive positions with Cisco Systems from 1996 until 2005. Mr. Hooshmand received his B.S.E.E./C.S. from California State University, Chico and his M.S. in Engineering Management from Stanford University. Mr. Hooshmand has served as a director of Infinera (NASDAQ: INFN) since December 2009 and currently serves as its Chairman and as a member of its Compensation Committee and the Nominating and Governance Committee. 2010 Committees: Audit Committee                                Compensation Committee         Qualifications: Mr. Hooshmand has extensive experience in the technology and communications industries as well as an extensive engineering background, enabling him to provide the Board with unique insight regarding the Company's strategy and operations. Through his senior leadership positions, including his experience as President and Chief Executive Officer of Applied Micro, Mr. Hooshmand provides direction and advice to the Board and to senior management regarding the challenges inherent in managing a complex organization and leading a technology based business.
Mark Melliar-Smith Age 65 First Elected to Board—2001 Occupation: Chief Executive Officer, Molecular Imprints, Inc.		Dr. Melliar-Smith is the Chief Executive Officer of Molecular Imprints, Inc., a high resolution nanoimprint lithography manufacturing solutions business based in Austin, Texas, since 2005. From March 2003 to September 2005 he was Chief Operating Officer of Molecular Imprints, Inc. From January 2002 to October 2003, Dr. Melliar-Smith was a Venture Partner with Austin Ventures, a venture capital firm focusing on telecommunications, semiconductor and software businesses. From January 1997 to December 2001, Dr. Melliar-Smith was the President and Chief Executive Officer of International SEMATECH, a research and development consortium for the integrated circuit industry. He received his B.S. and Ph.D. in chemistry from Southampton University in England and his M.B.A. from Rockhurst College. Dr. Melliar-Smith also has served since 2001 as a director of Technitrol, Inc., which changed its name to Pulse Electronics Corp. (NYSE:PULS) in November 2010. 2010 Committees: Nominating and Corporate Governance Committee, Chairman                                Audit Committee         Qualifications: Dr. Melliar-Smith has more than 35 years of experience in high technology companies involved in research and development, manufacturing and business unit management. His leadership roles in these companies brings to the Board a strong background in managing issues unique to technology businesses. Dr. Melliar-Smith is also experienced with venture capital and has been involved with several start-up companies, which brings valuable insight to the Board with respect to financing activities.

11

---

Table of Contents

Richard M. Swanson Age 65 First Elected to Board—2010 Occupation: Founder and President Emeritus of SunPower Corporation		Dr. Swanson was appointed to the Board of Directors on October 29, 2010. He is the founder of SunPower Corporation, a provider of solar cells, panels, inverters and imaging detectors, and served as its President and Chief Technology Officer from 1992 until May 2010, when he became President Emeritus. Dr. Swanson received his Ph.D. in Electrical Engineering from Stanford University in 1974. In 1976, he joined the faculty at Stanford University where he and his group conceived and developed the point-contact solar cell. In 1991, Dr. Swanson resigned from his faculty position to devote himself full time to SunPower Corporation.         Qualifications: Dr. Swanson's significant experience in the field of solar technology provides unique insight to the Board regarding the Company's renewable energy business, and renewable energy markets, products and regulations, as well as issues unique to the renewable energy sector. His background in electrical engineering provides skills and knowledge directly related to the Company's power business as well. Dr. Swanson's leadership role at SunPower Corporation, and his success in founding and growing the business, provide unique insight and direction to the Company's senior management team.
Jay Walters Age 63 First Elected to Board—2000 Chairman of the Board Occupation: Owner and Executive of Magnolia Enterprises		Mr. Walters has served on the Board of Directors since 2000 and as Chairman of the Board of Directors since June 2007. Since 2007, Mr. Walters has been an owner and executive of Magnolia Enterprises, a company that restores and manages properties along the Gulf Coast. From March 2000 to June 2007, Mr. Walters was President of New Horizon Services, LLC, a technology consulting company. Prior to joining New Horizon Services, Mr. Walters held several executive positions with Lucent Technologies, Inc. until his retirement in 1999. Mr. Walters received his B.S. in nuclear engineering from the University of Wisconsin and his M.B.A. from Louisiana State University.         Qualifications: Mr. Walters' significant experience in leadership positions with technology companies provides insight to the Board on global and other issues unique to technology businesses.

Non-Independent Common Stock Director Nominee

Richard J. Thompson Age 61 First Elected to Board—2007 Occupation: Chief Executive Officer and President of Power-One, Inc.		Mr. Thompson has served on the Board of Directors of Power-One, Inc. since 2007. He was appointed to serve as the Company's Chief Executive Officer in February 2008 and assumed responsibility as its President as well in September 2008. From May 2005 until March 2007, Mr. Thompson served as Senior Vice President, Finance and Chief Financial Officer of American Power Conversion Corporation (acquired by Schneider Electric in February 2007) and before that he served as Chief Financial Officer, Secretary and Treasurer of Artesyn Technologies for fifteen years. Mr. Thompson earned his B.B.A. from Lamar University in Beaumont, Texas.         Qualifications: Mr. Thompson's role as Power-One's President and Chief Executive Officer provides the Board with a channel for obtaining detailed and specific information about the Company and its operations. Mr. Thompson has demonstrated vision and leadership that returned the Company to profitability in the fourth quarter of fiscal 2009. His significant related business and financial expertise add further value to the Board.

12

---

Table of Contents

        Although our Preferred Stock Directors are not elected by the holders of our Common Stock, we believe they possess qualifications and experience that add significant value to our Board of Directors.

Non-Independent Preferred Stock Directors

Kyle Ryland Age 45 First Elected to Board—2009 Occupation: Managing Director of Silver Lake Sumeru		Mr. Ryland joined the Power-One Board of Directors in May 2009 upon the closing of the transactions contemplated by the Securities Purchase Agreement dated April 23, 2009 between the Company and Silver Lake Sumeru Fund L.P. and Silver Lake Technology Investors Sumeru L.P., discussed in detail in the Company's Form 10-K filed on March 17, 2010. Mr. Ryland was re-elected to the Board by the Preferred Stockholders at the 2010 Annual Meeting of Stockholders. Mr. Ryland is a Managing Director of Silver Lake Sumeru, an investment company focused on middle market strategy. He joined Silver Lake Sumeru in 2007 from Shah Capital Partners, an investment company focused on technology companies. Mr. Ryland has in-depth experience with investments, financings and mergers and acquisitions in the technology sector. Before joining Shah Capital, Mr. Ryland was a managing director at Lehman Brothers, where he was the head of Global Technology Investment Banking. Prior to joining Lehman Brothers, he was an investment banker at Robertson Stephens, where he also worked in the venture capital group executing venture capital and leveraged buyout transactions in the technology industry. He holds a B.A. in Political Science and Public Policy Studies from Duke University and an M.B.A. from the Wharton School of Business.         Qualifications: Mr. Ryland's significant experience with investing in technology businesses provides unique insight to the Board on the global trends and performance of similarly situated companies.
Ajay Shah Age 51 First Elected to Board—2009 Occupation: Managing Director of Silver Lake Sumeru		Mr. Shah joined the Power-One Board of Directors in May 2009 upon the closing of the transactions contemplated by the Securities Purchase Agreement dated April 23, 2009 between the Company and Silver Lake Sumeru Fund L.P. and Silver Lake Technology Investors Sumeru L.P., discussed in detail in the Company's Form 10-K filed on March 17, 2010. Mr. Shah was re-elected by the Preferred Stockholders at the 2010 Annual Meeting of Stockholders. Mr. Shah joined Silver Lake in 2007 as a Managing Director and founded the firm's middle market strategy, Silver Lake Sumeru. Prior to joining Silver Lake, Mr. Shah founded Shah Capital Partners in 2004, and prior to that he founded and managed the Technology Solutions Business of Solectron. Mr. Shah was the CEO of Smart Modular Technologies, a company he co-founded in 1989 and led through its public offering in 1995. Mr. Shah serves on the Board of Smart Modular Technologies (NASDAQ: SMOD) and is its Chairman. Mr. Shah served on the board of Flextronics International Ltd. (NASDAQ: FLEX) from 2005 to 2009. He has a B.S. in Engineering from the University of Baroda and an M.S. in Engineering Management from Stanford University.         Qualifications: Mr. Shah's experience with founding and successfully leading technology businesses, and with investing in technology businesses provides a unique perspective to the Board regarding the Company.

        In an uncontested election, such as the current election, for a Common Stock Director to be elected to the Board, he/she must receive a majority of the votes cast at the Annual Meeting by

13

Table of Contents

stockholders entitled to vote thereon, subject to the Company's Majority Voting policy. Under the Company's Majority Voting Policy, for a Common Stock Director nominee to be eligible for nomination for election or re-election to the Board, whether in a contested or uncontested election, the nominee must deliver to the Board an irrevocable resignation letter conditioned upon such nominee's failure to receive, in an uncontested election, a greater number of votes cast in favor of such nominee's election than the number of votes withheld from such nominee's election ("Majority Vote") and to resign upon the acceptance of such resignation by the Board. Upon receipt of a tender of resignation, the Nominating and Corporate Governance Committee will promptly consider the resignation, considering all relevant factors concerning the director, including but not limited to: (i) the stated reasons, if any, why votes were withheld and whether the underlying issue has been or can be cured, (ii) the nominee's length of service, (iii) the nominee's qualifications and contributions, (iv) compliance with exchange listing standards for Board composition, including independence and financial expertise, (v) whether accepting the resignation would trigger a payment under an employment agreement or a "change of control" under a credit or other agreement, and (vi) the best interests of the Corporation and its stockholders, and thereafter make a recommendation to the Board regarding whether the resignation should be accepted. The Board will then act on the Nominating and Corporate Governance Committee's recommendations at its first regularly scheduled meeting following certification of the stockholder vote, but in any case, no later than 90 days following the certification of the stockholder vote. In considering the Nominating and Corporate Governance Committee's recommendation, the Board will consider the above-mentioned factors and any additional information and factors the Board deems relevant. The Company will publicly disclose its decision with respect to any resignation in a periodic or current report it files with the SEC.

        Any broker-non votes with respect to the election of one or more directors will not be counted as a vote cast and, therefore, will have no effect on the vote.

        Each of the two Preferred Stock Director nominees are elected by the holders of Preferred Stock, which are both affiliates of Silver Lake Sumeru.

RECOMMENDATION

        THE BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT THE COMMON STOCKHOLDERS VOTE "FOR" THE ELECTION OF ALL OF THE COMMON STOCK DIRECTORS NAMED HEREIN.

14

Table of Contents

CORPORATE GOVERNANCE

        Power-One's Board of Directors and its executive officers are committed to operating the Company in accordance with established governance principles and sound business practices. This framework provides the fundamental foundation from which the Company's management team pursues long-term strategic objectives aligned with the interests of the Company's stockholders.

Board Composition and Independence

        In accordance with the governance guidelines established by NASDAQ, the Board believes that a majority of its members are independent directors under the NASDAQ Listing Standards. Each year, the Nominating and Corporate Governance Committee reviews the qualifications and independence of each Common Stock Board member and any proposed nominees for Board membership prior to making recommendations to the Board regarding proposed Common Stock Director nominees to serve as directors for the next year. In doing so, the Nominating and Corporate Governance Committee takes into account all relevant facts, circumstances and affiliations, direct or indirect, relationships, and related person transactions that might impact a member's independence from the Company and its management. The Nominating and Corporate Governance Committee has determined that the following directors are independent under the NASDAQ Listing Standards: Messrs. Kendall Bishop, Jon Gacek, Kambiz Hooshmand, Richard Swanson, Jay Walters and Dr. Mark Melliar-Smith. Accordingly, all of the Director nominees for election to the Board of Directors are independent, except Mr. Thompson due to his current service as an executive of the Company, and Messrs. Ryland and Shah, due to their affiliation with the Company's preferred stockholder.

        The Company believes that the composition of its Board represents a diverse range of industry, financial, operational and professional experience. In addition, in an effort to strengthen the effectiveness of the Board and ensure that its members keep abreast of governance and oversight trends and other issues of interest to directors of publicly traded companies, the Company encourages its directors to participate in continuing education programs. The Company purchases memberships in the National Association of Corporate Directors for all members of the Board and encourages their attendance at director continuing education programs. The Company reimburses the reasonable expenses of continuing Board education courses for its Board members.

        The Company's Governance Guidelines state that directors may not stand for re-election after reaching age 75. The Company also requires its directors to offer their resignation whenever their principal employment changes. The Nominating and Corporate Governance Committee then evaluates the director's changed circumstance and its potential impact on the Board member's ability to continue to effectively contribute to the Board's performance of its functions. The Nominating and Corporate Governance Committee makes a recommendation to the Board on whether the member should continue to serve, but the final decision is made by the Board after taking into account the Committee's recommendation. Board members are also required to submit their resignation if they fail to receive a majority of the votes cast in an uncontested election of directors.

Board Responsibilities

        Members of the Company's Board are expected to devote sufficient time and attention to their duties and responsibilities and to ensure that their other responsibilities, including service on other boards, do not interfere with their responsibilities to Power-One. Directors are expected to prepare for and attend all Board meetings and meetings of Committees to which they are assigned absent extenuating circumstances. It is also the Company's policy that Board members attend the Annual Meeting of Stockholders if possible. Regular Board meetings are scheduled quarterly. Special meetings are called whenever necessary or appropriate. Last year, the Board held four quarterly meetings and ten special meetings. Each director attended at least 75% of the Board meetings and meetings of

15

Table of Contents

Committees on which he served in fiscal 2010. All of our then current directors attended the 2010 Annual Meeting of Stockholders or participated telephonically.

        Executive sessions with independent directors typically occur during the regular quarterly meetings of the Board and at any other time that the Board, in its discretion, believes necessary or appropriate. Executive sessions are chaired by Jay Walters, the Chairman of the Board or by his designee. Mr. Walters qualifies as an independent director under the NASDAQ Listing Standards and the Sarbanes-Oxley Act of 2002.

        The Board, and each Committee, is authorized to engage independent outside financial, legal and other consultants as they deem necessary or appropriate. Directors also have full access to members of the Company's management team.

Board Structure

        Currently the roles of Chief Executive Officer and Chairman of the Company are separate, with Mr. Thompson serving as the Chief Executive Officer and Mr. Walters serving as Chairman. The Board has determined that having an independent director serve as Chairman is in the best interests of the Company at this time. It allows the Chief Executive Officer to focus on the strategic direction of the Company and managing the Company's business while the Chairman focuses on Board matters and provides independent oversight and advice to management. Because our Chief Executive Officer does not also serve as the Chairman of the Board, we do not currently have a separate Lead Director. As discussed above, however, the Company's independent directors regularly meet in executive sessions under the leadership of Mr. Walters.

Risk Management and Oversight

        Our full Board of Directors oversees the Company's risk management process. Our Board oversees a Company-wide approach to risk management, carried out by management. Our full Board determines the appropriate risk for the Company generally, assesses the specific risks faced by the Company and reviews the steps taken by management to manage and mitigate those risks.

        While the full Board maintains the ultimate oversight responsibility for the risk management process, its committees oversee risk in certain specified areas. In particular, our Compensation Committee is responsible for overseeing the management of risks relating to the Company's executive compensation plans and arrangements and the incentives created by the compensation awards it administers. Our Audit Committee oversees management of enterprise risks as well as financial risks and potential conflicts of interests. Our Nominating and Corporate Governance Committee is responsible for overseeing the management of risks associated with the independence of the Board of Directors. Pursuant to the Board's instruction, management regularly reports on applicable risks to the relevant committee or the full Board, as appropriate, with additional review or reporting on risks conducted as needed or as requested by the Board and its committees.

Evaluation of Nominees

        The Nominating and Corporate Governance Committee identifies potential candidates for Board membership as Common Stock Directors through professional search firms and/or personal referrals. Candidates for Board membership as Preferred Stock Directors are identified by the holders of the outstanding Preferred Stock. Candidacy for Board membership requires a determination that the candidate, whether for a position as a Common Stock Director or a Preferred Stock Director, meets the qualifications for Board membership. The final approval of the full Board is required for candidacy as a director. Each year, the Board proposes a slate of nominees for positions as Common Stock Directors to the stockholders, who elect the Common Stock Directors at the Annual Meeting of Stockholders. Stockholders may also propose nominees for candidacy as Common Stock Directors for

16

Table of Contents

consideration by the Nominating and Corporate Governance Committee by submitting the names and supporting information regarding proposed candidates to the Corporate Secretary in accordance with the procedure set forth in the Company's Bylaws. See Section 3.13 of the Company's Bylaws and the section entitled "Information About the Annual Meeting and Voting—Stockholder Nomination of a Common Stock Director" in this proxy statement for a description of the information and timing requirements for submitting a nominee to the Company's Corporate Secretary. Candidates selected for nomination to serve as a Common Stock Director and nominees selected to serve as Preferred Stock Directors are expected to demonstrate the highest standards of personal and professional ethics, integrity and values, as well as a commitment to representing the long-term interests of the Company's stockholders. Common Stock Directors are further expected to comply with the requirements of the majority voting policy adopted by the Board of Directors.

        Candidates (including those proposed by our stockholders) are evaluated by the Nominating and Corporate Governance Committee through recommendations, resumes, personal interviews, reference checks and other information deemed appropriate by the Committee.

Stockholder Communications with the Board of Directors

        Stockholders may communicate directly with the Company's Board of Directors or with individual directors by writing to:

Board of Directors
Power-One, Inc.
740 Calle Plano
Camarillo, CA 93012

        A record of all stockholder communications is recorded by the Corporate Secretary, who then reviews the communication. Communications appropriate for Board consideration are promptly forwarded to the Chairman of the Board or the individual director or directors, as applicable. Communications that relate to general surveys, solicitations of business, advertisements, unsolicited resumes, product inquiries or complaints, sales or other communications that are unrelated to the role and responsibilities of the Board are not considered appropriate for action by the Board and are not forwarded. Communications regarding the recommendation of a director nominee are sent to the Chairman of the Nominating and Corporate Governance Committee. Communications regarding accounting or internal controls are sent to the Audit Committee Chairman's attention. The director to whom the communication is forwarded will present the communication to the full Board for discussion at the next regularly scheduled meeting of the Board (or sooner if deemed appropriate by the director) and will make recommendations if appropriate.

STANDING COMMITTEES OF THE BOARD

        The Board of Directors has established three standing committees: the Audit Committee, the Compensation Committee and the Nominating and Corporate Governance Committee. Each Committee has adopted a Charter that sets forth the Committee's role and responsibilities. The Charters can be found in the "Investor Relations" link in the "Corporate Governance" section of the Company's website at www.power-one.com. The information on our website is not incorporated by reference into this proxy statement.

Audit Committee

        Power-One's management is responsible for the Company's financial reporting process, including its system of internal controls, and for the preparation of consolidated financial statements in accordance with generally accepted accounting principles ("GAAP"). The Company's independent registered public accounting firm is responsible for auditing the financial statements prepared by

17

Table of Contents

management and confirming that they are in compliance with GAAP and with Section 404 of the Sarbanes Oxley Act of 2002 and applicable rules and regulations of the Exchange Act. The Audit Committee of the Board of Directors is responsible for monitoring the integrity of these processes and the independence and performance of the independent registered public accounting firm. The Committee also appoints the independent registered public accounting firm.

        None of the Audit Committee members are currently engaged in the practice of public accounting or auditing and they rely upon the information provided to them, and upon the representations made by management and the independent registered public accounting firm, in performing their responsibilities. The Audit Committee is authorized to retain independent experts to advise and consult directly with them if they believe an independent opinion or review of any information provided to them or representations made to them by management or the independent registered public accounting firm is necessary or appropriate.

18

Table of Contents

Compensation Committee

19

Table of Contents

20

Table of Contents

Nominating and Corporate Governance Committee

21

Table of Contents

Compensation of Directors

Compensation Program for Independent Common Stock Directors

        For fiscal 2010, the annual compensation program for Independent Common Stock Directors included both a cash component and an equity component. The compensation program was approved by the Board in February 2010, based on the recommendation of the Compensation Committee following a review of the directors' compensation by the Compensation Committee's independent consultant, Compensia, who was hired in the fourth quarter of fiscal 2009 to provide advice to the Committee on various compensation issues throughout 2010, including making recommendations with respect to compensation. Compensia was requested to review the compensation of the independent Common Stock Directors in light of market practices and recent trends and developments and to present a summary of its findings and preliminary observations, along with a detailed analysis of the compensation programs of the Company's Peer Companies(1) to the Compensation Committee. Following its review of the Independent Common Stock Directors' compensation program, Compensia recommended a retainer-based structure competitive with the market median for comparable companies and further recommended that individual meeting fees be discontinued, except as needed to compensate for extraordinary circumstances requiring unusual time commitments.

(1)

Peer companies used for analysis by Compensia Inc., were Advanced Energy Industries American Superconductor, Broadwind Energy, Energy Conversion Devices, EnerNOC, ESCO Technologies, Evergreen Solar, Fuel Systems Solutions, FuelCell Energy, GT Solar, Maxwell, Powell Industries, SunPower, Technitrol

22

Table of Contents

        The following table sets forth the retainer based compensation structure adopted by the Board of Directors on February 16, 2010.

        We believe a significant portion of our directors' compensation should be in the form of equity to align their interests with those of our stockholders. Following its review of our Independent Common Stock Director compensation program, Compensia recommended that the Board shift to a "target grant value approach" for awarding equity, which is used by a majority of the Peer Companies. Under this approach, each year the Independent Common Stock Directors receive a grant of Restricted Stock Units, the number of shares subject to which is determined by dividing the target grant value by the 10-day average stock price immediately prior to the grant date. In February 2010, the Board approved the following target grant value amounts for the initial and annual equity awards to the Independent Common Stock Directors.

(1)

The annual retainer is intended to provide fair compensation for an anticipated number of meetings, after which a per meeting fee may be paid at the discretion of the Chairman of the Board or the Chairman of the applicable committee. Directors may also receive additional compensation for service on special committees created by the Board from time-to-time to address specific issues. The Company also reimburses non-employee directors for reasonable out-of-pocket expenses incurred in connection with attending Board and Committee meetings and meetings of the National Association of Corporate Directors. None of the Independent Common Stock Directors receive any other compensation from the Company for their services as directors. Prior to February 2010, in addition to an annual retainer, Independent Common Stock Directors received meeting fees in the amount of $3,000 per day for in person meetings and $1,000 per day for telephonic meetings that exceeded two hours and involved substantial time and preparation.

(2)

In addition to annual grant.

        The Independent Common Stock Directors are eligible for an annual award if they have served on the Board at least 180 days prior to the date of the Annual Meeting of Stockholders. Annual equity awards vest on the earlier to occur of (i) the first anniversary of the grant or (ii) one day before the next Annual Meeting of Stockholder. Grants made to the Independent Common Stock Directors upon their initial election or appointment to the Board vest in equal installments over a period of three years on the first to occur in each year of (i) the anniversary of the grant or (ii) one day before the Annual Meeting of Stockholder's. Awards available under the target grant value approach are capped at 37,500 shares for annual grants to Board members other than the Chairman of the Board, at 50,000 shares for annual grants to the Chairman of the Board and at 62,500 shares for initial grants to new Board members.

        Upon election to the Board of Directors at the Annual Meeting of Stockholders held on May 24, 2010, each Independent Common Stock Director other than the Chairman of the Board received an annual equity grant valued at $75,000. The average per share price based upon on the 10 day average

23

Table of Contents

price of the Company's Common Stock leading up to the grant date was $7.52, which translated into awards of 9,973 shares for Messrs. Bishop, Gacek, and Hooshmand, and Dr. Melliar-Smith. Mr. Walters received an annual equity grant valued at $95,000 due to his service as Chairman of the Board, which, at an average price of $7.52 per share translated to an award of 12,633 shares. Upon election to the Board in October 2010, Dr. Swanson received an initial grant valued at $125,000, which at $10.59 per share translated into an award of 11,797 shares.

Stock Ownership Guidelines

        In July 2008 the Company established stock ownership guidelines for directors, which guidelines were amended in February 2010 to increase the value of Common Stock required to be held by the Independent Common Stock Directors from $100,000 to three times the value of the stock component of a director's annual compensation, or $225,000 under the current compensation plan for all Independent Common Stock Directors except the Chairman of the Board, who is required to own stock valued at $300,000. Directors have five years after the later of February 2010 or the date upon which a director is appointed to the Board to satisfy these stock ownership guidelines. As of January 2011, each of the Independent Common Stock Directors either already met his stock ownership target or was on track to meet his stock ownership target within the required timeframe.

Other Compensation, Plans or Benefits

        The Company does not provide the Independent Common Stock Directors with any other compensation, benefits, compensation deferral arrangements, perquisites, severance, or other consideration for service to the Company as a director. All directors are entitled to participate in the medical benefit programs offered to the Company's employees; however, at his own expense. The following table presents information regarding the compensation paid to each of our Independent Common Stock Directors for fiscal 2010. Non-Independent Common Stock Directors and Preferred Stock Directors do not receive any compensation in cash or equity for their service to the Board. Thus, Messrs. Thompson, Ryland or Shah did not receive any compensation for their service to the Board in fiscal 2010.

DIRECTOR COMPENSATION 2010

24

Table of Contents

        The following table presents the number of outstanding and unexercised option awards and the number of unvested stock awards held by each Independent Common Stock Director as of January 2, 2011.

PROPOSAL TWO

ADVISORY RESOLUTION ON NAMED EXECUTIVE OFFICER COMPENSATION

        The recently enacted Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010 (the "Dodd-Frank Act") enables the Company's stockholders to vote on an advisory (non-binding) basis regarding the compensation of the Company's executives, as disclosed in this proxy statement in accordance with the SEC's rules (commonly referred to as a "say on pay" vote). The Company is asking its stockholders to approve an advisory resolution on the compensation of the Company's Named Executive Officers as reported in this proxy statement. While this vote is non-binding, the Compensation Committee of the Board values the opinions of the Company's stockholders and to the extent there is any significant vote against the compensation of the Named Executive Officers as disclosed in this proxy statement, the Committee will take into account stockholders' concerns and will evaluate whether any actions are necessary to address those concerns.

25

Table of Contents

        The Compensation Committee has structured the Company's executive compensation program to achieve the following key objectives:

        As discussed in the Compensation Discussion and Analysis beginning on page 28 of this proxy statement, the Board believes that our current executive compensation program directly links executive compensation to our performance and aligns the interests of our executives with those of our stockholders. We urge our stockholders to read the "Compensation Discussion and Analysis" which describes in more detail how our executive compensation policies and procedures operate and are designed to achieve our compensation objectives, as well as the Summary Compensation Table and other related compensation tables and narratives, appearing on pages 39 through 48, which provide detailed information on the compensation of our Named Executive Officers. The Compensation Committee and the Board of Directors believes that the policies and practices discussed in the "Compensation Discussion and Analysis" are effective in achieving our goals and that the compensation of our Named Executive Officers reported in this proxy statement has contributed to the Company's recent and long-term success.

        In accordance with recently adopted Section 14A of the Exchange Act, and as a matter of good corporate governance, the Board of Directors asks the Company's stockholders to vote "FOR" the following resolution at the 2011 Annual Meeting of Stockholders:

"RESOLVED, that the stockholders of the Company approve, on an advisory basis, the compensation of the Company's Named Executive Officers as disclosed pursuant to Item 402 of Regulation S-K, including the Compensation Discussion and Analysis, the Summary Compensation Table, and the related compensation tables, notes and narrative in the proxy statement for the Company's 2011 Annual Meeting of Stockholders."

        The approval of the advisory resolution of the compensation of the Named Executive Officers requires the approval of a majority of the voting power of the shares of Common Stock and Preferred

26

Table of Contents

Stock, voting together as a single class, represented at the Annual Meeting and eligible to vote thereon. For purposes of this proposal, abstentions will have the same effect as a negative vote, while broker non-votes will not be counted as a vote cast and, therefore, will have no effect on the vote.

RECOMMENDATION

        THE BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS A VOTE "FOR" THE APPROVAL OF THE ADVISORY RESOLUTION ON THE COMPENSATION OF THE NAMED EXECUTIVE OFFICERS.

PROPOSAL THREE

ADVISORY VOTE ON THE FREQUENCY OF FUTURE ADVISORY
VOTES ON NAMED EXECUTIVE OFFICER COMPENSATION

        Pursuant to recently adopted Dodd-Frank Act, the Board is asking the Company's stockholders to vote on whether future advisory votes on the compensation of the Named Executive Officers in the nature of a proposal similar to that reflected in Proposal Number Two above, should occur every year, every two years or every three years.

        After careful consideration, the Board has determined that holding an advisory vote on the compensation of the Named Executive Officers every two years is the most appropriate policy for the Company, and recommends that the Company's stockholders vote for future advisory votes on the compensation of the Named Executive Officers every two years. The Company's executive compensation program is designed to promote a long-term connection between pay and performance and although executive compensation disclosures are made annually, holding a biennial advisory vote on Named Executive Officer compensation serves the dual purpose of providing our stockholders with recent and timely compensation disclosures while providing sufficient time for management to demonstrate a performance trend and for the stockholders to evaluate the Company's overall compensation strategy, design, philosophy and implementation in light of management's performance. A two year period is aligned with the longer-term view that the Compensation Committee takes with respect to significant components of our executive compensation program and also provides stockholders with a sufficient opportunity to evaluate the effectiveness of our compensation program over a period long enough to evaluate performance.

        Stockholders are advised that because the advisory vote on the compensation of the Named Executive Officers occurs well after the beginning of the compensation year, it may not be appropriate or feasible to change our executive compensation program in consideration of an annual advisory vote on Named Executive Officer compensation. We nevertheless believe that a biennial advisory vote on the compensation of the Named Executive Officers is consistent with our practice of respecting the opinions of our stockholders on governance matters, including the Company's practice of having all directors elected annually by our Common Stock and Preferred Stock stockholders and annually providing our stockholders with an opportunity to ratify the Audit Committee's selection of independent auditors.

        This advisory vote on the frequency of future advisory votes on the compensation of Named Executive Officers compensation is non-binding on the Board and the Compensation Committee. Stockholders will be able to specify one of four choices for this proposal on the proxy card: (i) one year, (ii) two years, (iii) three years or (iv) abstain. Although non-binding, the Board and the Compensation Committee will carefully review the voting results. Notwithstanding the Board's recommendation and the outcome of the stockholders votes, the Board may in the future decide to conduct advisory votes on a more or less frequent basis and may vary its practice based on factors such as discussions with stockholders and the adoption of material changes to existing compensation programs.

27

Table of Contents

        The advisory recommendation on the frequency of future advisory votes on executive compensation requires the approval of a majority of the voting power of the shares of Common Stock and Preferred Stock, voting together as a single class, represented at the Annual Meeting and eligible to vote on thereon. Stockholders may vote in favor of holding future executive compensation advisory votes every year, every two years or every three years, or may choose to abstain. For purposes of this proposal, abstentions will have the same effect as no vote, and broker non-votes will not be counted as a vote cast and, therefore, will have no effect on the vote.

RECOMMENDATION

        THE BOARD OF DIRECTORS RECOMMENDS STOCKHOLDERS VOTE "FOR EVERY TWO YEARS" TO CONDUCT FUTURE ADVISORY VOTES ON THE COMPENSATION OF THE NAMED EXECUTIVE OFFICERS

COMPENSATION DISCUSSION AND ANALYSIS

Overview

        The Compensation Committee of the Board of Directors (the "Committee") is responsible for overseeing the compensation of the Company's Chief Executive Officer (the "CEO"), the Chief Financial Officer and the executives who directly report to the CEO (including all of the other Named Executive Officers) and for ensuring that the Company's compensation program meets the objectives of attracting, retaining, motivating and fairly compensating the Company's senior executives and closely aligning their interests with those of the Company's stockholders.

        This Compensation Discussion and Analysis, is designed to assist the Company's stockholders in understanding the objectives of our compensation strategy for our named executive officers whose compensation is reported in this year's proxy statement ("Named Executive Officers") and to fully describe the various components of the compensation paid to or earned by our Named Executive Officers in fiscal 2010, as well as the basis for the Committee's decisions regarding such compensation. The Named Executive Officers for fiscal 2010 were:

•

Richard Thompson, President and CEO;



•

Gary Larsen, Senior Vice President, Finance, and Chief Financial Officer (the "CFO") from August 16, 2010 to present;



•

Linda Heller, former Senior Vice President, Finance, and Chief Financial Officer (the "former CFO") from January 3, 2010 until August 13, 2010;



•

Alex Levran, President, Renewable Energy Solutions (the "President RES");



•

Neil Dial, Senior Vice President, Operations (the "SVP Operations"); and



•

Tina McKnight, General Counsel and Secretary (the "GC").

Executive Compensation Program Philosophies and Objectives

        The Committee believes that bonuses, incentive payments and other performance based awards must be linked to measurable performance metrics associated with key financial and operational benchmarks and that incentive compensation should reflect the scope of an individual's responsibilities, his or her ability to impact the Company's performance and actual contribution to the Company's success. The Committee also believes that equity should represent a meaningful portion of an executive's total compensation in order to closely align their interests with the interests of the Company's stockholders and to ensure that stockholder value remains a primary objective for the executives. The Committee also strives to balance current results with future expectations and believes

28

Table of Contents

that in certain circumstances, it may be appropriate to award a salary increase, discretionary bonus or other form of compensation as a reward for outstanding performance by an individual and as an effective tool for retaining key executives responsible for the performance of mission critical tasks that may not necessarily result in immediate financial performance improvement for the Company.

        Market competitiveness and equitable principles are central elements of the Committee's compensation policies. The aggregate compensation of each Named Executive Officer is evaluated by comparison to that of executives at similar companies in related industries who hold the same positions or have substantially similar levels of responsibility, as well as by comparison to other executives within the Company who have comparable levels of responsibility. Such an analysis was undertaken with the assistance of Compensia in late 2009 for consideration with respect to the 2010 compensation of the Named Executive Officers. Compensia was asked to review the Company's total target cash compensation, including non-equity incentives, and its long-term incentives to determine whether target total direct compensation was competitive in light of the Company's performance against its peers. The Compensation Committee worked with Compensia to develop a peer group for purposes of understanding market competitive pay levels and practices. In selecting peer companies, the Company/Compensia targeted U.S.-based publicly-traded companies that were generally within 0.5x to 2.0x Power-One's revenues and number of employees and within 0.33x to 3.0x Power-One's market capitalization. At the time the Peer Companies were selected, Power-One's trailing-twelve month revenues and fiscal year end number of employees were both above the median of the peer group whereas Power-One's market capitalization was below the median of the Peer Group. The peer companies used for the analysis are as follows: Advanced Energy Industries American Superconductor, Broadwind Energy, Energy Conversion Devices, EnerNOC, ESCO Technologies, Evergreen Solar, Fuel Systems Solutions, FuelCell Energy, GT Solar, Maxwell, Powell Industries, SunPower, and Technitrol and represent the same Peer Companies used to review the compensation of the Board. In addition to retaining the services of a compensation consultant, from time-to-time the Committee may review publicly disclosed compensation information of the named executive officers of other companies in related industries within comparative geographical regions and of companies with whom we compete with for executives.

        The Committee also places significant weight upon an individual executive's role within the Company, his or her leadership responsibilities, performance during the last year, his or her ability to impact the overall performance of the Company and his or her contribution to the Company's recent performance in making compensation decisions.

        The Committee's compensation objectives include:

•

providing a competitive total compensation package that enables the Company to attract and retain key executives with the requisite skills, experience and vision to manage our business;



•

motivating achievement of annual target performance goals by providing short-term compensation opportunities linked to performance;



•

providing long-term compensation incentives, primarily through equity awards, that align executive compensation with the interests of the Company's stockholders; and



•

promoting ownership of the Company's stock by its executives to further align the interests of executives with those of the Company's stockholders. In February 2010, the Company adopted the following stock ownership guidelines for the CEO and his direct reports (including all of the other Named Executive Officers).

29

Table of Contents

For purposes of monitoring compliance with the guidelines, the Committee uses the higher of (i) the market price of the Company's Common Stock at the close of trading on the date of acquisition or vesting or (ii) the market price of the Company's Common Stock at the close of trading on the first trading day of the Company's fiscal year. Vested stock options owned by executives are counted toward their stock ownership requirement and are calculated at the in-the-money value of the option on the date of valuation.

Once an executive achieves the applicable target level of stock ownership, he or she will remain in compliance with the stock ownership guidelines if the executive does not sell stock or initiate a cashless exercise of options. Sales of stock and cashless exercises of options are deducted from the stock ownership valuation. As of January 2011, each of the Named Executive Officers either already met his or her stock ownership target or was on track to meet his or her stock ownership target within the required time frame.

Establishing Executive Compensation

        The ultimate decision making authority and final approval of the compensation packages for the Named Executive Officers resides with the Compensation Committee. The Compensation Committee evaluates the CEO's compensation annually in light of his performance against pre-established performance objectives set for the Company and any individual performance objectives assigned to the CEO from time-to-time. In 2010, the performance of all of the Named Executive Officers was measured against the corporate objectives discussed below in "Short-Term Incentives—Cash Bonus Plan". The Committee determined that due to the transformational nature of the business in 2010, it was in the best interests of the Company and its stockholders for all of the Named Executive Officers to share common goals and to remain focused on a unified roadmap for the near future. For that reason, in 2010 all of the Named Executive Officers were measured against financial goals set for the Company at the beginning of fiscal 2010. The goals set for the Company and for all of the Named Executive Officers focused on revenue, adjusted EBITDA, and cash from operations.

        The Committee has the sole authority to set the CEO's compensation based on its evaluation of the CEO's performance and upon its review of the CEO's compensation relative to the other Named Executive Officers and to the compensation of the CEO's of the Peer Companies. Annually, the CEO evaluates the performance of his direct reports, which includes all of the other Named Executive Officers against the corporate objectives set for the Company at the beginning of the year and, if applicable, against personal objectives set for each individual Named Executive Officer by the CEO. In 2010, personal objectives were not set for the Named Executive Officers. Based upon his evaluation of each Named Executive Officer, the CEO makes compensation recommendations for each Named Executive Officer to the Committee for its review and approval. The Committee determines for the CEO and, after consideration of the CEO's recommendations for the other Named Executive Officers, established the aggregate compensation opportunities available for that fiscal year, based upon a number of factors, including the executive's position, experience and performance (particularly over the past year, if applicable), as well as competitive market data, if available, and retention concerns.

Elements of Executive Compensation

        The Committee's objectives are implemented through the Company's executive compensation program, which is comprised of three primary elements: base salary, annual incentive compensation and long-term incentive compensation. The table below lists each material element of executive compensation, the objective(s) that it is designed to achieve, and the characteristics of each compensation element.

30

Table of Contents

Key Elements of Compensation

31

Table of Contents

        Secondary elements of executive compensation include the health and welfare benefits and perquisites discussed below that serve to attract and retain qualified executives; however, the Committee's philosophy is that a significant portion of executive compensation should not be in the form of executive benefits and perquisites. To the extent that they are provided, such elements are typically not at risk and involve costs that are generally fixed.

        The Committee believes that both annual and long-term incentive compensation should reflect the performance of the Company as well as the individual contribution of each executive and further believes that a significant portion of executive compensation should be linked to stockholder value. Accordingly, the aggregate compensation paid to each Named Executive Officer is significantly weighted toward annual and long-term incentive compensation, both of which are "at risk" if the Company does not achieve its operating goals and strategic objectives and/or are tied directly to the Company's stock price performance. At risk compensation reflects the Committee's position that executives and key employees should be paid for performance.

        The actual pay mix for our CEO and the three other Named Executive Officers who were employed by Power-One for the entire 2010 fiscal year is shown below:

1.

Other Named Executive Officers include: Alex Levran, Neil Dial and Tina McKnight.

Base Salary

        We view base salary as an important component of each Named Executive Officer's overall compensation package. We strive to provide our Named Executive Officers with base salaries that are aligned with their roles and responsibilities and that we believe to be competitive when compared to our Peer Companies. Base salaries are reviewed annually and at the time of promotion or other significant changes in responsibilities. The Committee sets the base salary of our CEO and considers the recommendations of the CEO for the base salaries of the Named Executive Officers, with a goal toward setting base salary compensation competitive with the market median of the Peer Companies and taking into account the level of responsibility, experience and tenure of the individual, and the amount of performance-based incentives received or granted each year. The Committee exercises discretion to compensate above the market median to recognize sustained exemplary performance and contribution and for certain key executives who are critical to achievement of the Company's mission. As noted below, Dr. Levran received an additional increase in 2010 in recognition of his appointment as President of the Renewable Energy Solutions business and for his contribution to the Company's success and achievement of its financial goals in 2010.

        Effective February 1, 2010, each of our Named Executives Officers received annual base salary increases as follows: Mr. Thompson received an increase of 10% to $550,000, bringing him between the median and 75^th percentile for the CEO's of the Peer Companies and rewarding him for his strong

32

Table of Contents

performance in 2009; Dr. Levran received an increase of 6% to $350,000, bringing his base salary above the 75^th percentile for his position as Chief Technology Officer; Mr. Dial received an increase of 4% to $365,000, bringing him above the 75^th percentile for the top operations executive of the Peer Companies; Ms. Heller received an increase of 4% to $260,000 which was below the 25^th percentile for Chief Financial Officers of the Peer Companies and Ms. McKnight received an increase of 8% to $270,000, which approximates market median in recognition of her contribution to the Company's overall performance in 2009 and in recognition of the additional human resources responsibilities she assumed while the position of Vice President, Human Resources was vacant. In September 2010, the Committee approved a further increase of approximately 14% for Dr. Levran in recognition of his appointment as President of the Renewable Energy Solutions business unit, bringing his base salary to $400,000, slightly above the 75^th percentile of the Peer Companies. The increase was approved in consideration of Dr. Levran's heightened leadership role as President of the Company's Renewable Energy Solutions business and his role in the Company's overall performance during the first half of 2010.

Short-term Incentives—Cash Bonus Plans

        Annual incentive compensation is a key means for implementing the Committee's philosophy that executives should be paid for performance. The Management Incentive Plan (the "MIP") is a bonus plan that rewards eligible participants, including the Named Executive Officers, for achievement of pre-established target performance objectives and individual goals. The employees most responsible for the Company's financial performance, including our Named Executive Officers, participate in the MIP. In fiscal 2010 there were approximately 38 plan participants, including each of our Named Executive Officers. The target award opportunities under the MIP for fiscal 2010 (the "2010 MIP") for the Named Executive Officers were as follows:

        Ms. Heller was not eligible to receive an annual incentive award under the 2010 MIP as she was not employed by the Company on the payout date. All MIP participants were eligible to earn a multiplier to increase the incentive payout by up to an additional 200% (for a total potential payout of 300% of the target annual incentive award opportunity) based upon the level of achievement of the pre-established fiscal 2010 performance objectives. The pre-established performance objectives for 2010 are set forth below as part of the following table. The dollar range of the potential fiscal 2010 annual incentive awards for the Named Executive Officers, including threshold, target and maximum award levels, is presented in the "Grants of Plan-Based Awards" table. All Named Executive Officers were evaluated based upon (i) revenue achievement, (ii) profitability (based on "Adjusted EBITDA", defined as EBITDA on a GAAP basis adding back the expense accrued on the 2010 MIP Plan) and (iii) cash from operations. The target performance levels under each of these criteria reflected the Company's operating plan for fiscal 2010 and were viewed as attainable in light of market conditions and industry trends, whereas the maximum performance level was viewed as a significant yet realistic challenge to management to increase revenue and operating efficiencies that impact net income.

        The following were the performance metrics, relative weighting of each metric with respect to each Named Executive Officer's annual incentive award opportunity and the performance results under the

33

Table of Contents

2010 MIP for each Named Executive Officer. The actual amounts earned by each Named Executive Officer are set forth in the Summary Compensation Table.

(1)

2010 MIP performance targets were: Threshold—$66 million Adjusted EBITDA, $435 million revenue, $40 million cash from operations; Target (and Maximum)—$83 million Adjusted EBITDA, $535 million revenue, $50 million cash from operations. Mr. Larsen's actual payout was pro-rated in light of his August 16, 2010 start date. Actual 2010 performance on all three metrics was above the maximum level.

(2)

2010 MIP targets for plan funding were determined by Adjusted EBITDA as follows: Threshold—$66 million, Target—$83 million, Maximum—$125 million. For performance between threshold and target, funding was 50% of Target, plus 3% per $1 million of Adjusted EBITDA. For performance between Target and Maximum, funding was $100% of Target, plus approximately 4.75% per $1 million of Adjusted EBITDA. Funding between Target and Maximum was subject to a reduction of 1% for each $1 million of revenue that the Power Solutions business fell below $325 million. Actual 2010 Adjusted EBITDA was above the Maximum level. Power revenue was above the $325 million level resulting in no adjustment in funding.

Long-Term Incentives—Equity Compensation

        Historically, the cash compensation of the Named Executive Officers has been supplemented with equity awards that tie their overall compensation to the performance of the Company's Common Stock. In fiscal 2010, equity awards were granted to the Named Executive Officers as summarized in the Grants of Plan Based Awards—Fiscal 2010 table on page 39. The Committee adopted a strategy in 2010 to award equity to new employees using a ratio of 25% restricted stock units and 75% stock options for each award, and reserving discretion to award grants consisting of a mix of restricted stock units and stock options to existing employees or grants of 100% restricted stock units for purposes of awarding exemplary performance and minimizing the use of remaining shares available for grant under the 2004 Plan. Unlike stock options, restricted stock units have some financial value regardless of stock price volatility and therefore fewer are typically granted in comparison to options to realize the same incentive value for an executive or key employee. The ultimate value of both types of awards are directly related to the value of the Company's Common Stock and both types of awards incent executives and key employees to achieve the Company's goals and targets. The Committee believes this strategy serves the dual function of retaining executives and rewarding them for performance, and that it also aligns the interests of the Company's executives with those of its stockholders. The Committee determines, on a discretionary basis, whether an equity award should be granted and the number of shares of Common Stock subject to the award. In 2010, the Committee also adopted a policy of granting equity awards to the Company's employees once each year at the Board meeting immediately

34

Table of Contents

following the Annual Meeting of Stockholders, but it reserved discretion to award equity at other times if appropriate and as an employment incentive for certain new hires.

Restricted Stock Units and Stock Options

        At various meetings throughout the year, the Committee considered recommendations for equity awards to the Named Executive Officers. The Committee determined that the proposed awards met the compensation objectives and strategy described under "Elements of Compensation" above and ensured the long-term retention of key employees critical to achievement of the Company's mission. In reaching its decisions, the Committee took into consideration the fact that 2010 was a transformational year for the Company in which the business grew by 143% and Power-One became the second largest manufacturer of Renewable Energy inverters worldwide. The Company returned to profitability in the fourth quarter of 2009 and continued that trend throughout 2010, creating significant improvements in gross margin and operating expense throughout the year. In particular, the Committee considered the role that the CEO and each of the Named Executive Officers played in the successful transformation of the Company. The CEO was granted three separate awards of restricted stock units in February, June and October and stock options in June in recognition of his ongoing leadership of the Company during multiple refinance activities and during restructuring efforts that resulted in significant cost reductions and that returned the Company to operational profitability. The other Named Executive Officers, except Ms. Heller who left the Company in August 2010 and Mr. Larsen who joined the Company in August 2010, were awarded restricted stock units in June and October and stock options in June. The Committee considered Dr. Levran's mission critical role in leading the success of the Renewable Energy Solutions business in 2010, as well as his role in establishing the digital power technology licensing program and setting the Company's technology and product roadmap for 2010. Mr. Dial received equity awards in recognition of his role in executing the Company's plan of reorganization with respect to its worldwide operations, which included opening two new plants in Asia and a plant in North America during 2010. Ms. McKnight was awarded equity in 2010 in recognition of her overall support of the Company during its transition, including her role in providing legal support for key transactions and business opportunities, and her responsibilities as Vice President, Human Resources while that position was vacant.

        The restricted stock unit awards and stock option grants for the Named Executive Officers are reported in the "Summary Compensation Table" and the "Grants of Plan-Based Awards" table below.

Other Benefits and Perquisites

        The Named Executive Officers either participate in or are eligible to participate in our employee benefit plans and programs on the same terms as other employees, including the Company's medical and dental insurance, term life insurance, short-term disability insurance, long-term disability insurance and paid time-off plans. As more fully described in the Summary Compensation Table on page 39, the Company provided living allowances for the CEO and SVP of Operations until August and September 2010, respectively, pursuant to the terms of their respective employment agreement and offer letter, and provided certain relocation benefits for the CFO to assist with the relocation of his family to Southern California. The temporary living expense associated with the CFO's relocation package terminated in February 2011. The Company also reimburses executives for expenses incurred in connection with their employment. Nominal automobile allowances are also provided to each of the Named Executive Officers as well as to certain other employees of the Company. The value of all benefits and perquisites provided to our Named Executive Officers is reported in the Summary Compensation Table below.

35

Table of Contents

Employment, Change in Control and Other Agreements

        The Company provides each of the Named Executive Officers and certain other key employees with severance benefits under individual change in control agreements (the "CIC Agreements"), which are triggered if the individual's employment is terminated within a certain period of time following a change in control of the Company. The form of CIC Agreements used by the Company was adopted in May 2007 and is intended to ensure that in the event of a proposed change in control, the executives and other key employees remain focused upon the pending transaction. The Board believes that providing executives and key employees with transitional compensation protection if their employment ends as a result of a change in control encourages them to act in the best interests of the Company and its stockholders by eliminating personal concerns and uncertainties the executive or employee might otherwise have. The Board believes these agreements offer a fair reward for hard work and value creation, assist in retaining executives during a time of transition and provide incentives for them to remain with the Company during periods of uncertainty.

        The potential payouts to the Named Executive Officers under the CIC agreements are presented in the Change in Control Table below. Benefits under the CIC Agreements are only available if an executive is terminated without cause following a "Change in Control", as defined by the agreements, or if the executive terminates his or her employment for "Good Reason", as defined in the CIC Agreements, following a change in control of the Company.

        In addition, upon a change in control, all outstanding equity-based awards for Named Executive Officers and other key employees with CIC agreements who have received equity awards generally accelerate whether or not employment terminates. The Board believes it is appropriate to fully vest equity awards in change in control situations to allow the equity award holder to benefit from any gain in the stock price resulting from the transaction.

        In addition, the CIC Agreements for the Named Executive Officers provide that if their benefits exceed a specified amount, they will be reimbursed for the full amount of any excise taxes imposed on their severance payments and any other payments under Section 4999 of the Internal Revenue Code of 1986, as amended (the "Code"). This excise tax reimbursement is intended to make the executive whole for any adverse tax consequences that may result under Section 4999 of the Code with respect to the CIC benefits and to preserve the level of severance protections that the Board has determined to be appropriate for the Company's executives. The payment of severance benefits under the CIC Agreements is contingent upon the execution of a release of claims against the Company.

        Other than the CIC Agreements, the Company is not a party to any formal severance benefit arrangement or employment agreement with any Named Executive Officers except Mr. Thompson. Mr. Thompson's employment agreement, which was the result of arms length negotiation to incent Mr. Thompson to become CEO, prevents the Company from terminating his CIC Agreement during the term of his employment agreement, and his rights upon termination of employment are discussed in further detail below in the section titled "Employment, Severance and Change in Control Agreements and Arrangements for Fiscal Year 2010".

Tax Policy

        Section 162(m) of the Code limits the deductibility of cash compensation in excess of $1 million paid to the Chief Executive Officer and the three most highly compensated executives during any taxable year (other than the Chief Financial Officer), unless such compensation is considered "performance based compensation" that meets certain requirements. The Committee's intent generally is to design and administer the compensation program for the Company's executives in a manner that will preserve the deductibility of compensation paid to the Named Executive Officers and the Committee believes that its current compensation program generally satisfies the requirements for exemption from the Section 162(m) deduction limitation. The Committee reserves the right, however,

36

Table of Contents

to design programs that recognize a full range of performance criteria important to the Company's success even if certain aspects of the compensation paid under such programs may not be fully deductible. For example, restricted stock unit awards are not considered performance-based compensation under Section 162(m), and may not be fully deductible when paid.

        The Committee has considered and will continue to consider tax and other consequences in structuring its compensation arrangements with executives and will continue to ensure that the arrangements are reasonable and consistent with the goals of the Company and its stockholders.

COMPENSATION COMMITTEE REPORT ON EXECUTIVE COMPENSATION

        The Compensation Committee of the Board of Directors has reviewed and discussed the Compensation Discussion and Analysis required by Item 402(b) of Regulation S-K with management and, based on such review and discussions, has recommended to the Board that the Compensation Discussion and Analysis be included in this proxy statement.

THE COMPENSATION COMMITTEE

Kendall R. Bishop, Chairman
Jon Gacek
Kambiz Hooshmand

EQUITY COMPENSATION PLAN INFORMATION

        The Company currently maintains three equity compensation plans: the Power-One, Inc. Amended and Restated 1996 Stock Incentive Plan (the "1996 Plan"), the Power-One, Inc. 2001 Stock Option Plan (the "2001 Plan"), and the Power-One, Inc. Amended and Restated 2004 Stock Incentive Plan (the "2004 Plan"). With the exception of the 2001 Plan, each of these plans has been approved by the Company's stockholders.

        The following table sets forth, for each of the Company's equity compensation plans, the number of shares of common stock subject to outstanding options and other rights, the weighted-average exercise price of outstanding options, and the number of shares remaining available for future award grants as of January 2, 2011.

(1)

Of these shares, 2,425,090 were subject to stock options then outstanding under the 2004 Plan, 3,534,511 were subject to outstanding stock unit awards granted under the 2004 Plan, and 981,402 were subject to outstanding stock options under the 1996 Plan. No further awards may be granted under the 1996 Plan.

(2)

This number does not reflect the 3,534,511 shares that were subject to outstanding stock unit awards granted under the 2004 Plan.

37

Table of Contents

(3)

All shares available for future issuance are under the 2004 Plan. Subject to certain express limits of the 2004 Plan, shares available for award purposes under the 2004 Plan generally may be used for any type of award authorized under that plan including options, stock appreciation rights, and other forms of awards granted or denominated in shares of our common stock or units of our common stock including, without limitation, stock bonuses, restricted stock, and performance shares. Currently 3,206,318 shares are available for full value awards under the 2004 Plan.

(4)

All of these shares were subject to awards granted under the 2001 Plan. The 2001 Plan was adopted in September 2001, per applicable regulations and exchange listing rules, as an equity compensation plan not approved by security holders. The 2001 Plan is administered by our Compensation Committee. Awards under the 2001 Plan may only be nonstatutory stock options. No awards under the 2001 Plan may be made to any Director of the Company or to any person who is an officer within the meaning of Section 16 of the Securities Exchange Act of 1934, as amended. The maximum term of options granted under the 2001 Plan is 10 years after the grant date of the award. No new awards may be granted under the 2001 Plan. Options granted under the 2001 Plan have been granted at the "fair market value" of the underlying shares (i.e. the closing price of our stock on the date the option is granted). Generally, awards that are not yet exercisable will terminate upon the date the grantee is no longer employed by the Company, and those that are exercisable will remain exercisable for ninety (90) days after the end of employment.

EXECUTIVE OFFICERS

        Information regarding each of the Named Executive Officers is included in Part I, Item 1, under the caption "Executive Officers of the Registrant" in the Company's Annual Report on Form 10-K for the fiscal year ended January 2, 2011 and is hereby incorporated by reference into this proxy statement.

38

Table of Contents

SUMMARY COMPENSATION TABLE

        The following table presents information regarding compensation of individuals who during fiscal 2010 served as the Company's (i) principal executive officer, (ii) principal financial officer; and (iii) the next three most highly compensated executive officers who earned at least $100,000 during fiscal 2010.

(1)

The amounts reported in column (e) reflect the aggregate grant date fair value computed in accordance with FASB ASC Topic 718 share-based compensation expense for outstanding restricted stock unit awards as to which the restrictions have not lapsed. See Note 14 to Consolidated Financial Statements contained in our Annual Report on Form 10-K for the year ended January 2, 2011 for a discussion of assumptions made in valuation of share based compensation. The amounts reported reflect the aggregate dollar amounts recognized for stock awards for financial statement reporting purposes, disregarding any estimate of forfeitures related to service-based vesting conditions.

(2)

The amounts reported in column (f) reflect the aggregate grant date fair value computed in accordance with FASB ASC Topic 718 share-based compensation expense during fiscal 2010 for outstanding stock option and stock appreciation right ("SAR") awards. See Note 14 to Consolidated Financial Statements contained in our Annual Report on Form 10-K for the year ended January 2, 2011 for a discussion of assumptions made in valuation of share-based compensation.

(3)

The amounts reported in column (g) were for payouts earned under the 2010 MIP (discussed in "Short-Term Incentives—Cash Bonus Plans" above in the Compensation Discussion and Analysis), but were not paid until fiscal 2011.

(4)

The amounts in column (h) for each of the Named Executive Officer's includes the following: Thompson-$48,000 (living allowance), $13,260 (auto allowance), $9,800 (Company match to 401K plan), $5,460 premiums paid for the executive medical plan and life insurance); Larsen—$24,000 (living allowance), $2,700 (auto allowance), $3,792 (Company match to 401K plan), $1,980 (premiums paid for the executive medical plan and life insurance), $6,574 (relocation reimbursement); Heller—$280,000 (severance), $5,100 (auto allowance), $6,531 (Company match to 401K plan), $5,300 (premiums paid for the executive medical plan and life insurance); Dial—$40,000 living allowance, $7,800 auto allowance, $9,800 (Company match to 401K plan), $5,940 (premiums paid for the executive medical plan and life insurance); Levran—$7,800 auto allowance, $8,754 Company match to 401K plan, $5,460 premiums paid for the executive medical and life insurance; McKnight—$7,800 (auto allowance), $9,430 (Company match to 401K plan) and $5,700 (premiums paid for the executive medical plan and life insurance).

GRANTS OF PLAN BASED AWARDS—FISCAL 2010

        The following table provides information regarding the awards under the Company's 2010 MIP and under the 2004 Plan. There were no equity-based incentive awards granted to the Named

39

Table of Contents

Executive Officers during fiscal 2010, other than the restricted stock unit awards and stock option awards disclosed below. The Named Executive Officers earned payouts subject to a two times multiplier of target under the terms of the 2010 MIP, as reflected in column (e) below, although payments were not made to the Executives until 2011.

Narrative for Summary Compensation Table and Grants of Plan-Based Awards Table

        As noted in the "Compensation Discussion and Analysis" above, none of the Named Executive Officers are covered by employment agreements except Mr. Thompson. The Company and Mr. Thompson entered into an employment agreement on February 18, 2008, which provided for a two-year initial term with automatic annual renewals thereafter. The agreement provided for an initial base salary of $500,000. His employment agreement further entitled him to a target incentive payment equal to 100% of his base salary during each year of his employment. In addition, the employment agreement provided Mr. Thompson with an award of 450,000 restricted stock units, 500,000 options and 250,000 SARs. The restricted stock units vest in substantially equal annual installments on each of the first four anniversaries of the effective date of the Employment Agreement. The stock options and SAR grants awarded to Mr. Thompson fully vest on the fourth anniversary of each of the respective grant dates; however 50% of the options and SARs were subject to vesting on March 1, 2010 if (A) the closing price per share of the Company's Common Stock on the principal exchange on which such stock is traded on any 20 out of 30 consecutive trading days in the period beginning October 1, 2009 and ending March 1, 2010 exceeded 150% of the exercise price of the awards and (B) the Company's consolidated net income for the 2009 calendar year as determined under GAAP equaled or exceeded 5% of the Company's consolidated net sales revenue for such period determined under GAAP. The

40

Table of Contents

Company's consolidated net income target was not achieved and the options and SARs did not vest at that time. On March 1, 2011, Mr. Thompson vested in 75% of the options and SARs because (X) the closing price per share of the Company's Common Stock on the principal exchange on which such stock is traded on any 20 out of 30 consecutive trading days in the period beginning October 1, 2010 and ending March 1, 2011 exceeded 160% of the exercise price of the awards and (Y) the Company's consolidated net income for the 2010 calendar year as determined under GAAP exceeded 7.5% of the Company's consolidated net sales revenue for such period determined under GAAP.

        The Company is also party to at-will offer letters with Gary Larsen and Neil Dial. The offer letter with Mr. Larsen dated August 10, 2010, and filed as an exhibit to the Form 10-Q filed on November 12, 2010 provides for an initial base salary of $325,000 and a target annual incentive payment equal to 60% of base salary. The offer letter with Mr. Larsen also provided for an award of a non-qualified stock option to purchase 100,000 shares of Power-One common stock, and 100,000 restricted stock units, both vesting over four years at 25% per year. The offer letter with Mr. Dial, dated August 12, 2008 and filed as exhibit to the Form 8-K filed on October 1, 2008, provides for an initial base salary of $350,000 and a target annual incentive payment equal to 60% of base salary. The offer letter with Mr. Dial also provided for an award of 250,000 options, which vest in full on the fourth anniversary of the grant date, subject to accelerated vesting as follows: (A) 50% of the options vest if, after the first anniversary of the grant date, the closing price per share of the Company's Common Stock on the principal exchange on which such stock is traded on any 20 out of 30 consecutive trading days exceeds 175% of the exercise price of the awards (the target stock price was achieved and 50% of Mr. Dial's options vested on October 30, 2009) and (B) the remaining 50% of the options vest if, after the second anniversary of the grant date, the closing price per share of the Company's Common Stock on the principal exchange on which such stock is traded on any 20 out of 30 consecutive trading days exceeds 275% of the exercise price of the awards. The target stock price was achieved and the remaining 50% of Mr. Dial's options vested on September 29, 2010.

        The amounts set forth above in "Estimated Payouts Under Non-Equity Incentive Plan Awards" reflect amounts that each Named Executive Officer was eligible to earn under the 2010 MIP discussed above in the "Short Term Incentives—Cash Bonus Plans" section of the "Executive Compensation Discussion and Analysis" under each of the bonus tiers established under the plan.

        Each of the equity-based awards reported in the Grants of Plan-Based Awards Table was granted under, and is subject to, the terms of the 2004 Plan. The 2004 Plan is administered by the Compensation Committee. The Compensation Committee has authority to interpret the plan provisions and make all required determinations under the plan. This authority includes making required proportionate adjustments to outstanding awards upon the occurrence of certain corporate events such as reorganizations, mergers and stock splits, and making provision to ensure that any tax withholding obligations incurred in respect of awards are satisfied. Awards granted under the plan are generally only transferable to a beneficiary of a Named Executive Officer upon his or her death. However, the Compensation Committee may establish procedures for the transfer of awards to other persons or entities, provided that such transfers comply with applicable securities laws and, with limited exceptions set forth in the plan document, are not made for value.

        All restricted stock unit awards reported in the table above are scheduled to vest 33.33% at each of the first, second and third anniversaries of the date of the initial award, except Mr. Larsen's equity award, which vests over four years, and the restricted stock unit awards and stock options awarded on June 1, 2010, which vest over four years. All restricted stock units are payable in shares of the Company's Common Stock on a one-for-one basis following the vesting date and include the right to receive dividend payments.

41

Table of Contents

OUTSTANDING EQUITY AWARDS AT FISCAL 2010 YEAR-END

        The following table presents information regarding the outstanding equity awards held by each of our Named Executive Officer's as of January 2, 2011.