UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d)

of the Securities Exchange Act of 1934

Date of report (Date of earliest event reported): November 4, 2014

EnerNOC, Inc.

(Exact Name of Registrant as Specified in Charter)

Registrant’s telephone number, including area code: (617) 224-9900

N/A

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

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

On November 4, 2014, EnerNOC, Inc. (the “Company”) issued a press release announcing the execution of an Agreement and Plan of Merger (the “Merger Agreement”) with World Energy Solutions, Inc. (“Target”). Pursuant to the Merger Agreement, Wolf Merger Sub Corporation, a wholly-owned subsidiary of the Company (“Purchaser”) will commence a tender offer to purchase all of the issued and outstanding shares of Target’s common stock for $5.50 per share in cash. If successful, the tender offer will be followed by a merger of Purchaser with and into Target. A copy of the press release is attached hereto as Exhibit 99.1 and is incorporated herein by reference.

On November 4, 2014, the Company sent an email to its employees and issued FAQs regarding the execution of the Merger Agreement. The email and the FAQs are attached hereto as Exhibit 99.2 and Exhibit 99.3, respectively, and are incorporated herein by reference.

Cautionary Statement Regarding Forward-Looking Statements

This communication contains forward-looking statements. These forward-looking statements reflect the views of the Company’s and Target’s management regarding current expectations and projections about future events and the ability of the Company and Target to complete the transactions contemplated by the Merger Agreement, including the parties’ ability to satisfy the conditions to the consummation of the tender offer and the other conditions set forth in the Merger Agreement, and are based on currently available information. These forward-looking statements are not guarantees of future performance and are subject to risks, uncertainties and assumptions that are difficult to predict; therefore, actual results may differ materially from those expressed, implied or forecasted in any such forward-looking statements. Expressions of future goals and similar expressions including, “may,” “will,” “should,” “could,” “expects,” “plans,” “anticipates,” “intends,” “believes,” “estimates,” “predicts,” “potential,” “targets,” or “continue,” reflecting something other than historical fact are intended to identify forward-looking statements. The proposed transaction has not closed, and the following factors, among others, could cause actual results to differ materially from those described in the forward-looking statements: the possibility that expected benefits of the transaction may not be achieved in a timely manner or at all; revenues following the transaction may be lower than expected; disruption from the transaction may adversely affect Target’s relationships with its customers, business partners or employees; the conditions to the completion of the transaction may not be satisfied in a timely manner or at all; and the other factors described in the Company’s and Target’s most recent Quarterly Report on Form 10-Q and Annual Report on Form 10-K filed with the Securities and Exchange Commission. Unless required by law, neither the Company nor Target undertakes any obligation to update publicly any forward-looking statements, whether as a result of new information, future events or otherwise.

Important Information

This communication is not an offer to buy or the solicitation of an offer to sell any shares of World Energy Solutions, Inc. common stock. The tender offer described herein has not yet been commenced. On the commencement date of the tender offer, an offer to purchase, a letter of transmittal and related documents will be filed with the Securities and Exchange Commission (SEC). The solicitation of offers to buy shares of World Energy Solutions, Inc. common stock will only be made pursuant to the offer to purchase, the letter of transmittal and related documents. Investors and World Energy Solutions, Inc. securityholders are strongly advised to read both the tender offer statement and the solicitation/recommendation statement that will be filed by World Energy Solutions, Inc. regarding the tender offer when they become available as they will contain important information. Investors and securityholders may obtain free copies of these statements (when available) and other documents filed with respect to the tender offer at the SEC’s website at www.sec.gov. In addition, copies of these statements and related documents (when available) may be obtained for free by directing such requests to the information agent for the tender offer, which will be named in the tender offer statement.

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Item 9.01. Financial Statements and Exhibits.

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SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

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EXHIBIT INDEX

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