NSTAR ELECTRIC COMPANY 5.625% DEBENTURE DUE 2017 THIS SECURITY IS A REGISTERED SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF THE DEPOSITORY TRUST COMPANY OR A NOMINEE THEREOF

Exhibit 99.2

NSTAR ELECTRIC COMPANY

5.625% DEBENTURE DUE 2017

THIS SECURITY IS A REGISTERED SECURITY WITHIN THE MEANING OF THE INDENTURE HEREINAFTER REFERRED TO AND IS REGISTERED IN THE NAME OF THE DEPOSITORY TRUST COMPANY OR A NOMINEE THEREOF.

Unless this Security is presented by an authorized representative of The Depository Trust Company, a New York corporation (“DTC”), to NSTAR ELECTRIC COMPANY or its agent for registration of transfer, exchange, or payment, and any certificate issued is registered in the name of Cede & Co. or in such other name as is requested by an authorized representative of DTC (the “Registered Owner”) (and any payment is made to Cede & Co. or to such other entity as is requested by an authorized representative of DTC), ANY TRANSFER, PLEDGE, OR OTHER USE HEREOF FOR VALUE OR OTHERWISE BY OR TO ANY PERSON IS WRONGFUL inasmuch as the registered owner hereof, Cede & Co., has an interest herein.

NSTAR ELECTRIC COMPANY, a corporation duly organized and validly existing under the laws of The Commonwealth of Massachusetts (herein called the “Company,” which term includes any successor corporation under the Indenture hereinafter referred to), for value received, hereby promises to pay to the Registered Owner, or registered assigns, the principal amount specified in the title of this security (the “Principal Amount”) on the Stated Maturity, except to the extent redeemed prior to the Stated Maturity, and to pay interest on said principal sum semiannually on each Interest Payment Date, commencing May 15, 2008, at the rate per annum specified in the title of this Security, from November 15 or May 15, as the case may be, next preceding the date of this Security to which interest has been paid unless the date hereof is a date to which interest has been paid, in which case from the date of this Security, or unless no interest has been paid on this Security, in which case from the date of initial issuance until payment of said principal sum has been made or duly provided for and at such rate on any overdue principal and premium and (to the extent that the payment of such interest shall be legally enforceable) on any overdue installment of interest. If any Interest Payment Date falls on a day that is not a Business Day, the interest payment will be made on the next Business Day, but will deem that payment was made on the date that payment was due. No interest will accrue on

the amount payable for the period from the actual payment date to such next Business Day. The interest so payable, and punctually paid or duly provided for, on any Interest Payment Date will, except as otherwise provided in said Indenture, be paid to the Person in whose name this Security (or one or more Predecessor Securities) is registered at the close of business on November 1 or May 1, as the case may be, next preceding such November 15 or May 15. The principal of (and premium, if any) and interest on this Security are payable in such coin or currency of the United States of America as at the time payment is legal tender for payment of public and private debts, at the office or agency of The Bank of New York Trust Company, N. A. (hereinafter called the “Indenture Trustee,” which term includes any successor Indenture Trustee under the Indenture), as Indenture Trustee and Paying Agent, located at 101 Barclay Street, New York, New York 10286, or at such other office as the Indenture Trustee shall designate by written notice to the Registered Owner of this Security; provided that interest shall be paid by wire transfer in immediately available funds to an account located in the United States of America as the registered Holder hereof shall designate to the Indenture Trustee in writing at least 15 business days prior to such Interest Payment Date. Any interest not punctually paid or duly provided for shall be payable as provided in the Indenture.

REFERENCE IS HEREBY MADE TO THE FURTHER PROVISIONS, INCLUDING THE OPTIONAL REDEMPTION PROVISIONS, OF THIS SECURITY SET FORTH ON THE REVERSE HEREOF, WHICH FURTHER PROVISIONS SHALL FOR ALL PURPOSES HAVE THE SAME EFFECT AS IF SET FORTH AT THIS PLACE. UNLESS THE CERTIFICATE OF AUTHENTICATION HEREON HAS BEEN EXECUTED BY THE TRUSTEE BY MANUAL SIGNATURE, THIS SECURITY SHALL NOT BE ENTITLED TO ANY BENEFIT UNDER THE INDENTURE, OR BE VALID OR OBLIGATORY FOR ANY PURPOSE.

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IN WITNESS WHEREOF, the Company has caused this instrument to be duly executed under its seal.

INDENTURE TRUSTEE’S CERTIFICATE OF AUTHENTICATION

This is one of the Securities of the series designated therein referred to in the within-mentioned Indenture.

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(Reverse of Security)

This Security is one of a duly authorized issue of securities of the Company (herein called the “Securities”) issued under the Indenture, dated as of September 1, 1988, as supplemented, between the Company and The Bank of New York Trust Company, N. A. (formerly Bank of Montreal Trust Company), as Indenture Trustee, to which Indenture and all other indentures supplemental thereto reference is hereby made for a statement of the respective rights thereunder of the Company, the Indenture Trustee and the Holders of the Securities and the terms upon which the Securities are, and are to be, authenticated and delivered. This Security is one of the series designated as the 5.625% Debentures due November 15, 2017.

The Securities are redeemable, in whole or in part, at the Company’s option at any time. The redemption price for the Securities to be redeemed will equal the greater of the following amounts, plus, in each case, accrued interest thereon to the redemption date: (i) 100% of the principal amount of the Securities to be redeemed and (ii) as determined by the Quotation Agent (as defined herein), the sum of the present values of the remaining scheduled payments of principal and