Exhibit 15 To the Board of Trustees Northeast Utilities Berlin, Connecticut We have made a review, in accordance with standards established by the American Institute of Certified Public Accountants, of the unaudited interim financial information of Northeast Utilities and subsidiaries for the period ended March 31, 2002, as indicated in our report dated May 10, 2002; because we did not perform an audit, we expressed no opinion on that information. We are aware that our report referred to above, which is included in your Quarterly Report on Form 10-Q for the quarter ended March 31, 2002, is incorporated by reference in Registration Statement Nos. 33-34622, 333-55142 and 33-40156 on Forms S-3 and Nos. 33-44814, 33-63023, 333-52413 and 333-52415 on Forms S-8 of Northeast Utilities. We also are aware that the aforementioned report, pursuant to Rule 436(c) under the Securities Act of 1933, is not considered a part of the Registration Statement prepared or certified by an accountant or a report prepared or certified by an accountant within the meaning of Sections 7 and 11 of that Act. /s/ Deloitte & Touche LLP Deloitte & Touche LLP Hartford, Connecticut May 10, 2002