National Grid LNG, L.P., Semi-Annual Storage Report from November 1, 2010 through March 31, 2011 and National Grid LNG l.P./KeySpan LNG, L.P. Semi-Annual Storage Reports from 4/1/05 through 10/31/10

CD CULLENandDYKMANLLP 110114th Street,N.W. NAME:KENNETHT.MALONEY Suite550 Title:Partner Washington,D.C.200055600 kmaloney@cullenanddykman.com Telephone:2022238890Fax:2024571405 April 29, 2011 Kimberly Bose, Secretary Federal Energy Regulatory Commission 888 First Street, N.E. Room 1A Washington, D.C. 20426 Re: National Grid LNG, L.P. KeySpan LNG, L.P. Semi-Annual Storage Reports 18 C.F.R. 284.13(e) Dear Secretary Bose: Enclosed for electronic filing on behalf of National Grid LNG, L.P. (National Grid LNG) is its Semi-Annual Storage Report for the period November 1, 2010 through March 31, 2011. Also enclosed on behalf of National Grid LNG and its predecessor KeySpan LNG, L.P. are the semi-annual storage reports for the following past periods: (1) April 1, 2005 through October 31, 2005; (2) November 1, 2005 through March 31, 2006; (3) April 1, 2006 through October 31, 2006; (4) November 1, 2006 through March 31, 2007; (5) April 1, 2007 through October 31, 2007; (6) November 1, 2007 through March 31, 2008; (7) April 1, 2008 through October 31, 2008; (8) November 1, 2008 through March 31, 2009; (9) April 1, 2009 through October 31, 2009; (10) November 1, 2009 through March 31, 2010; and (11) April 1, 2010 through October 31, 2010. A signed affidavit from a senior officer verifying the reports is also enclosed. National Grid requests such waivers of the Federal Energy Regulatory Commissions regulations as may be necessary to accept the past period reports out of time. National Grid Honorable Kimberly Bose, Secretary Page 2 April 29, 2011 LNG, formerly known as KeySpan LNG, became affiliated with National Grid plc. when it acquired KeySpan Corporation in August 2007. Since that time, National Grid has engaged in a comprehensive effort to ensure that all of its affiliates are in compliance with the regulatory requirements of the Commission and other regulatory authorities having jurisdiction. National Grid LNGs submission of its semi-annual storage reports at this time is in furtherance of this effort. Accordingly, the acceptance of the enclosed reports at this time is consistent with the public interest. Please contact the undersigned if you have any questions. Yours truly, /s/Kenneth T. Maloney Kenneth T. Maloney Counsel For National Grid LNG, L.P. KeySpan LNG, L.P. Summary of Storage Injection and Withdrawal Activities For the Period - 4/1/2005 through 10/31/2005 Maximum Maximum Daily Actual Reservation Displacement Total Storage Quantity Withdrawal Quantity Quantities Actual Quantities Charge Charge Revenues Discounts Customer Affiliate (Y/N) Rate Schedule (Dth) (Dth) Injected (Dth) Withdrawn (Dth) ($/Dth/mo.) ($/Dth/mo) Received ($/Dth/mo) April CONSOLIDATED EDISON COMPANY OF NEW YORK,INC N FST-LG 500,000 20,000 - - $ 0.2625 $ 0.0417 $ 152,100 $ 0.0104 BOSTON GAS COMPANY Y FST-LG 1,159,664 35,000 17,737 - $ 0.2625 $ 0.0417 $ 352,770 $ 0.0104 PROVIDENCE GAS COMPANY N FST-LG 600,000 95,000 14,643 - $ 0.2625 $ 157,500 $ 0.0104 Total - April 2,259,664 15