The report is published on the website of the Energy & Utilities Alliance, at http://www.eua.org.uk/%E2%80%98gas-storage-delivers-lower-transmission-costs%E2%80%99-says-new-report
The full report ("UK gas transmission system benefits from gas storage - an update to the initial report produced in 2007" - A report for GSOG, prepared by Waters Wye Associates (version 0.4, 23 April 2013)) can be found at http://www.eua.org.uk/sites/default/files/WWA-Gas-Transmission-Benefits-of-GB-Gas-Storage-Report.pdf