1. Confidential DN Interruption Tenders 2008 Interruption Seminar Ofgem 19 th August 2008 Version 1.0 Final

2. Confidential Summary of June 08 Tender  48 bids received for 29 supply points across 18 (out of 29) Locations  Bids accepted for 5 Supply points in 4 Locations:  EA – Fakenham HP  NW – Barrow HP  NW – Barrowford HP  NW – Winsford HP  Price and capacity information (as per spreadsheet) published on Joint Office and NG website www.nationalgrid.com/ uk/Gas/OperationalInfo/interruptionstosupply/dn_+interruption_reform  Shipper meetings arranged  Feedback on June 08 tender  Discuss requirements for ad-hoc tender  Ad-hoc tender to be held in Sept-Nov 2008  Interruption Requirements published 8 th September  Bid window 13 th -24 th October  Results notified – 21 st November

3. Confidential National Grid - June 2008 DN Interruption Tender Results Summary

4. Confidential Ad-hoc tender – Indicative Locational Interruption Requirements - East Anglia LDZInterruption Zone PostcodesInterruptible Allowance (days) Interruptible Capacity Estimate (GWh/d) MinMax EAStowmarketIP6, IP8, IP14, IP305300.69

5. Confidential Ad-hoc tender – Indicative Locational Interruption Requirements - East Midlands LDZInterruption Zone PostcodesInterruptible Allowance (days) Interruptible Capacity Estimate (GWh/d) MinMax EMDigbyLN45100.11 EMBurtonDE12, DE13, DE14, DE655200.33 EMCoalvilleLE675100.18 EMClay CrossS45, DE555100.12 EMWorksopS80, S815100.53 EMDoncasterDN4, DN55250.17 EMBarnby DunnDN1-3, DN7, DN85251.13 EMBarnsleyS70-S755451.84 EMScunthorpeDN15-195451.51

6. Confidential Ad-hoc tender – Indicative Locational Interruption Requirements - North West LDZInterruption Zone PostcodesInterruptible Allowance (days) Interruptible Capacity Est. (GWh) MinMax NWEarbyBB18, BB9, BB8, BD235150.14 NWAccringtonBB55400.17 NWNorth lakesLA8-9, LA21-235451.11 NWStalybridgeOL65100.12 NWAppleby BridgeWN65400.11 NWKnutsfordWA165450.24 NWHall GreenSK9, SK105451.12 NWRamsbottomBL0, BL8, BL95450.65 NWWinsfordCW7, CW9, CW105150.10 NWBramhallSK75450.14

7. Confidential Ad-hoc tender – Indicative Interruption Requirements (LTS) LDZInterruption Zone PostcodesInterruptible Allowance (days) Interruptible Capacity Est. (GWh/d) MinMax EAFakenham HPNR21, NR225200.14 EMGrantham HPNG315100.13 EMHooton Roberts HPDN4, DN12, S63, S645100.14 EMThrapston HPNN3, NN5, NN6, NN8, NN9, NN14, NN29 5100.38 EMTotley HPMK16, NN1, NN4, NN5, NN6, NN7, LE17 5101.3 NWBarrow HPLA12, LA14, LA185103.5 NWBarrowford HPBB1-3, BB5-12, BB185100.1 NWNew Mills HPSK1, SK4-8, SK12-14, SK16, SK22 5100.24 NWNorth West HPCW9, L24, M17, WA7-1051544.9 NWWinsford HPCW7-10, M5, M14, M19, M22- 24, M31, M34, M41, M90 5151.91

8. Confidential Tender Design SPIDTrancheSOQSHQPriceDays of Interruption e.g. Contract Period OptionEx.5101512345 maximum number of offers per tranche/supply point = 10 If tranches, must be able to accept one offer per tranche All contracts start in Year 1 (1 Oct 2011) If offers for multiple years then must be same for each year Users indicate mutually exclusive offers – must be able to select one offer from set of linked offers Interruptible allowances in multiples of 5 days