CASE STUDY UNDERGROUND GAS STORAGE PROJECT YELA ENAGAS

CASE STUDY UNDERGROUND GAS STORAGE PROJECT “YELA” ENAGAS S. A. Brussels, 24 th May 2007

MAIN FEATURES YELA 2

MAIN FEATURES YELA Promoter: ENAGAS S. A YELA Type: Aquifer Location: <100 km. from Madrid Capacity Data: >1. 000 Mcm -Working Volume: PROJECT SCHEDULE GEOLOGICAL EXPLORATION IN SPAIN -Withdrawal: ~ 15 Mm 3/day -Injection: ~ 5 Mm 3/day GEOLOGY AND GEOPHYSICS TESTS + PERMITS & PERMISSIONS 2002 CONSTRUCTION & FIRST START-UP 2007 3 2011 BUILD-UP 2020

INVESTMENT/REMUNERATION/TARIFFS INVESTMENT/FINANCING Facilities ~ 150 - 200 M€ Cushion Gas ~ 250 - 300 M€ (10 years) 400 - 500 Financing Option M€ Corporate Finance REMUNERATION (Regulated Activity) Based on properly Audited Costs (Cost-Based) ROR at least WACC + 3 % TARIFFS Design Type Total Cost / service pure r-TPA 4

IMPACT ON THE SPANISH STORAGE 106 TWh LNG STORAGE CAPACITY + 81 % UNDERGROUND STORAGE 43 TWh + 185 % Storage/Residential Demand ratio 5 FUTURE 2007 (Mandatory Planning) 83 % 134 %

Disclaimer This document may contain market assumptions, different sourced information and forward-looking statements with respect to the financial condition, results of operations, business, strategy and the plans of Enagas SA. Such statements are based on a number of assumptions that could ultimately prove inaccurate and are subject to a number of risk factors, including the ability to realize cost reductions and operating efficiencies without unduly disrupting business operations, environmental, regulatory considerations and general economic and business conditions. Enagas does not assume any obligation to update publicly any forwardlooking statements as a result of new information or future events. Further information on factors which could affect the company's financial results is provided in documents filed by the company and submitted to the CNMV. Any data contained herein for periods 2000 and earlier was prepared by using historical proforma results. Proforma financial data is unaudited and calculated applying company's accounting principles. 6

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