Within the context of an evolving global market for natural gas and restructuring efforts in the European market, gas storage is an important element. Providing additional flexibility, promoting competition, and enhancing supply security are crucial factors for natural gas sector liberalization. Storage in Europe has come to the center of the energy policy debate mainly due to very cold temperatures in winter 2005/06 and gas price increases during that time period. This book covers four main topics: development of commercial storage; access regulation; capacity allocation and market power; storage and security of gas supply. Each Chapter puts forth an innovative analytical model discussed or applied to realistically explain specific issues in one of the four biggest European gas consuming countries (France, Germany, Italy and the UK).