The Energy Charter Treaty and its associated Protocol on Energy Conservation is the first binding international law document which imposes obligations on states to reduce energy consumption in all sectors of the economy. This paper considers the extent of the obligations imposed by the Treaty and Protocol, and examines which obligations are binding as opposed to merely hortatory and how international law interacts in this field with each country＇s domestic laws. The paper concludes with a preview of likely future developments and modifications to the Energy Charter Treaty, including the likelihood and possible contents of further future Protocols.