As a result of storability restrictions, the price risk management of flow commodities (such as natural gas, oil, and electrical power) is by no means a trivial matter.To protect price spikes, consumers purchase diverse swing-type contracts, whereas contract writers try to hedge themselves by appropriate physical assets, for instance, using storage utilities, through transmission and/or production capacities. However, the correct valuation of such contacts and their physical counterparts is still under lively debate. In this approach, an axiomatic setting to discuss price dynamics for flow commodity contracts is suggested. By means of a minimal set of reasonable assumptions we suggest a framework where the standard change-of-numeraire transformation converts a flow commodity market into a market consisting of zero bonds and some additional risky asset. Utilizing this structure, we apply the toolkit of interest rate theory to price the availability of production capacity on a flow commodit
