In the literature, one approach is to analyse gas storage within a simple one-factor price dynamics framework that is solved to optimality. We follow an alternative approach, where the market is represented by a forward curve with daily granularity, the price uncertainty is represented by six factors, and where we impose a simple and intuitive storage strategy. Based on UK natural gas market price data, we obtain the gas storage value using our approach, and compare with results from a one-factor model as well as with perfect foresight. We find that our approach captures much more of the true flexibility value than the one-factor model.