Energy cost reduction by optimal control of ideal sensible thermal energy storage in domestic space heating

In the light of demand side management, the combination of thermal energy storage and space heating using electricity as energy vector is promising. The environmental gains of the use of heat pumps in buildings increase as the fraction of renewable electricity production rises. When variable electricity prices represent the availability of renewable energy sources, consumer gain can be accompanied by environmental benets. The aim of this study is to determine the potential in energy cost reduction when using sensible thermal energy storage in a domestic space heating context. To fully investigate the potential of thermal energy storage, an optimal control strategy is applied to two idealized sensible energy storage tanks. The cost for space heating in a single-family dwelling using a sensible thermal energy store for diurnal storage is compared with a reference cost, without storage capacity present. As the cost reduction is dependent on the match between the energy use prole and the energy price prole, two energy pricing schemes are studied: a day-night tari according to local electricity prices and a quarter-hour energy pricing scheme based on the daily variation of nationwide energy use. The resulting control profiles and variation of storage state of charge are presented for several values of storage capacity. The space heating energy cost is calculated for each case and compared for the stratied and mixed storage tanks and the reference cost. The results indicate a potential for user cost reduction of up to 20% using the perfectly stratied storage model.status: publishe