Power can be time shifted from a period of low price to high price by energy storage, with an efficiency penalty; pumped storage is a common form of energy storage. Fourteen deregulated markets are ranked based on available revenue and potential return on investment; the incentive to store energy varies significantly between markets.; In addition, a model is developed to maximize the return on pumped storage investment by varying the generation capacity for a given reservoir. The amount of power stored (MWh) is set by the reservoir capacity; the rate of recovery of stored energy (MW) is set by the capacity of the pump/generator. Two examples from Alberta confirm that the size of pump/generator relative to reservoir that optimizes daily operating time and return on investment depends on each of: the deregulated power market (diurnal price pattern), the site within the power market (site specific interconnection charges), and the storage technology (energy efficiency). |