As the interest in energy storage units is increasing in the power sector, significant effort is being put into evaluating technological and business opportunities. However, many studies narrow their examinations and pursue a single goal, which may create false enthusiasm for energy storage. To tackle such issues, complex technical-economical case studies are necessary, with solid input data and real life applications, where the application of storage could generate revenue. In this paper, a recent study is presented, which aimed to examine the profitability of an energy storage unit, installed at an industrial or commercial consumer. The storage strategy was created through an optimization process considering two aspects: to decrease the power draw from the grid during peak hours and to decrease energy consumption of peak hours by shifting the needs to off-peak periods. A quasi-automatic decision support system was developed, which can determine parameters of the storage unit based on user defined inputs. Market potential of the idea was evaluated using data of a group of potential customers. Results have shown that the specified application can create positive net present value under certain circumstances.