Reliability and Cost Impacts of Home Energy Management Systems

This paper aims to analyze the reliability effects and cost changes when Home Energy Management System (HEMS) is applied to a large number of homes within a distribution system. HEMS optimizes the daily operation of loads and resources in a home (e.g., smart appliances, thermostatically controlled loads, photovoltaics (PVs), storage, etc.) with the objective of minimizing incurred cost on the household, under time-of-use electricity pricing. The HEMS problem in this paper is formulated as a mixed integer linear programming problem. The optimization is performed for multiple home types across an entire year to compute the annual load profile of a feeder under study. The method is demonstrated on an example distribution test feeder supplying 1000 homes. Subsequently, the example is extended to a distribution substation comprising 11 distribution feeders. The feeder results indicate the generation of peaks at times of low electricity prices, as expected. These results are utilized to compute the impact on system reliability and production costs using the probabilistic production costing method. The system results show that while HEMS creates peaks in feeder loads, system reliability and system production costs are improved.