Lifetime-dependent battery usage optimization for grid-connected residential systems

Abstract

Batteries are an important element for residences that are in grid-connected systems with energy procurement. They provide storage for local generation and a buffer against the inconsistent output from renewables such as rooftop solar. In addition, they can independently provide a medium for buying and selling retail energy. The growing deployment of reverse power-operation systems provides residences with the ability to buy and sell energy at the retail time-of-use rate. While the nonlinear models of chemical batteries have been extensively studied, they have not been applied to strategies for residential battery use. In this work, we develop a formulation for battery usage based on more realistic battery models, optimizing the benefit of discharging the battery. We design the scheme for the actual use of batteries in an energy-trading environment, considering the total cost of ownership and return on investment. Finally, we simulate the system in different geographic locations using the actual time-of-use pricing for each, and demonstrating return on investment in as few as 5 years.