A price-droop trading strategy for residential photovoltaic-battery systems

Residential photovoltaic-battery systems (RPBSs) are widely applied to improve the controllability and predictability of rooftop solar photovoltaic systems (RSPSs). High investments of the RPBSs demand new trading strategies to promote their applications. A price-droop trading strategy is proposed in this paper to satisfy the investors' demands. The RPBSs are formulated as virtual power plants (VPPs) in the price-droop trading strategy. The electricity price of the VPPs is adaptive to their output power. The object of the price-droop trading strategy is VPPs' daily profit maximization, which can be solved as a convex quadratic optimization problem. The price-droop trading strategy is validated by two RPBSs with time-varying electricity price. Results show that the price-droop trading strategy ensures more controllable and predictable RPBSs' output power. Its extra economic profit will encourage more residents to invest the RPBSs. Increments of RPBSs will promote the utilization of the photovoltaic resources.