A method includes obtaining a state of charge (SOC) schedule for an energy storage device and a time-dependent forecast of electrical energy production by a renewable electrical energy generation resource; generating a time-varying charge/discharge control signal for the electrical energy storage device based on the time-dependent forecast of electrical energy production, wherein the time-varying charge/discharge control signal is configured to maintain an average SOC of the energy storage device as low as possible while satisfying the SOC schedule; and controlling charging and discharging of the energy storage device with the time-varying charge/discharge control signal.