Abstract: A method for improving electrical generator efficiency using a rechargeable battery includes, at a computer system, determining a load from an electrical-power consumption entity for a prospective time period; and calculating a first supply from a renewable electrical power supply source for the same prospective time period. The renewable electrical-power supply source comprises one or more photovoltaic devices, and the renewable electrical-power supply source is independent from a power grid. The method also includes quantifying a deficiency in an ability of the first supply to satisfy the load during the prospective time period; and in accordance with the quantification of the deficiency in the ability of the first supply to satisfy the load during the prospective time period: optimizing a spinning reserve schedule for a plurality of power generators to thereby make up the deficiency. The optimization of the spinning reserve schedule improves the non-renewable energy consumption.