Buffer sizing of concentrated photovoltaic batteries: An economic analysis

Energy storage systems are one of the major components in today´s grid-tied photovoltaic technology. The most widespread ESSs are the batteries mounted on electric vehicles. Second-life batteries, regardless of the technology, are less expensive than new battery packs. The proper sizing of concentrated photovoltaic buffers and the true economic feasibility need to be investigated thoroughly before any large-scale photovoltaic grid integration. This paper investigates the economic performance of grid-tied concentrated photovoltaics and buffers. Simulation results show that not only is the combined unit capable of connection to the grid during the day at a constant 20 kW, but also was able to shift the less valuable off-peak electric supply to the on-peak supply, where the cost of electricity was higher. This paper addresses (1) techniques behind battery-sizing scenarios, (2) battery-parameter calculations involved in concentrated photovoltaic output smoothing and/or electrical load shifting, and (3) used electric vehicle battery cost estimation. Estimates of the cost effectiveness could be positive if the energy storage system battery pack prices drop to $375/kWh or lower.