Assessment of energy storage viability for a PV power plant injecting during peak load time

Photovoltaic (PV) power plants are a form of renewable energy and their importance is increasing all around the world. In Brazil, the PV power plants connected to the grid are regulated through a credit compensation, in which the prosumer pays the difference between consumed and generated energy. Medium voltage consumers pay different prices for the energy consumed in peak load time and off-peak load time. This paper compares the return of investments of a PV plant without and with energy storage systems. This latter injects active power during peak load time. Results show that although the plant without storage presents lowest costs, the solution with batteries can be more profitable depending on the energy tariff and the equipment cost.