This paper addresses the techno-economic viability of rooftop PV systems with batteries in Brazil for low voltage prosumers under net metering. Besides the traditional metrics NPV and LCOE, two additional indices adequate for battery systems are considered: the LCOS that measures cost, and the LVOS – Levelized Value of Storage, defined in this paper to assess the value that storage adds to a PV system. The study is conducted in software SAM of NREL, which allows to simulate systems performance over their lifetime and include the effect of equipment and parts replacement, degradation, and other operational aspects. Systems under net metering and TOU tariffs located in two Brazilian state capitals, one with very good solar radiation and high energy tariffs and the other with worse conditions, are assessed. Results suggest that the inclusion of storage can provide acceptable returns over investment only when justified by technical reasons.
Keywords Distributed PV generation plus batteries, Techno-economic assessment of battery systems, Levelized value of battery storage, PV plus battery under net metering