Effect of Energy Storage on Self-Consumption and Self-Sufficiency: A Field Study in a Nordic Climate

Paper in proceeding, 2021

This paper examines the variation in self-consumption and self-sufficiency for eight residential-size solar photovoltaic systems under Nordic climate conditions. The work uses measured photovoltaic array performances with a 30-second temporal resolution and is evaluated for a full year’s operation. One of the systems is operated with battery storage to examine the effect on the system’s self-consumption and self-sufficiency, where the simulated load profile is taken from a single-family residential building in Sweden. The results show a consistent negative correlation between array size and self-consumption. The relation between array size and self-sufficiency is more sensitive and is also affected by the mix of PV technologies represented in the test. Adding battery storage increases the self-consumption in the range of 0-30 percentage points weekly. Furthermore, the variation of self-consumption and self-sufficiency follow the seasonal variation in solar resource and load size and illustrate the battery’s eventual redundancy in the winter when the battery’s objective function is to maximize self-consumption.