The energetic implications of introducing lithium-ion batteries into distributed photovoltaic systems

Journal article, 2019

Batteries for stationary applications can prove to be crucial for enabling high penetration of solar energy, but production and use of batteries comes with an energetic cost. This study quantifies how adding a lithium-ion (Liion) battery affects the energetic performance of a typical residential photovoltaic (PV) system for a wide range of climatic conditions. If all generated power is either self-consumed or made available via the existing distribution grid, the PV system has an energy return on investment (EROI) of between 14 (Alaska) and 27 (Arizona). While adding a 12 kWh Li-ion battery increases self-consumption considerably, this has the negative effect of decreasing the EROI by more than 20%. In a situation where all excess power generation is curtailed, the EROI can be as low as 7 (Alaska and Washington), although it can also be as high as 15 (Florida). Introducing a battery increases EROI but is still considerably lower than in cases where use excess power generation is added to the grid. Doubling the battery size increases the average self-consumption marginally, but further decreases EROI of the system because the extra energy invested to build the additonal battery is used inefficienctly. The results show that installing PV systems in locations with good solar resources and a grid that can accept excess prodution is desirable for maximizing net energy return from distributed PV. Batteries have a benefit when excess electricity generation can not be fed into the grid. Oversizing batteries has the effect of significantly reducing the EROI of the PV system.