Techno-economic analysis of battery electricity storage towards self-sufficient buildings

Abstract

Effective electricity storage solutions that decouple energy use and production are central to the green energy transition. In particular, in the residential sector, the implementation of such solutions should boost the potential of nearly zero energy buildings to reduce the primary energy consumption and greenhouse gases emission and towards a greater energy self-sufficiency.The aim of this paper is to assess a climate independent scaling law for the introduction of a battery energy storage in a residential environment. To this end, we evaluate the environmental and economic impact of the integration of a lithium-ion battery in a real existing residential building, for different climates and for different battery capacities. The building is made of 13 apartments and features a reversible heat pump, a photovoltaic system, and a lithium-ion battery. We model all the elements and the energy consumption of the building and validate results against measured data.The results show that sizing the lithium-ion battery based on the variation of the self-consumed renewable energy yields a sustainable investment for all climates. Moreover, from a techno-economic perspective, lithium-ion batteries are better suited for daily energy storage rather than seasonal storage. In fact, they efficiently fill the time lag between demand and production on a daily time scale. On the other hand, lithium-ion battery costs gathers unsustainable investments for seasonal storage also considering any foreseeable battery cost reduction. Optimized building-level battery storage cannot fill completely the temporal mismatch between production and usage. As a consequence, different technologies (e.g. electric mobility) should be also considered to locally consume all the energy produced by the photovoltaic.