Financial and Environmental Life Cycle Assessment of Domestic PV-Battery Systems

This research evaluates the environmental and financial performance of domestic photovoltaic (PV) battery systems, particularly in light of the benefits and drawbacks of integrated lithium-ion batteries. The objective was to analyze whether the use of batteries in conjunction with solar PV is beneficial for both environmental sustainability and financial viability. The methodology involved developing a model that utilizes real-time measured solar generation and household load data, incorporating the impacts of battery degradation and lifespan. An innovative Emissions Arbitrage Algorithm was introduced to optimize battery operation scheduling based on time-varying grid CO2 emission intensities. Results indicate that a grid-connected urban home utilizing only a PV system achieves the best balance of sustainability and financial returns. Although adding a new battery becomes financially favorable by 2030, it decreases the environmental benefits compared to a PV-only system. Notably, second-life batteries outperform new ones in terms of environmental metrics, except for CO2 and fossil fuel depletion, highlighting the necessity of the Emissions Arbitrage Algorithm for operational efficiency. This study challenges prevailing assumptions in the literature regarding the efficacy of second-life battery applications in domestic settings.