Life cycle assessment of a virtual power plant: Evaluating the environmental performance of a system utilising solar photovoltaic generation and batteries

Abstract

As the world shifts to renewable energy sources to mitigate climate change, virtual power plants (VPPs) have emerged as an innovative solution for integrating distributed renewable generation. This study conducted a comprehensive Life Cycle Assessment (LCA) for a 40 MW VPP in operation in Aotearoa New Zealand, comprising residential solar photovoltaic systems with battery storage. Unlike traditional LCA studies that focus on individual components, this study evaluates the full life cycle impacts of a VPP, offering a holistic view of its environmental implications. Additionally, the study considered electricity fed back to the grid, which avoids grid electricity, or electricity generation from natural gas. The findings reveal an estimated life cycle greenhouse gas (GHG) emissions of 45.3–78.9 gCO2eq/kWh for the VPP, depending on what the surplus electricity replaces. Notably, avoiding natural gas electricity generation by returning surplus electricity to the grid yields a significant credit of −47.3 gCO2eq/kWh. The life cycle GHG emissions of the VPP are highly sensitive to PV generation. If the systems are operated at their maximum potential, the overall emissions reduce by 17.6%. Conversely, when operated at minimum potential, the emissions increase by 23.2%. Additionally, uncertainties in the energy demand to manufacture the battery cells can alter GHG emissions from a 6.7% reduction to a 14.3% increase. This study underscores the complexity of evaluating environmental performances of VPPs and fills a gap in the literature by presenting the potential environmental impacts and benefits of VPPs, shedding light on their role in fostering sustainability with the energy transition.