An agile life cycle assessment for the deployment of photovoltaic energy systems in the built environment

Background

In the context of urban energy transition, photovoltaic (PV) systems play an important role in electricity generation. However, PV technology has some environmental drawbacks that also need to be acknowledged and managed. Life cycle assessment (LCA) is widely used to assess the environmental impacts of systems, but LCA is very complex to perform. Therefore, this research work presents a proof of concept for a parameterized LCA tool for grid-tied photovoltaic systems in urban areas that allows non-experts in LCA to obtain LCA results reliably and quickly.

Results

The resulting methodology is an integration of three preexisting tools: PVGIS, Brightway and Ecoinvent, plus a Breakeven point analysis. The first step of the approach consists of identifying the main parameters of photovoltaic systems: geographical, technological, and temporal. Once the non-expert practitioner sets the influential parameters, the tool assesses the greenhouse gas emissions over the life cycle of the PV panels per unit of supplied electricity, allocates the emissions per component, and calculates the point at which the avoided emissions compensate for those produced by the power system. The algorithm strives to find the optimal PV system configuration to reduce the environmental impact, providing decision-making support for promoters and policymakers in the context of the urban energy transition. Two case studies are presented to illustrate the proposed method’s applicability and benefits.

Conclusions

The production of PV panels was confirmed as the main source of emissions in this kind of installation. The reasons are analyzed, allowing for improved design. Furthermore, the estimated break-even point where savings of conventional electricity offset emissions shows the influence of the parameters on the system’s environmental performance.