Spatiotemporal analysis of the future carbon footprint of solar electricity in the United States by a dynamic life cycle assessment

Abstract

Summary: Solar photovoltaics (PVs) installation would increase 20-fold by 2050; however, considerable greenhouse gas (GHG) emissions are generated during the cradle-to-gate production, with spatiotemporal variances depending on the grid emission. Thus, a dynamic life cycle assessment (LCA) model was developed to assess the accumulated PV panels with a heterogeneous carbon footprint if manufactured and installed in the United States. The state-level carbon footprint of solar electricity (CFEPV-avg) from 2022 to 2050 was estimated using several cradle-to-gate production scenarios to account for emissions stemming from electricity generated from solar PVs. The CFEPV-avg (min 0.032, max 0.051, weighted avg. 0.040 kg CO2-eq/kWh) in 2050 will be significantly lower than that of the comparison benchmark (min 0.047, max 0.068, weighted avg. 0.056 kg CO2-eq/kWh). The proposed dynamic LCA framework is promising for planning solar PV supply chains and, ultimately, the supply chain of an entire carbon-neutral energy system to maximize the environmental benefits.

Keywords

• energy sustainability
• environmental assessment
• global carbon cycle
• risk assessment