Whole life carbon of photovoltaic installations

Summary

This study investigates the embodied and operational carbon impact of roof mounted solar photovoltaic (PV) installations. It includes an in-depth assessment of the embodied carbon of PV systems and frames a discussion on the most relevant metric for making decisions on the installation of PV.

Photovoltaic (PV) is an important source of renewable energy generation, and rooftop solar can contribute a significant part of the government roadmap to meet UK climate targets. This paper explores the interplay between embodied carbon impact and the operational carbon savings for various roof mounted PV system installations.

This study concludes that a ‘payback’ approach for PV installations (i.e. embodied carbon impact compensated by the operational carbon savings) is not the right metric while we are in midst of an energy transition towards 100% renewables. Embodied carbon will have to be invested to achieve full grid decarbonisation and rooftop solar PV should continue to play a vital role in supporting this transition. Nevertheless, the study found that the embodied carbon to be between 520 – 780 kgCO2e/ kWp, which is less than the operational carbon savings over a 25-year study period based on a UK grid. The study concludes that rooftop solar PV can
represent a valuable investment of embodied carbon, but that built environment professionals should employ detailed embodied carbon assessments to ensure that impacts are minimised through intelligent design and specification decisions on a project-by-project basis.