Differences in CO2 emissions of solar PV production among technologies and regions: Application to China, EU and USA

A widespread implicit assumption is that renewable energy options are approximately low-carbon. However, production and life cycles of such technologies tend to produce CO2 emissions. To minimize life-cycle emissions, one should account for such emissions and implement adequate policies to encourage innovation and adoption of well-performing technologies in this respect. We develop a framework to analyse this issue, grounded in the concepts of ‘energy return on energy invested’ (EROI) and ‘net energy return on carbon invested’ (EROC). Applying these to the main PV technologies and production regions – namely China, EU and USA – displays considerable discrepancies. We conditionally predict the development of average EROI and EROC over time under business-as-usual and low-carbon electricity generation scenarios. A main policy lesson is that without a systemic policy instrument, such as carbon pricing, incentives for low-carbon production of renewable energy options are too weak, which likely will delay a complete transition to a low-carbon economy.