With an increasing share of renewable energy technologies in our energy systems, the integration of not only direct emission (from the use phase), but also the total life cycle emissions (including emissions during resource extraction, production, etc.) becomes more important in order to draw meaningful conclusions from Energy Systems Analysis (ESA). While the benefit of integrating Life Cycle Assessment (LCA) into ESA is acknowledged, methodologically sound integration lacks resonance in practice, partly because the dimension of the implications is not yet fully understood. This study proposes an easy-to-implement procedure for the integration of LCA results in ESA based on existing theoretical approaches. The need for a methodologically sound integration, including the avoidance of double counting of emissions, is demonstrated on the use case of Passivated Emitter and Rear Cell photovoltaic technology. The difference in Global Warming Potential of 19% between direct and LCA based emissions shows the significance for the integration of the total emissions into energy systems analysis and the potential double counting of 75% of the life cycle emissions for the use case supports the need for avoidance of double counting.

The German Federal Climate Change Act includes binding annual greenhouse gas (GHG) emission targets for the economic sectors energy, industry, buildings, transport, agriculture and waste. For sectors that fail to meet their targets, climate policy measures have to be implemented immediately. However, some sectors may only have achieved their targets thanks to the COVID-19 pandemic, while others may have missed their targets because of COVID-19. For policy making, it is therefore important to disentangle the effects of the COVID-19 pandemic from the effects of policy and other drivers on emissions. In this paper, the effects of the pandemic on GHG emissions in Germany in 2020 are estimated at the national level and at the levels of the economic sectors. Counterfactual emissions are estimated here based on autoregressive econometric models, thereby distinguishing between different factors of emissions based on decomposition analysis. The findings at the national level suggest that the COVID-19 pandemic lowered GHG emissions in 2020 in Germany by about 41 Mt CO₂-eq (5.15%) compared to counterfactual emissions. Accordingly, about 58% of the reduction in emissions between 2019 and 2020 in Germany may be attributed to the pandemic. The findings at the sectoral level imply that without the COVID-19 pandemic, all sectors with the exception of the transport sector, would have met their emissions target in 2020 as set in the Federal Climate Change Act. The transport sector would have missed its emission target in 2020 without COVID-19, suggesting that existing policies were not strong enough to bend the curve of emissions trends sufficiently down. In contrast, the buildings sector failed to meet its target in 2020 because of COVID-19, prompting immediate climate policy measures in this sector. Key policy insights