Exploring configurations of a European energy system within the planetary boundaries

Abstract Planetary Boundaries and other carrying capacities define a safe operating space for humanity. However, current energy system models often address sustainability too narrowly with a focus on greenhouse gas emissions during the operational phase, and neglecting other environmental impacts can lead to suboptimal and unsustainable energy systems. This study integrates environmental impacts and planetary boundaries as constraints into a multi-sectoral energy system model to explore sustainable configurations for the European energy system in 2050. Our results indicate that it will not be possible to stay within all allocated carrying capacities without a combined application of energy demand reduction, large-scale deployment of renewable energies, electrification of heating, and technological improvements. Specifically, with the most permissive allocation principle, European electricity and heat demand must be limited to 3550 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:msub> <mml:mi>TWh</mml:mi> <mml:mi mathvariant="normal">e</mml:mi> </mml:msub> </mml:mrow> </mml:mrow> </mml:math> and 4655 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:msub> <mml:mi>TWh</mml:mi> <mml:mrow> <mml:mi>th</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:mrow> </mml:math> to remain within the planetary boundaries, which represents a 22% and 24% reduction compared to 2050 projected final energy demand for the sectors of electricity and heat, excluding transport and fuels demands. Results show that scenario normally considered ‘Net Zero’ would transgress the allocated budget for climate change by 70%, despite a high deployment of renewable energies, when life cycle impacts are considered. All generated scenarios highly rely on renewable energies and the electrification of heating. The analysis of the different scenarios highlights substantial burden shifts across carrying capacities when only considering climate change and praises a global environmental approach in decision-making. Climate change, land use and particulate matter are identified as the most impacted categories when designing an energy system.