Energy System Pathways with Low Environmental Impacts and Limited Costs: Minimizing Climate Change Impacts Produces Environmental Cobenefits and Challenges in Toxicity and Metal Depletion Categories

Environmental
indicators based on the life cycle assessment method
are integrated into an energy system model. This integration allows
for the generation of comprehensive environmental assessments of future
energy systems and for determining energy scenarios with less environmental
impacts and moderate cost increases. In Switzerland, which is used
as a case study to demonstrate the feasibility of our approach, it
is possible to generate pathways with a 5% cost increase on the cost-optimal
situation, causing an impact score for climate change that is 2% higher
than the minimum feasible solution. The minimization of life-cycle
impacts on climate change generates substantial environmental cobenefits
with regard to human health, air pollution, ozone depletion, acidification,
and land transformation. However, this minimization also creates trade-offs
that exacerbate the effects of metal depletion and human toxicity
caused by upstream extraction and manufacturing linked to technologies
such as solar panels and electric vehicles. Finally, ambitious reduction
targets of 95% direct (i.e., within the country) CO2 emissions
for the year 2050 might still result in substantial climate change
impacts should emissions embodied in the infrastructure and upstream
supply chain not be jointly mitigated jointly.