  A large portion of astronomy's carbon footprint stems from fossil fuels
supplying the power demand of astronomical observatories. Here, we explore
various isolated low-carbon power system setups for the newly planned Atacama
Large Aperture Submillimeter Telescope, and compare them to a business-as-usual
diesel power generated system. Technologies included in the designed systems
are photovoltaics, concentrated solar power, diesel generators, batteries, and
hydrogen storage. We adapt the electricity system optimization model highRES to
this case study and feed it with the telescope's projected energy demand, cost
assumptions for the year 2030 and site-specific capacity factors. Our results
show that the lowest-cost system with LCOEs of $116/MWh majorly uses
photovoltaics paired with batteries and fuel cells running on imported and
on-site produced green hydrogen. Some diesel generators run for backup. This
solution would reduce the telescope's power-side carbon footprint by 95%
compared to the business-as-usual case.
