The results are reported of energy- and exergy-based comparisons of coal-fi
red and nuclear electrical generating stations. Overall energy and exergy e
fficiencies, respectively, are 37% and 36% for the coal-fired process, and
30% and 30% for the nuclear process. Energy losses associated with emission
s (mainly with spent cooling water) account for all of the energy losses, w
hile emission-related exergy losses account for approximately 10% of the ex
ergy losses. The remaining exergy losses are associated with internal consu
mptions, mainly in components which generate heat by combustion or nuclear
reactions, and in components which transfer heat across large temperature d
ifferences.