Re:Activists who embrace nuclear power
by pfdietz on Tuesday February 23, 2021 @08:24AM
(#26236942)
It matters because it leads you to overestimate the energy needed. It does not take 1 J of renewable energh to replace 1 J of coal.
And it's not just the electricity sector where this matters. A battery vehicle uses much less energy that a gasoline vehicle, because the latter has maybe 25% average thermal efficiency (that varies with details, of course). It applies to any industrial process using anything below arc furnace level heat: heat can be generated by heat pumps (compress argon to the desired temperature, extract the heat, then expand the cooled argon maintaining its temperature with low grade waste heat to recover some of the work.)
About the only place it doesn't apply is if the electricity is used to make synfuels (aviation fuel, for example) or in chemical processes where the fossil fuels were used directly (hydrogen for ammonia synthesis).
And it's not just the electricity sector where this matters. A battery vehicle uses much less energy that a gasoline vehicle, because the latter has maybe 25% average thermal efficiency (that varies with details, of course). It applies to any industrial process using anything below arc furnace level heat: heat can be generated by heat pumps (compress argon to the desired temperature, extract the heat, then expand the cooled argon maintaining its temperature with low grade waste heat to recover some of the work.)
About the only place it doesn't apply is if the electricity is used to make synfuels (aviation fuel, for example) or in chemical processes where the fossil fuels were used directly (hydrogen for ammonia synthesis).