Transportation. But be careful to distinguish "work" from "primary energy". The latter is raw energy content of fuels, maybe 80% of which is wasted when powering (say) a car. Moving to BEVs would reduce total energy use because as much as 5 units of primary energy gets replaced by 1 unit of electrical energy.

A similar effect (if not as dramatic) occurs when replacing a fuel-burning furnace with a heat pump. In the US, 2/3rds of industrial heat demand is below 300 C and could be addressed with industrial heat pumps of various kinds (especially if the process has a waste heat stream to recycle by feeding it into the heat pump.)

If we’re being honest, I think we should probably also include raw chemicals that would otherwise be used for things like direct heating. So for example, crude oil used for making asphalt, plastic, etc. or natural gas used for fertilizer.

Since replacing them would consume energy too.

That is a less obvious piece of math, but if we’re talking carbon neutral it would matter doesn’t it?