You dropped the time component from the first, so yes, the result is incomparable.

“Power spent on lighting worstations while vacant” is energy

I don't think so, "while vacant" is an infinite amount of time, if you look infinitely far into the future.

Assume that each workstation is lit by 100W of lighting and is vacant 18 hours per day (to make the math easy).

I claim that's 75W of power that could be reclaimed by turning off a 100W load 75% of the time. Explain how you get to energy or how I dropped time, please.

2400 watt hours in a day, being reduced to 600 watt hours.

If you're not going to be charitable in interpreting comments, then perhaps this isn't the venue for you.

Uh... Watt-hours per day reduces to Watts in dimensional analysis, which is of course my original point.

The statement was rhetorical, not a precise engineering analysis.