Large businesses do. I bet in some places you could get grant/loan incentives to replace a PC fleet with these things.

Back in the Pentium-4 days, iirc I was able to get almost $250k in grants and $1.5M in subsidized loans to do accelerated refresh of a PC fleet and small datacenter, all through a utility's peak load reduction program.

I don't deny such things happen but it's illogical. If you have 20 people on desktops a small fraction of them will use more energy for microwaving lunch, making coffee or on air conditioning than they will save in aggregate on this nominal reduction in power draw.

20, yes, it’s a waste of time. At 2000, reducing power consumption by 30%, may yield $100k annually.

How is it nominal? The current MacPro (which most of the target market would already be using) has a power supply that is >1kW. It's insane that this this is faster than the existing MacPro with a tiny power draw in comparison.

Microwaving lunch: 2 minutes at 800W; desktop with monitor: 8 hours at 150W, that is 45 times higher. Similar for coffee, no simple math for AC. If you can reduce 150W to 80W, it is both significant and achievable - this is what my desktop usually draws.

You forget these things sit ~idle (or at browser load) 99% of the time. The magnitude of difference only expresses at peak consumption. Furthermore, what about the lost time/hassle for changeover plus embodied energy in throwing out the last system? It's insanity.

The average corporate PC device gets replaced every 39 months.

Acceleration of that cycle with a Mac replacement, which usually has a 50-60 month lifecycle, is a pretty significant savings.

If those are real figures that's a good point :) I think we're well in to pedantry now. Call a somnambulance :)

The "few people" who use those apps are the people Apple is selling these systems to.