Peter Jones got it all wrong with the "dumb terminals" argument. For some reason the guy didn't explain himself terribly well. Dumb terminals may use less power but they also don't run any of todays software and severely lack in pretty much all areas. They are only really used these days in warehouses.
His PC's are just standard kit, off the shelf components. They run Windows. They aren't dumb terminals. Dumb terminals are from the 80s and early 90s.
The guy's crap comeback was to say "yeah but the KVM switching gear of a dumb terminal uses power". Erm ok

Surely he could have simply said "these run Windows and aren't dumb terminals. You can play games on them if you wanted. And yet they still use a fraction of the power that a regular PC uses."