Of the many electronics we build at my job, one of them is a shoe box sized 5kW power supply that we sell to the railroads. Testing 10 of these units in one afternoon, by one tech in a closet sized room, uses more energy than my house uses in a month (yes, it can get very hot in that room, hah)
And this is a very tiny project that's simply just easy recurring revenue. The bigger units that are being built and tested all day everyday will go through 100kWh just warning up.
It puts things into perspective were I can bend over backwards at home to save energy, but at work if I order a unit to be retested "just to be sure", it can wipe out months of energy I saved at home by being especially conscientious.
Not saying it's a waste to be efficient at home, I do it myself. But man, industry uses _a lot_ of energy, and it's not clear how to make it more efficient. I can't test a 25kW supply without running it at...25kW.