How did you manage to consume 7KwH in just one day using only two computers? Heavy use of a laser printer?

That is 1000 watts continuous for seven hours, or 500 watts for 14 hours, roughly.

I have four huge screens (2x28" and 2x 32") plus a 15" MacBook and a bunch of router/WiFi/VOIP gear connected through a 1500 watt UPS, the total consumption is barely 400 watts running load.