I take it your electricity also is free of charge and you can use 12 hair dryers and vacuum cleaners all day.
There are countries in Europe where a household does need to pay for electricity.
Compared to my old machine, a Core2Quad Q9600, running an AMD graphics card, which was a 200-500 Watts light bulp, my current machine, a Core I5 7500 and an AMD Radeon RX 480, running idle and using 50 Watts.
Running EVE Online pushed that to 130 Watts or 185 Watts with Vulkan™.
In other words, I get much more processing power for a much cheaper electric bill.
How you would put efficiency into that comparison is up to you, I for one call that a fine piece of technology.