Higher Consumption Rating means it consumes more power. But it also doesn't change in the description after you upgrade, and it's almost impossible to tell how much effect, if any, your upgrades have had. The biggest thing you can do to reduce your bills is enabling auto lights, because the Eco Living changes greatly exaggerate how much power a light uses, and there's no upgrade options on lights.
Also they seem to have forgotten to make hot tubs a huge energy hog. Ask anyone who has one in real life!