Judging by the fact it's costing me less I'd say it is more efficient than my old oil heating system where I did not have individual room control. The conversion of electricity to heat is extremely efficient, close to 100%. If there were small heat pumps I could install per room I might consider that to increase efficiency, but all the ones I see for sale are big and high capacity and a pain to install myself (having to charge them with a gas). It would be great if there were smaller room scale units that just required a simple hole drilled to the outside and came pressurized with a simple snapfit connection to connect the two pressurized halves. Or maybe charging such a system with gas could be made simpler using a built in pressure regulator and reservoir. I looked into downhole heat exchangers and I can't afford to install one and even if I could it wouldn't pay itself off within my remaining lifetime. My house is already fairly well insulated.