We just got our first electric bill and heating the house during January and February which are traditionally our worst winter months only cost us $657.40 - or $328.70 a month. I can't believe it!!!!!! I am very pleased as mine is not an air tight well insulated, modern house. In fact, it is a leaky antique house with unknown insulation values and in serious need of re-caulking. I had been wondering what our cost was going to be now that we have an all electric system and have been anxiously awaiting our first bill. Especially because my husband has been quite sceptical about getting an expensive geothermal system which he was certain wouldn't work and/or would cost a fortune to run. He's astonished, in a good way, although he won't admit to it yet. Our oil bills had been running between $4499 and $5721 annually for heat and hot water (no a/c) using our inefficent old hot air furnace which was put in in 1984. We switched over to geothermal just after Jan 1st, 2010 after skating by the fall and early winter on a loaner high efficency propane gas H/A furnace courtesy of our wonderful geo installer, as our oil furnace had been red tagged last spring. I have been thrilled with the warmth and comfort of the new geothermal system - husband notices it too, but was concerned it might be expensive to run because my house is 170 years old and has lots of places for cold air to come in - like from under the baseboards in my kid's rooms which can get drafty in an east wind. I have been keeping an eye on the thermostat which is set at 70º. I've noticed the system usually runs in stage 1, rarely upping to stage 2 and has only used the auxillary coils when the system was first turned on and the house had been without heat for the day while the installation was going in. I hoped from that that our bill would be reasonable, but wasn't sure. Now, I know and it's a good feeling. I hope that people with leaky older houses like mine ignore all the naysayers who tell them not to go with geothermal, look hard to find a good installer (follow the steps posted at the top of the forum) and put one in. They won't regret it!