Let's see....I've thought about geothermal but we only use about 200 gallons of oil per year as it is right now, and I've added a propane auxiliary heater, actually bought for emergency use, that keeps the house at 70 even when it's in the 20's outside, with two dollars worth of propane per day. I estimate that costs less than half what oil would to keep the house warm. We use the oil at night for a few hours and again in the morning to pre-heat the house before we get up. I'm not sure how low our oil consumption will be using the propane heater. Incidentally, propane and CNG should be dropping as more fracking is done.
The propane heater uses 1.5 pound cylinders, and being cheap, I have rigged up a way to refill them, safely, so the cost of refilling/running the heater is as low as I can make it. I also have a regulator and hose set (25') with a quick connect that fits the heater so I can run off a 20lb tank if I want to. No refilling cylinders that way, but I'd need to keep the tank out on the deck, not in the house LOL, which means a door being open slightly for the hose and then being weather stripped.
I've also been thinking about adding a solar pre-heater for our water heating needs. The back of the house faces almost due south, so building a couple of panels and setting up a storage tank and pump system wouldn't be all that hard or expensive to do. I would also have to add a heat exchange tank, but again, no big deal.
When I mentioned that .28 to .05 comparison, those figures were based on a system that would supply one half of the average power requirements of a single family home. The base cost of the system was calculated at $45,000.00. Now I know I could get all kinds of subsidies and grants, but the actual cost is still there and it only supplies half of the power demand. If I had unlimited funds, maybe I'd do it, but in terms of an investment and practicality, it just isn't a very good one at all.
I've also though about wind turbines. I fooled around years ago building my own anemometer and it's an easy thing to do. A wind turbine is basically the same thing on a larger scale and the commercially available ones today look quite interesting. There is a newer design that uses a turbine style blade system rather than a propeller style. That should be quieter and simpler, it doesn't need to rotate to stay oriented to the wind direction. The thing putting me off is the relatively low output, a large one is only around 2KW, and given that it is wind dependent, I doubt it would actually achieve 1KW under the conditions here. Of course it still requires a pile of batteries and a real sine wave inverter to be useable.
I also keep thinking about adding a wood/coal fired furnace. In my case I would remote it in a shed away from the house, keeps the homeowners insurance from going up, and either pipe in hot air or hot water for heating purposes. The thing holding me back is a dependable supply of wood. I love cutting and splitting wood, great exercise and a way to get rid of frustration as well, but finding a cheap and dependable supply is a big problem. I may be able to get a cheap permit to cut wood in a State forest a few miles down Route 206, but I haven't looked into that, yet.
All of this is based on me being cheap. I really don't care if I'm on or off the grid. I like to be warm, have lights and AC. As far as climate change goes, I have to question the whole thing. It's based on research by the Hadley group in England looking at tree rings from Siberia. Problem is their whole hypothesis is based on the rings of one particular tree, out of thousands. That was the only one that matched their theory, the balance all denied it. Funny how they never mentioned that until someone started checking.