I certainly don't advocate heating homes with oil but if you already live in a home which burns oil why not do it for free? There are millions of old oil tanks which need to be removed and people pay for this service. Where I live it's $150 per tank. Most tanks, will have some oil in them. When using old oil it's best to run a two tank system so the first one can be used as a settling tank. You're going to suck up all sorts of crud along with your oil. There will be quite a bit of buildup of sludge in tank number one which needs to be removed every few years. I have kept three homes in oil for 15 years doing this on a part time basis. You'll need a good pump, pickup truck, barrels and a grinder with cutting wheels so that you can process the old tanks. You need a mask, goggles, earplugs and good gloves.
Don't hire anyone extremely stupid to help you with this enterprise since oil spills are far more expensive than any money you may earn or save while doing this Now go to my post in green building titled "free metal fasteners for your post and beam building" to learn some of the neat things you can make with the heavy sheet metal from these tanks.