What type of fuel is best?

Knowing I had to get a new heating idea for my home, I kept trying to figure out what type I wanted. I knew that I wanted something that was going to be energy efficient in fuel consumption in addition to in heating. My question was; what type of fuel would be to obtain this goal? The topic of fossil fuel was coming up all the time right now. Oil was the most apparent fossil fuel, but what about gas or coal. Coal was supposed to be a pollutant. Living in a coal region, the two of us were constantly being told that coal is the cleanest burning type of fuel you could use. I was brought up with a coal oil furnace for heating. The heat was constantly comfortable in our home. Mom had a self-feeding oil furnace in addition to he only had to fill the coal hopper once a day. People complained because they needed a room to store the coal, but you also need a storage bag for oil in addition to gas. Gas is the next big thing when it comes to heating. My concern with gas is that one of its big by-products is carbon monoxide. Carbon monoxide is a deadly gas that is tasteless, smellless, in addition to entirely white, in addition to you don’t even suppose you are being killed by it. Mom told me that nearly every type of fuel can cause carbon monoxide, so I was back to worrying again. Oil is supposedly the worst of the pollutants, but it is also one of the safest to use. I started thinking about electricity. I suppose that more than 2 people don’t want to use electricity for heating, because there are more than 2 variants that can knock out electricity. I just can’t make a decision on a source of heating.