Characteristics: Bismuth is a brittle, silvery-green metal that has a low melting temperature and high specific gravity. Being both stable and non-toxic, bismuth is often used as a replacement for toxic metals such as antimony, cadmium, lead and mercury.
1 (Minimums vary by location and tank size, and can range from 100-1,500 gallons.) More often, the propane company charges a fee of anywhere from $25-$250 a year but averaging around $75-$130 annually, depending on local rates, the size of the tank and whether it's aboveground or underground.
Assuming average usage and $0.086/kilowatt hour in electricity costs, your electric tank will cost around $400 to operate per year. Assuming $0.50/therm gas cost and average usage, your gas tank will cost you around $120-130 to operate per year.