With the increasing costs of energy and a desire for environmental friendliness, some customers are turning to the sun as a way to heat their domestic water. Bradford White manufactures a solar water heating storage tank for use with solar systems. This tank takes the heated water from the solar panels and uses it as a heat source instead of conventional gas, oil or electric heat sources unlike other tanks, this water heater has an electric heating element for back up on cloudy days, and when the solar system is not providing enough heat. However, it is important that you use only POTABLE (or domestic use) water in this tank.