What about freezes and cloudy weather?

Both active and passive solar water heating systems come with a 100% lifetime guarantee against freeze damage. The active and the passive solar water heating systems are both approved by the Florida Solar Energy Center for use in northern climates. Active solar systems have a conventional electric heating element to heat water on the few days that it might be needed. Passive solar systems act as a pre-heater to heat water before it is drawn into the cold inlet of the standard gas or electric water heater. All solar water heating systems deliver both higher temperature water and more water volume than conventional water heaters. Typically 40 to 80 gallons more hot water than conventional water heaters.