Limitations Solar water heating systems require regular maintenance, have a relatively high initial cost, and a long payback period, unless the cost of heating water is high. Solar panels may be aesthetically unacceptable to some. There is potential for freezing with passive systems. The Solar Ratings and Certification Corporation runs a certification program for solar water heating systems. There are a number of manufacturers of solar water heating systems.
Manufacturers can provide information on local dealers and installers.
Environmental Design Index Provides list of manufacturers, distributors, and retail sales of solar water heaters.