Solar systems have no fuel cost and will rarely require maintenance.  While the cost of conventional water heating (natural gas, propane or electricity) will continue to rise, your solar system will continue to produce free hot water for 20 years or more.  If you are building a new home or refinancing your present home to do a major renovation, the economics are even more attractive.  The cost of a solar water heater in a new 30-year mortgage is usually between $13 and $20 per month. Solar power is affordable. 

Solar water heaters offer long-term benefits that go beyond simple economics.   In addition to having free hot water after the system has paid for itself in reduced utility bills, you and your family will be cushioned from future fuel shortages and price increases.  The National Remodelers Association reports that adding a solar water heater to a existing home raises the resale value of the home by the entire cost of the system.  You may be able to recoup your entire investment when the time comes to sell your home.

Many manufactured systems are available to the homeowner for solar domestic hot water, but the choice can be quite confusing if one is unfamiliar with the basic function of each type.  Before making the initial investment, it should be determined which system type would best serve your needs. 

A passive solar water heating system uses natural convection or household water pressure to circulate water through a solar collector to a storage tank or to the point of use. Active systems employ pumps and controllers to regulate and circulate water.  Although passive systems are generally less efficient than active systems, the passive approach is simple and economical.

A Batch Heater uses a storage tank as a collector.  The batch heater is the simplest of all solar hot water systems.  It’s simple design consists of a tank of water within a glass covered insulated enclosure carefully aimed at the sun.  Cold water, which normally goes to the bottom of your conventional water heater is detoured to the batch heater.  There it bakes all day long, and is preheated to whatever temperature the sun will provide.  Solar preheated water has become your cold-water input to the existing water heater.  Batch heaters are most appropriate for two to four person households (30-40 gal/day).  Their size is limited because the tank is built into the collector.

Thermosiphon systems are also passive systems that use gravity to power the convective flow of water in the system.  Water becomes buoyant as it is heated and rises into an elevated tank.  Cooler, heavier water falls from the tank to take its place.  Thermosiphon systems require no moving parts.  They are simple and elegant.

Active Solar Water heating systems use a circulator (pump) to move water to the collectors.  Active Solar Water heating systems use Flat Plate collectors.  Flat Plate collectors are the most common solar thermal collectors.  They are most appropriate for low temperature applications for domestic hot water and hydronic radiant space heating.  Flat Plate collectors usually consist of copper tubes fitted to a flat absorber plate, which is coated with a selective surface material that allows the maximum amount of available solar radiation to strike the collector and be converted into heat.  The selective surface allows a high absorbance of solar energy without re-radiating the long wave infrared heat back out.  Flat plate collectors are both highly efficient with a low profile for pleasing aesthetics.