There are 3 major components to a solar system:

1.  Solar Collector

2.  Solar Storage Tank

3.  Controller Package

Solar Collectors

Solar Collectors capture the sun's energy and convert it to heat.  There are two types of solar collectors:  flat-plate and evacuated tube.  In general, flat-plate collectors are best suited for the southern United States and evacuated tube collectors provide the most efficiency in colder, northern climates. 

Evacuated tube solar collectors contain a liquid non-toxic anti-freeze solution sealed in a vacuum within each tube's inner core.  Since liquids in a vacuum boil at a lower temperature, the liquid inside the collector tubes very quickly reaches boiling temperature and creates steam.  The steam rises to the top of the collector tube and heats the copper end of each tube.  Anti-freeze solution is passed over the ends of the evacuated tubes and the heat from the ends of the tubes is transferred to the antifreeze solution. 

Solar Storage Tanks

The hot antifreeze solution is pumped from the solar collector to a Solar Storage Tank.   Solar Storage tanks have an interior coil of copper pipe which is used to hold the hot antifreeze solution.  This copper coil functions as a heat exchanger;  heat from the copper coil is transferred to the hot water in the tank.  The hot water is then used to fill our needs for domestic hot water, space heating, or pool heating.

Controller Package

The controller package includes a differential temperature controller, pump, and various valves and fittings.

The differential controller monitors the temperature of the anti-freeze solution in the solar collector and the temperature of the water in the solar storage tank.  When the temperature in the collector is higher than the temperature in the storage tank, the controller activates the system pump.  When  the reverse is true (temperature in the collector is cooler than temperature in storage tank), the controller shuts off the system pump.

The pump circulates non-toxic anti-freeze solution through the "solar loop":  piping that passes through the solar collectors, to the copper heat-exchange coil within the solar storage tank, and back to the solar collectors.