Solar Water Heater

Solar water heater systems generally are more expensive to buy and install than usual electric or gas water heating systems. Nevertheless, by heating water using a solar heater you will save money over time. By choosing solar technology you expect savings between 50 to 80% on your heating bill. 
Collecting energy from the sun for heating water is not a new concept. It is known that since 1800 such systems using solar energy exist. Generating hot water using solar energy can be implemented almost everywhere and the only fuel needed is the sun.
The main components of a solar water heater system are the solar collectors that attract solar energy and the storage tank that will keep the water hot. Such basic system is called passive solar. When electric pumps or other mechanical or electric devices are used to force the water through the system, it becomes solar active. It is very important for the storage tank to be well insulated. The more insulation the more it will keep the water warm.

Two configurations are usually available: The first one use what is called a two-tank system where water is preheated before entering the gas or electric water heater. On the second system (one tank system) the same storage tank is used for solar and electric/gas water heater.

Solar collectors are available in different designs. The glazed flat-plate collector is the most common one for domestic use.  Most of them are made of a black and flat copper plate with tubes fixed to the plate. When the sun irradiates the black plate the heat obtained is transferred to the water present in the tubes. The copper plate and pipes are installed in an insulated flat rectangular box. The box is closed by one or two transparent covers. Insulation is needed to avoid heat loss it is an essential point on a solar water heater.

In general solar collectors are installed on the roof, but when such setup if not possible they can be located on the ground, for example in a corner of the garden, or even on the roof of a shed. In all cases it is important that the solar panel heaters face the south direction.

Each solar water heater has a different design and operating system. As the sun doesn’t shine all the time, you will often need a backup water heater running on gas or electricity for overcast days. Depending on your location, size and orientation of the collectors and solar water heater system choice, solar energy can provide most of your hot water needs.