Solar water heating

Hot water heated by the sun is used in many ways. One of the most popular uses is made in homes to provide hot domestic water, solar hot water also has industrial applications, e.g. to generate electricity Designs suitable for hot climates can be much simpler and cheaper, and can be considered an appropriate technology for such places.

In order to heat water using solar energy, a collector, often fastened to a roof or a wall facing the sun, heats the fluid that is either pumped or driven by natural convection through it. The collector could be made of a simple glass topped insulated box with a flat solar absorber made of sheet metal attached to copper pipes and painted black, or a set of metal tubes surrounded by an evacuated (near vacuum) glass cylinder.

For industrial uses, a parabolic mirror can concentrate sunlight on the tube. Heat is stored in a hot water storage tank. The volume of this tank needs to be larger with solar heating systems in order to allow for bad weather, and because the optimum final temperature for the solar collector is lower than a typical immersion or combustion heater. There are numerous solar hot water Queensland companies who can install a heating system for you in no time.

Solar hot water systems fall into two groups: passive (sometimes called "compact") and active (sometimes called "pumped") systems. Both typically include an external energy source (electric heating element or connection to a gas or fuel oil central heating system) that is activated when the water in the tank falls below a minimum temperature setting such as 55°C. Hence, hot water is always available.