The solar water heater uses the energy of the sun in order to heat water. A solar water heater comprises a collector that absorbs sunlight and converts it into heat, and a storage tank that stores the hot water for later use.

In general, there are two types of solar water heaters: passive and active. In passive systems, water circulates by natural convection, whereas in active systems, the water is moved by a pump.

It is environmentally friendly to use solar water heaters and they can reduce energy costs significantly. The solar water heaters are particularly effective in sunny areas, where they can provide up to 80% of the hot water required for a household.

There is, however, a possibility that solar water heaters are not appropriate for all climates or households, as they require a certain amount of direct sunlight and may perform less efficiently in colder temperatures. Considering factors such as climate, local regulations, and upfront costs is essential when deciding whether a solar water heater is appropriate for your home.