Guest Post: Heating Water with Solar Thermal Energy Systems

Solar thermal energy systems are used to harvest energy from the sun to use for heating water. Radiation from the sun is absorbed by the water through the use of solar collectors. Solar thermal systems are used in commercial and residential applications, where they are used for hot water supply in bathrooms, laundries, kitchens and process heating applications.

The Solar Collector: The solar collector is comprised of solar cells with water tubes underneath, that are used to absorb the sun's heat into the water. The water is warmed through the collector, flows through a solar controller, and into an insulated storage tank for future use.

The Solar Controller: The solar controller’s job is to measure the temperature of the water after the collector area and inside the storage tank. If the water temperature inside the storage tank is low, the controller sends a signal to a pump to turn it on. The pump then circulates hot water from the collectors into the storage tank.

The Storage Tank: The storage tank in has two to three inches of foam insulation surrounding it. This foam insulation can keep the water inside the tank at a high temperature for up to three days without requiring additional solar energy. For added back-up, some storage tanks incorporate an electrical heating element that can heat the water if the sun’s energy is not available due to cloudy conditions.

Advantages of Solar Thermal Energy: Solar thermal water heating costs close to nothing to operate once the system is installed. It is environmentally friendly, requires virtually no maintenance, and is four to five times more energy efficient than solar photovoltaic systems at a fraction of the cost for installation. Having a solar thermal energy system with a backup electrical heating element means you will never have to worry about
having hot water available.

Mauro Small writes for Go Green Academy, an information website on topics related to energy efficiency, climate change and sustainability.