The Solar Power Expert Blog

Solar Thermal Heating Systems

by Chris - November 21st, 2012.
Filed under: Guest Posts.

Solar thermal systems are systems that convert solar energy into useful heat. This heat is used in hot water systems for cooking, showers, laundry rooms, faucets and process heat in residential and commercial applications. These systems take solar radiation and convert it to heat by using solar thermal collectors, which then transfer that heat to the water.

How the technology works

Solar thermal collectors contain a small network of water tubesadjacentto solar panels. As the sun’s radiation is absorbed by solar panels, the water inside the tubes heat up. This hot water then flows through a solar controller and into an insulated storage tank where the water is kept hot. The job of the solar controller is to read the water temperature inside the storage tank and send more hot water if needed. The controller activates a pump that sends hot water from the solar collector tubes to the storage tank.

Solar thermal storage tanks

Solar storage tanks usually have 3 inches of foam insulation to keep the water relatively hot even if there is no sunlight for three days. Some storage tanks will use a heat exchanger to transfer heat from the hot water in the tubes to the water in the storage tank. To provide additional backup, some storage tanks have an electrical heating element to heat the water in case the solar system is not providing enough hot water.

Pros and Cons of solar thermal systems

The pros of solar thermal systems are many: they supply inexpensive or free water heating, they are environmentally friendly, they require little maintenance, they use a renewable source of energy, and they are up to 5 times more energy efficient than solar photovoltaic systems. They also cost significantly less than photovoltaic systems and are an easy and practical way to start using a renewable source of energy at home.

The major cons against solar thermal systems are that heating can become inconsistent due to seasonal variation of solar radiation, and they cost more than traditional gas-fired water heaters. Nevertheless, the cons are insignificant when compared to the pros, and solar thermal systems should be considered a practical solution for domestic water heating at home or commercially.

You can read more about solar systems and sustainability at

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