Thermal solar collectors
These collectors are used for heating water. The hot water is stored and can be used as hot tap water and/or for heating.
Tests in practice [Erhorn-Kluttig et al., 2011] show that thermal solar energy systems have been developed as far as possible. They work well and cost between €3,700 and €5,680. These prices include storage and a control system for a comprehensive package that covers approximately 60% of the heat required by a four-person household. [Erhorn-Kluttig et al., 2011]