Solar Thermal Technology
Solar thermal systems
Solar thermal systems collect solar radiation and transfer it to a fluid in the form of thermal energy. The available solar thermal systems up to now are the following.
Diana - Thermal Solar Systems
The solar thermosiphon is the most commonly used system for hot water production. It consists of the solar collectors, the hot water tank and the pipes. The collectors absorb the solar radiation and the heat is physically driven to the hot water tank that it is placed always on top of the collector. There is no electricity consumption.
In central domestic hot water systems, the water tank can be placed anywhere in the building (i.e. basement) and the collectors can be fully integrated in the roof tiles. The water is circulated via pumps and electronic controls that consume a small amount of electricity; the aesthetic result however is flawless.
Central Combi systems can cover the 10-60% of the hot water and space heating needs, depending on the system characteristics, the climate and the type of building.
Combi systems consist of the collectors, the water tank and a electronic control. They usually require a conventional back-up system (i.e. gas boiler) to provide the necessary heat during long cloudy periods.
Combi systems are ideally combined with low temperature heating elements such as fan coils and underfloor heating.
Combi plus systems are similar to Combi, with the addition of space cooling that is accomplished with a chiller.
The components of a Combi plus system are the collectors, the water tank, the chiller and an electronic control. The thermally driven chiller uses the water produced by the collectors, at a temperature of 70-100 οC, and produces chilled water at a temperature 7-10 οC. It consumes a minimum amount of electircity.
While the conventional air conditioning consumes huge amounts of electricity, the solar cooling consumes thermal energy that is generously provided from the sun.
A very strong advantage of solar cooling is the coincidence of high solar radiation with the cooling demands