Solar Drainback Systems

Analyzing European Influence on American Solar Hot Water Systems

One good way for me to keep informed about the latest trends (good and bad) is by reading  SolarPro magazine.

Although the publication is typically dominated by PV articles and advertisements, occasionally I’ll find something of interest on solar thermal.

So I was certainly curious when I saw that the August/September 2011 issue had an interview with Ole Pilgaard, President of  Heliodyne . The article, entitled Ole Pilgaard, Heliodyne: Bringing European Experience to the US Solar Thermal Industry can be read in its entirety by clicking  here (free subscription required).

In the interview, Mr. Pilgaard discusses differences in history and philosophy between European solar thermal development and American.

He states for example,  “The European solar thermal industry developed faster in the northern countries, like Germany and Austria, where freeze protection is more of an issue than stagnation. Some malfunctioning drainback systems received bad publicity in Europe when solar thermal grew into the mainstream contractor business. As a result, it became more apparent that drainback systems are extremely sensitive to correct installation. The European solar thermal technology platform therefore developed in the direction of fully flooded glycol systems, which are more reliable than drainback systems and less sensitive to correct installation.”