Volker Kallwellis, head of development department at Wagner & Co Solartechnik, Cölbe, Germany published the following statement in the international magazine Sun & Wind Energy 7/2009 about the advantages of […]
Marek Szymanski, technical department manager of the Polish collector manufacturer Watt, spoke with solarthermalworld.org about the problems they had with the vacuum tube collectors in the beginning. Photo: Watt