Among the collectors offered by Greenonetec, Europe’s leading flat plate collector manufacturer, is a unit that can be mounted horizontally, as on a flat roof, to hide it from view – a favourite among owners of housing estates. In all, Greenonetec offers clients three types of large collectors, including double-glazed units, with outputs ranging from 3.5 kW to 9.5 kW.
Savosolar has a similar product range, offering both single- and double-glazed flat plate collectors. To reduce heat loss, the manufacturer has decided to place all collector connectors inside the insulated collector housing. In addition, it has designed a mounting system that allows two collectors to rest on the same support, reducing the time and expenses needed for their installation, Savosolar said.
The large, double-glazed flat plate collectors in the group performed well at 50 °C, providing yields in the range of their vacuum tube counterparts. Moreover, Savosolar (15DG) and Greenonetec (GK) actually outperformed the vacuum tube units produced by Akotec (Mega) and Viessmann (Vitosol), losing only to Ritter’s Aqua Plasma unit. But at 75 °C, the situation changes, with vacuum tube collectors offering much higher yields than double-glazed units.
Yield comparison of selected large prefab collectors. Source: Solar Keymark certificates
|Company||Country||Collector series||Range of gross area per collector panel [m2]||Collector type||Absorber type||Website|
|Akotec||Germany||Mega||12.99||heat-pipe vacuum tube||full-copper strips||https://www.akotec.eu/|
|DOMA||Austria||Flex Alu||3.5 to 14.6||single-glazed flat plate||laser welded Alu-copper fins||https://www.domasolar.com/|
|Gasokol||Austria||gevoSol||2.25 to 12||single-glazed flat plate||full copper strips||https://www.gasokol.at/|
|Gasokol||Austria||powerSol||5.46 to 13.59||double-glazed flat plate||full copper strips||https://www.gasokol.at/|
|Greenonetec||Austria||GK2002||5 to 10||single-glazed flat plate||https://www.greenonetec.com/|
|Greenonetec||Austria||GK3003||8 to 13||double-glazed flat plate||full-plate aluminium-copper||https://www.greenonetec.com/|
|Ritter XL||Germany||XL 19/49||4.94||u-pipe vacuum tube||aluminium absorber||https://www.ritter-xl-solar.de/|
|Savosolar||Finland||15 SG||15.96||single-glazed flat plate||Aluminium Multi Port Extrusion Profile||https://savosolar.com/|
|Savosolar||Finland||15 DG||15.96||double-glazed flat plate||Aluminium Multi Port Extrusion Profile||https://savosolar.com/|
|Solvis||Germany||Fera||5.61 to 8.4||single-glazed flat plate||full-plate aluminium-copper||https://www.solvis.de/|
|SST Solar||Austria||ECO||6 to 24||single-glazed flat plate||full copper absorber||https://www.sst-solar.com/|
|Viessmann||Germany||Vitosol 100-F XL||7.91 to 13.17||single-glazed flat plate||full-plate aluminium-copper||https://www.viessmann.de/|
|Viessmann||Germany||Vitosol 200-T SPX-5||5.05 to 10.3||heat-pipe vacuum tube||n/a||https://www.viessmann.de/|
This article was written by Jens Peter Meyer, clean energy journalist and co-author of the German Solar Thermal Year Book 2021: https://www.solarthermie-jahrbuch.de/