Evacuated tube solar collectors

These hi-tech evacuated tubes are built by Ritter in Germany. The tubes are constructed like a thermos flask: the inner tube is has a black coating on the outer surface and the outer tube is transparent, with a vacuum between them. This means the inner surface can get very hot in the sun – up to 250°C!

Because of the vacuum, no heat is lost by convection. This means the array performs better under low light conditions and can reach very high temperatures. However, research at our test site has shown that the benefits of this approach are only significant when water is to be heated to high temperatures, such as 80ºC. When heating to 60ºC, as in the home, the flat plate panels offer as good if not better performance.

 

 

Picture gallery

Move your mouse over the list below to see the images:

View end-on

Close-up

Commercial site

 

Return to first image