As the key components of the solar collector, the evacuated tube is a product that is optimized in geometry and performance

The tubes are composed of two concentric glass tubes which in each case are half spherically closed on one side and fused together on the other side. The gap between the tubes is evacuated and afterwards hermetically plugged (vacuum insulation).

In order to make solar power usable, the internal glass tube is provided on its external surface with an environmentally friendly, highly selective layer and is thus designed as an absorber

This coating is thus protected within the vacuum gap. It is an aluminum nitrite sputter layer which is characterized by very low emission and very good absorption.