Vacuum Technology

Due to the atmospheric pressure and the technical problems related to the sealing of the collector casing, the construction of an evacuated flat-plate collector is extremely difficult. To overcome the enormous atmospheric pressure, many internal supports for the transparent cover pane must be introduced. However, the problems of an effective high vacuum system with reasonable production costs remain so far unsolved.
It is more feasible to apply and adapt the mature technology related to the lamp industries with proven mass production. Building a tubular evacuated solar collector and the maintenance of its high vacuum, similar to light bulbs and TV tubes, is practical. The ideal vacuum insulation of the tubular evacuated solar collector, obtained by means of a suitable exhausting process, has to be maintained during the life of the device to reduce the thermal losses through the internal gaseous atmosphere (convection losses).