What is the difference between the Siemens solar panels and (vacuum) tubes?
Panels similar to the Siemens solar panels (flat plate collectors) in Malta are the right panels to use for our climatic conditions and there are specific reasons for this. We have to find a balance between adequate heating in winter and avoiding overheating in summer. If a solar water heater using flat plate collectors is sized correctly (depending on the number of users and their consumption pattern) then the user will be supplied with an adequate supply of hot water. The difference in design is mainly due to the insulation used from one type of solar panel to another; Siemens (flat plate collector) uses polyurethane to insulate their panels whereas the vacuum tubes will use the vacuum itself (thermos effect) to insulate the tubes. The problems start when the vacuum tubes keep collecting heat in summer without being able to lose that heat – until the heat in the boiler goes over 100 degrees Celsius. The first thing that will happen is that the vacuum tube boiler might not be able to
