Solar collectors can be purchased, which consist of vacuum tubes made of thin (1.4mm - 2mm) borosilicate glass. Almost all vacuum tube plants are located in China, where this type of solar collectors are the most common. However, the impact resistance of such vacuum tube solar collectors is insufficient for the Latvian climate, where there are regular storms.
They break tree branches and lift various objects into the air, which can damage them when they hit the vacuum tubes. Hail grains in Latvia also tend to reach dangerous sizes for vacuum tubes.
For tubular solar collectors, no reputable testing laboratory in Europe issues certificates of conformity, as these solar collectors cannot withstand the stringent impact resistance requirements.
Another disadvantage of vacuum tube solar collectors is related to the typical Latvian winter. In winter in Latvia the temperature is often around and below 0o C. Snow enters between the vacuum tubes of the solar collector, but when the frost returns, the frozen snow expands and can break the tube made of thin (1.4mm - 2mm) glass. Another disadvantage of vacuum tube solar collectors is their lower efficiency in summer, when the sun's intensity is highest. Also, the design of tubular solar collectors is different from the classic and rarely fits into the architecture of buildings.