Snow load solar modules guarantee earning power even under the highest loads
The snowmelt in springtime will bring a cruel awakening for many operators of solar plants in heavy snowfall regions. Then it becomes apparent how many of the photovoltaic roof systems did withstand last winter season. The heavy snowfalls in Germany, Austria and Switzerland have brought snow quantities of up to three meters to some regions. One cubic meter of dry powdery snow has a weight between 30 and 50 kilograms. A cubic meter of old snow can weigh ten times as much. The result can be pressure and suction loads of 500 kilograms per cubic meter and more.
The snow load suitability of solar modules is essential their resistance to high pressure and suction loads. As part of safety tests in accordance with IEC Standard 61730 of the International Electrotechnical Commission, solar modules are tested vertically for pressure and suction loads (Mechanical Load). While the modules of some manufacturers achieve a mechanical load of 2400 Pascal (equivalent to about 240 kilograms per square meter), higher-quality manufacturers achieve a mechanical load of 5,400 Pascal (equivalent to about 540 kilograms per square meter).
A further is to be seen in the possibility of slipping snow loads on pitched roofs. These can pull the solar cell laminate out of its frame and cause lasting damages to the solar module (see attached damage pattern).
However, even if a module has withstood the mechanical load, the bending of glass-foil modules causes microcracks in the cell. Depending on the fracture pattern, microcracks can adversely affect the performance of the modules. This risk does not exist with doubleglass modules. With doubleglass modules, a second glass sheet is used on the back of the module instead of the plastic film. Thus, the highly sensitive solar cells are embedded in a neutral zone so that no microcracks or power loss can occur in the event of bends.
Ideally in snowy regions, only snow load solar modules should be used. The snow load solar modules of the Sonnenstromfabrik offer the right kind of protection – the stability of the module is additionally ensured by a specially developed compound of the doubleglass laminate and the module frame. A special adhesive with extremely high bond strength is used. TÜV Rheinland has tested the 60-cell snow load modules up to a maximum test load of 825 kilograms per square meter (8100 Pascal) and confirmed the higher bond strength.
Do you have any questions about our snow load solar modules?
Then write to us at: sales@sonnenstromfabrik.com
