The WSL, a Swiss research institute focused on solutions for natural hazards, mountain ecosystems, and snow and ice, has studied the Bernina Pass. The study was conducted for a PV system design company planning to build a solar park in the area.
To assess the terrain, the WSL used a drone to measure snow depth. “Installing a photovoltaic system in a location with seven meters of snow in winter will undoubtedly result in damage by spring,” said Yves Bühler from WSL’s Alpine Remote Sensing research group.
WSL experts emphasised that minor location adjustments can determine the suitability of the terrain, highlighting the importance of drone-acquired scientific data.
“We use drone cameras to measure the spatial distribution of snow depths,” Bühler explained.
“By doing this after snowfall with different wind directions, we can better estimate suitable locations in terms of snow accumulation. Measuring both before and after facility construction is particularly beneficial.”
The aerial survey results are provided to planners to prepare expert reports and determine if special measures are necessary, said Stefan Margreth, head of WSL’s protective measures research group:
“Previously, we relied on rough maps showing average snow depth across Switzerland, sometimes supplemented by nearby measuring stations, which didn’t provide detailed information. In reality, even small depressions can result in significant local snow depths, making survey flights crucial.”
“You must adjust the ground clearance of PV modules to the local snow depth,” Margreth noted.
If the substructure is too low, the modules will be buried under snow, rendering the solar park non-functional and potentially causing damage due to snow pressure.
On an industrial building, a solar installation can increase the snow load by up to 25%; in open areas, this could mean around a 20% increase. Thus, a snow depth of 3 meters could rise to 3.5 to 4 meters.
Margreth also stressed the importance of monitoring snow depths after the system’s construction to provide a better basis for future solar parks and repairs.
Don’t miss Solar & Storage Live Zurich, taking place 17-18 September 2024.
