In the mountainous Oppland County of Norway, parts of the 53 road run above the treeline and are affected by avalanches which result in the road network being closed for days on end. To overcome this, the Norwegian Public Road Administration (NPRA) selected the Wyssen Avalanche Tower to provide controlled mini avalanches that stop the build-up of snow that might cause a major avalanche.

The challenge is how to power the Wyssen equipment, mounted high up in the snow fields above the road. It’s a tough environment with:

• Strong winds
• Sub-zero temperatures
• Almost no daylight during the winter.

Powering the equipment off-grid required a special solution. Wyssen selected the Leading Edge LE-v150 Extreme wind turbine, a vertical turbine that can survive wind speeds of 45m/s (100mph) and sub-zero temperatures.

“There’s not enough solar irradiation at this latitude during the winter and traditional horizontal turbines weren’t an option, they just wouldn’t survive the harsh conditions” said Benjamin Meier, Chief engineer at Wyssen Avalanche Control.

Each of the 14 Wyssen Avalanche Towers is installed on a known avalanche path and an LE-v150 Extreme is mounted at the top of the 8m high tower, attached to the Wyssen magazine box containing prepared explosive charges. Detonation of the explosive charge is performed remotely and large enough to move the snowpack.

During the first 2 winter seasons, close to 200 avalanches have been released and the risk for road users significantly reduced.

The NPRA considers the project to be a great success, especially as the investment is much lower than traditional avalanche protection measures, such as building tunnels, dams, snow sheds or snow fences.