Lighting a Dark Spot on the Map

When the weather forecaster predicts a bright, sunny winter day, the citizens of Rattenberg know the only part of the report that applies to them is the temperature. The sun will not shine on their little town in the Tyrolean Alps.

“During the winter, it’s a fact that a large part of our town does not see the sun for two to three months,” says Mayor Franz Wurzenrainer.

Cold and depressing

From November to the beginning of February, the sun lies too low on the horizon and is hidden behind the Stadtberg mountain on the town’s southern side. Its rays never reach Rattenberg, which is cast in complete shadow. The neighboring village of Kramsach, however, enjoys the sun’s full radiance.

The situation isn’t much different in other small towns nestled in the narrow Alpine valleys, where residents frequently complain of the winter blues. But Rattenberg, the smallest town in Austria with just 440 people, could be the first to use modern technology to fight back against the natural circumstances.

A mirror trick

The Bartenback Light Laboratory in Aldrans near Innsbruck has come up with a solution to the dark winter days. Mirrors measuring 2.5 meters by 2.5 meters, so-called heliostats, could be erected on the opposite side of the valley to reflect the sun’s rays back towards Rattenberg. The mirrors would be computer programmed to adjust their direction according to the sun’s position and move automatically to maximize the full absorption of the light.

The mirrors may not light up the entire town in the same way as natural sunlight, but at least the residents will have some sense that the sun is shining, says Markus Peskoller from the Bartenback. He says that the residents of Rattenberg could of course also try to combat the winter depression by setting up artificial lights, but the mirror solution is considerably cheaper and cleaner for the environment.

Expensive sunshine

The project has one major drawback – namely its costs. Markus Peskoller estimates the total mirror set-up to cost about €2 million ($2.6 million). The town has already put in an application for EU development funding and the Austrian government in Vienna has also pledged money.

Mayor Wurzenrainer remains skeptical of the project. “It’s too expensive when you consider that the entire budget for Rattenberg is only €2 million.”