On 28 August 1980, a solar-powered emergency telephone is put into operation on the Bundesstraße 14 - the first large-scale test for solar power supply in the low-voltage range. This was preceded by years of laboratory tests. We thus made an important contribution to the development of low-voltage solar systems. Unfortunately, the trial could not be continued because the costs were too high. It was not until the year 2000 that the costs of a solar system fell to such an extent that some of the emergency telephones could be supplied with solar systems from then on.

first-emergency-telephone-with-solar-power-supply