Wenn im Aufzug das Licht ausgeht

When the lights are going out in the elevator

What do a refrigerator and an elevator have in common? Correct, there is a light burning in both of them. Engineers of Messrs. Henning in Wierthe have developed a device that turns the light off in empty elevator cabs. The use of this technology would allow one nuclear power station to be dispensed with in Germany.


Proud to present the „Lightwatcher“ intended to save energy in elevator systems: Tim Ebeling (right), chief developer of Henning, and hardware developer Michael Brüggemann with the miniature seismograph and an energy efficiency table.


Vechelde-Wierthe. Refrigerators and elevators do have more in common as Tim Ebeling, head of the development department of the Henning branch in Wierthe, discloses. Because since March energy efficiency classes were introduced for household appliances similar to the ones used for elevator systems and ranging from A for economical up to G for wasteful. „Many elevator systems unfortunately belong to the energy-wasting class“, Ebeling says.


The elevator’s saving potential is enormous: „A normal passenger lift is in operation for maximum half an hour every day and is not used the rest of the day“, the 34-year old explains. Unlike refrigerators in which the light is turned off as soon as the door is closed, the lights of many elevators are permanently on stand-by. If one adds up the energy that is wasted by the lights of some 650,000 elevators in Germany, it is theoretically possibly to shut down one entire nuclear power station, the chief developer says.


The device developed by the engineers in Wierth is slightly smaller than a CD and fitted with a highly sensitive seismograph which registers minimum vibrations. The „Lightwatcher“ detects people in the cab as well as door and cab movements. As soon as it detects that the elevator is not being used, the light is turned off. Ebeling estimates the cost saving potential at some 300 Euros per year for an average of 1100 wasted kilowatt-hours per year and elevator.


According to Ebeling the patented device which costs about 100 Euros has been sold more than 2000 times to America, Australia, China and India. As a matter of fact the „Lightwatcher“ actually is a „by-productt“, Ebeling explains with a smile. Henning products such as safety sensors for giant elevator systems in high-rise buildings in Dubai are much more complex. The technology in the new device is rather simple and can be compared with that of a refrigerator.


Michael Lieb