Stadtwerke Lemgo's new "dial4light" technology lets residents use mobile phones to turn on streetlights only as needed
At the beginning of the Harry Potter series, the wizard Albus Dumbledore uses a magical "put-outer" to extinguish the streetlights in young Harry's neighborhood. Now the municipal power company in Lemgo, Germany, is using a reversal of that idea to create a potential global business.
Stadtwerke Lemgo, which provides electricity and other services to the city of Lemgo in north-central Germany and the surrounding area, is looking for partners to help it sell a locally developed technology called dial4light. The system lets residents use their mobile phones to turn on streetlights, which means the city can leave them off the rest of the time and save money and energy. "We're doing something for the environment and the budget," says Friedrich Ehlert, mayor of D?rentrup, a town of 9,000 near Lemgo that was first to test dial4light.
The idea came from Dieter Grote, an advertising executive who lives in D?rentrup. Back in 2006, Grote was worried about the safety of his children after the town began switching off streetlights at night to save money. Around the same time, Grote, whose specialty is advertising for the lighting industry, happened to visit a public-services exhibit in Lemgo. While walking through the display, he noticed an old electricity meter that could be turned on and off according to need. "And that was the moment of inspiration," Grote recalls. "Why shouldn't it be possible to turn on and off streetlights like the lights in your living room?"
Numbers on the Lampposts
Grote approached Stadtwerke Lemgo with the idea. Managers of the taxpayer-owned utility liked it and enlisted help from A&H Meyer, a D?rentrup company that makes lighting equipment. The system they invented works like this: A resident dials a number posted on a lamppost. The call goes to a computer at the power company. The caller taps in a code number, also posted on the lamppost, which prompts the computer to send a signal back to a wireless modem that switches on the lights in that area. The whole process takes two seconds.
The system is ideal for a place like D?rentrup, a quiet community with a convenience store, a few pubs, and not much else. Before the system was installed on selected streets, the town turned off streetlights at 11 p.m. and back on again at 6 a.m. (Sensors automatically shut off the lamps during daylight hours.) After D?rentrup started using dial4light, the city could turn off lights on some streets at 9 p.m. And during the summer months it's often not necessary to turn them on at all. Mayor Ehlert says the city expects to save about $14,000 annually as it deploys dial4light town-wide. That's a third of the power bill for streetlights.
After news reports about dial4light began appearing, the city of D?rentrup and Stadtwerke Lemgo were besieged with inquiries from other municipalities interested in smart infrastucture. Municipal utilities aren't usually known as startup incubators. But managers at Stadtwerke Lemgo realized they might have a marketable product on their hand and applied for patents. Now the utility is negotiating with potential partners who will market dial4light abroad.
Dial4light works best in areas where there is little activity at night. If residents are turning on the lights more than three times per night, the lamps draw more power warming up than if they were simply left on. That, plus additional wear and tear on the light bulbs cancels out the cost savings. "It makes sense to turn off the lights where no one needs them, in very infrequently used areas," says Frank Br?uer, Stadtwerke Lemgo's project manager. "In little towns like D?rentrup, after 11 there is really nothing happening."
Recession Money Saver
The system also tracks usage, so cities can adjust lighting times if, for example, a group of lights is frequently turned on before midnight but not at all afterward. But why not just install switches on lampposts or use motion detectors? Br?uer points out that hand-operated switches are susceptible to pranksters. With dial4light, users register once online for the privilege of using the service, which is free. Motion detectors, meanwhile, are too easily activated by waving tree branches or passing hedgehogs, Br?uer argues. And with dial4light, one switch can be used to control a string of 10 or 20 street lamps, yet can be turned on by a single call from anywhere in the neighborhood.
Stadtwerke Lemgo has just begun speaking to potential partners, so it's not yet clear whether dial4light will shine in the marketplace. Says adman Grote, who will get a cut of the profits: "Even in a recession, a good business idea sells."