Imagine this: You head out for dinner at a popular new restaurant in a hip part of downtown on a Saturday night. Before you leave home, you know the fastest route there and where you’ll park.
Using data collected from sensors on the light fixture that’s been combined with your city’s other information systems, your car will “tell” you about construction areas to avoid, to valet park because the nearest garage is full and to not waste time driving around the block because there hasn’t been on-street parking for hours.
This scenario is closer to reality than most people think.
Equipped with computers and sensors that provide a real-time view of what’s going on, LED fixtures can become high-performing, low-cost communication networks. From parking and traffic—including cars, bicycles and pedestrians—to temperature, humidity, precipitation and ozone levels, they’ll provide the foundation for multiple infrastructure solutions.
Cities will save money because LED technology is more energy efficient than HPS, but also because they’ll pay only for the energy each light uses instead of a flat-rate tariff. Managers will be able to program when each light, or group of lights, turns on and off and at what intensity. They’ll see exactly what’s wrong with each light from their desktop, iPad®, and/or smartphone, so they can tell crews what replacement equipment to load into their truck.
Maximizing replacement capital
In less than a decade, approximately 100 million LED street lights will illuminate the world’s roads—one for each HPS fixture remaining—up from about 20 million today, Navigant Consulting reports. Control node shipments are forecast to grow from 1.3 million today to 6.8 million by 2023, with roadway lights making up the bulk of these shipments.
Since an LED fixture is basically a programmable computer board, cities are beginning to explore applications beyond street lighting that their replacement fixtures could provide.
Could they also be used to provide public Wi-Fi®, which would impact citizen satisfaction and digital equality?
Could they use the poles to establish wireless gas, electric and/or water metering?
The answer is yes, and here’s how.
Most LED fixtures use radio frequency (RF) mesh technology that conforms to IPv6 over Low Power Wireless Personal Area Networks (6LoWPAN) specifications to transmit bits of data to and from the fixture to a central computer that handles the data. In essence, the fixture’s controls create a low-power but reliable communications network that would be cost prohibitive if developed separately. With street lights usually placed 150 feet apart, the poles are the perfect platform for adding weather, ozone and other sensors that can feed data back to the central computer for analysis.
Also, every controller on every light fixture acts as a router to every other controller on every other light fixture. With this, a city can stretch out its network, allowing light posts to be 1,000 feet apart and still communicate with each other.
A city tells it to turn on, turn off, when and how much to dim—like having the street light illuminated 100 percent when it gets dark and gradually dim to 70 percent until 3 a.m. until it goes back up to full brightness at 5 a.m. for early commuters. A city can set up these types of dimming schedules on an individual light, or they can group them together in neighborhoods or districts. But the data required to do so is nowhere near what’s needed to stream video to a smartphone.
Many lighting vendors are embedding a GPS chip in the control node, so users know the location and performance of each fixture or groups of fixtures. Knowing the location of each light pole, cities can manage the assets more effectively, particularly when there are failures. They can route maintenance teams by plotting more efficient routes, and they can move from preventive to predictive maintenance.
Marrying the two technologies produces intelligent street lighting, a once-in-a-career opportunity to free funds for other infrastructure needs while creating a digital legacy.