Sensor networks are getting a lot of play in the technosphere these days, and for good reason. Miniaturization, high throughput, and cheap data storage now make it both possible and cost-effective to install sensors throughout public and professional spaces. Sensors can collect data about human activity—the flow of foot traffic, usage patterns, preferences; the environment—daylight levels, temperature, humidity, the presence of chemicals or other dangers; and things—the locations of items in a warehouse, traffic patterns.
Connected lighting systems are uniquely positioned to serve as platforms for sensor networks. Lighting is already installed everywhere that people go, indoors and—at least in urban and residential environments—outdoors as well. Power is already available everywhere that lighting is installed. And connected luminaires already have the ability to send data “upstream” to IT networks. By integrating sensors into the lighting system, you have a readymade, distributed grid—no need for a separate physical infrastructure, separate power runs, or separate data cabling.
Important considerations for sensor networks include the density of the grid (number of sensor nodes per area), the type of sensors deployed, and the ability to extract meaningful data from the overall data stream. Sensors have become small and cheap enough to embed directly in the luminaire housing for very little incremental cost. The density of luminaires may exceed the required density of sensors, so flexibility in commissioning is also an important consideration.
Embedded light metering might be the key to solving the challenge of how to identify and respond to end-of-life events for LED lighting systems. Since LED light sources fade over time but rarely fail, it can be problematic to determine when a lighting system has dropped below the minimum threshold defined for an application.
For office lighting systems, end of life is often defined as the moment when the initial light output of the luminaires has depreciated by 30%. With LED-based lighting systems, this moment may not occur until after the system has been in operation for 50,000 hours or more (12 years or longer if the lights are on twelve hours a day, every day). If the system can automatically detect this event and send an alert, facility management can know when relamping is required.
Read the 5 ways that connected lighting uses data to deliver value beyond illumination here