Recent science tells us that we need to limit global warming to 1.5 degrees to avoid catastrophic climate change, and at COP26 (the 26th UN Climate Change Conference) in Glasgow this past two weeks many countries made commitments to reach net-zero by mid-century. But most have plans that are either non-existent or too weak to meet the target. Streetlights consume around 40% of a city’s energy, and one sure-fire way to reduce energy usage is by replacing old-style HPS and HID streetlights with modern LED lamps. But is that enough? LED lights can reduce energy usage by 50-60%, and the bulbs certainly last longer. But why stop there? If there was a way to save an additional 15% in energy use, shouldn’t a city do it?

I’m talking about smart lighting. Photocells are dumb. They go on when the ambient light goes down to a certain level (at night) and go off when the light is strong enough (in the morning). But because they are dumb, there is no way to either control them centrally or, more importantly, gather their status without going out and looking at them. How do you know when the photocell has failed and the light is permanently on? Do you need to have all the lights blasting at full power at 3am? This is where a smart lighting control system comes in. By implementing a lighting network using smart controllers instead of photocells, the whole streetlight network can be monitored and managed by a central management system or CMS. The additional cost is fairly small and easily recouped over a few years.

But a smart lighting network will improve your city streetlights’ efficiency and save as much as 15% more in energy use. Consider these advantages:

• No more day burners. When a controller fails and the light is on permanently the system will show you the exact location on a street view. No need to wait for someone to report it.
• Dimming control. A 25% reduction in power to some LEDs can result in a reduction of lumen intensity of only 5% – barely perceptible. Parking lots and highways can be dimmed in the early hours, with large energy savings.
• Lifetime prediction. LEDs tend to take more power as they reach the end of their life. Monitor the power usage of every light and replace it when its power usage becomes abnormal.

COP26, and COP1-COP25, have laid down the gauntlet to all of us – both the state and individuals – to do as much as we can to reduce our energy usage. When it comes to streetlight upgrades, skip the photocells and implement a smart lighting network. When your grandchildren ask you what you did to reduce global warming, you’ll have a good answer.