Street lights keep people safe and comfortable. They show the way. They light evening walks and morning runs. They guide people home. The City of Edmonton maintains more than 110,000 streetlights in neighbourhoods and along roads so that lights can keep doing their vital work.
Old-style bulbs can be a perennial challenge, however.
“The failure rate with HPS bulbs is close to seven percent per year,” said Olga Messinis, Director, Traffic Operations with the City of Edmonton.
“The move to LED lights makes a big difference. LEDs are more reliable. They look better. And they save money.”
Here’s a look inside a high pressure sodium (HPS) streetlight bulb retired from inefficient duty on June 3, 2020, near St. Boniface Catholic Elementary School at 118 Street and 40 Ave.
In HPS lights, an electrical charge is passed through the chemical to create light. The technology wastes a significant amount of heat energy.
Here’s what’s taking its place:
LEDs (light-emitting diodes) are more environmentally friendly. An electric current is passed through a semiconductor to create light. LEDs emit the same amount of light, but are more efficient.
In the most recent City of Edmonton maintenance report, LED street lights were found to have an annual failure rate of 0.0035.
“That’s a really small number, but a really big deal for taxpayers,” said Messinis.
LEDs rarely fail before their manufactured end date. LED streetlights draw 35 percent less energy and last four times longer than HPS bulbs. Win. Win.
LEDs also emit less light pollution. They can be adjusted so light is focused where it needs to be, such as intersections to enhance safety instead of into private property where light may disrupt people’s privacy or sleeping habits.
By the numbers
From 2011 to 2019, the City upgraded 53,000 streetlights to LEDs. This year, the City starts a three-year program to convert another 46,000 to LED.
This program will save the City $1.2 million a year in power and maintenance costs, and cut greenhouse gas emissions by 5,500 tonnes.
For Can-Traffic, whose crews are experts in LED technology and installation, the new lights help show the way ahead.
“LEDs consume significantly less power than the older, energy-hungry HPSs, which reduces the strain on power plants and in turn reduces airborne pollutants,” said Colwyn Kelly, President of Can-Traffic Services Ltd.
“The future potential uses of LEDs combined with smart technology is very exciting, the potential to control the lighting remotely opens up a whole world of possibilities.”
Kelly said light is a force for safety.
“We strongly believe street lighting places a vital role in the safety of drivers, pedestrians, bicycle riders and all road users.”
Illumination of choice
LED lights are travelling at the speed of a good idea.
This year, the Terwillegar Community Recreation Centre converted 71 main lights to LED as part of its $1.4 million construction project. The switch out process will continue in other City recreation and leisure facilities.
“The LED program is one of the ways the City of Edmonton is meeting customer needs without costing taxpayer money or costing the environment as much,” said Messinis. “It contributes to making our city more sustainable and climate resilient.”
Editor’s note: May 31 to June 6, 2020, is Environment Week at the City of Edmonton and here on the Transforming Edmonton blog.