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When TriMet planned its Milwaukie Park & Ride facility, electrical engineers knew long-lasting and durable lighting fixtures would be needed to keep the area lit well.

For its other Park & Ride facilities, TriMet had used high-pressure sodium lamps. They were bright, but also highly inefficient and burned out after only about 16,000 hours.

So, electrical engineers Flaviano Reyes and Rick Harrison of Reyes Engineering asked the transit agency to consider employing old lighting technology that is seeing new performance improvements.

Light-emitting diodes, better known as LEDs, have been around since the 1960s. But their popularity has increased recently due to advances in the semiconductor industry.

A 120-watt LED, for example, performs 57.6 percent more efficiently than a 350-watt high-pressure sodium lamp.

“When you look at outdoor lighting, LEDs start to outperform conventional lighting in terms of efficiency,” Reyes said. “It’s the same amount of light as a high-pressure sodium lamp, but it’s distributed better. You get the light where you want it.”

Being able to choose exactly where the light fell was important for TriMet, spokeswoman Mary Fetsch said. Certain areas monitored by security cameras at the Park & Ride needed to be lit well.

“LED lights tend to be directional, which is a disadvantage for most general lighting applications,” Fetsch said. “But it’s used to our advantage for parking-lot floodlighting. They provide more control over what is illuminated, which reduces light pollution.”

Fetsch said TriMet will save money on energy use and maintenance by using LEDs, which last for about 50,000 hours. They are also more durable than high-pressure sodium lamps, which have glass tubes that can break more easily.

“Up front, LEDs cost more money than other lighting options,” Reyes said. “But from a maintenance standpoint, the costs over time would be less for TriMet.”

Multnomah County’s transportation department has been researching whether existing streetlights could be converted to LEDs. The county has eight LED streetlights set up on the east-side ramp for the Morrison Bridge.

“We’ve been interested in LEDs for a long time, but we felt that in the past they couldn’t adequately replace our current streetlights,” said Jon Henrichsen, lead engineer for Multnomah County’s bridge department. “But we heard they had used LED lights on the replacement bridge for the (I-35W Mississippi River Bridge) in Minnesota, so we decided to test them.”

The LED lights emitted a clean, white light, Henrichsen said, that allowed pedestrians to see colors better than in the yellowish light emitted by the high-pressure sodium streetlamps. The LED streetlamps also use just 90 watts; existing streetlamps use 250 watts.

But the high-pressure sodium lamps cost only $150 apiece, while the LED streetlamps each cost $1,000. Multnomah County applied for federal stimulus money to pay for projects to replace certain streetlamps with LEDs, but was denied. As a result, the county won’t be adding any LED streetlamps anytime soon.

“We can’t do it unless we’re given a grant of some sort,” Henrichsen said. “Even with how long they last, the payback was still six or seven years out. If cost gets closer to $500, the payback would be fairly quick. I expect the cost to come down in a few years. It always does.”

The Energy Trust of Oregon provides incentives to encourage use of LEDs, according to Susan Jowaiszas, business sector marketing manager for the nonprofit organization. TriMet plans to use LEDs for its new streetcar maintenance facility in Northwest Portland. Lighting for that project will cost $19,000, but TriMet will be able to recoup $10,000 by using Energy Trust’s custom incentive.

“LEDs are becoming more popular for these outdoor applications,” Jowaiszas said. “To be eligible for our incentives, (the LEDs) need to be Energy Star qualified, or meet those criteria, and they must meet cost effectiveness standards. LEDs work best in certain situations and we want to make sure they perform.”