Lighting the way
Kevin Markell took an existing technology and put it to use in a new way. His LED parking lot light design is an improvement on traditional parking lot lights - delivering energy efficiency, better lighting quality and reduced total cost of ownership due to the long life and low maintenance of LED light sources..
In an example of coming full circle - Kettering University senior Kevin Markell brought the prototype of his LED parking lot light design back to campus from his co-op employer, to field test it and wrap up his thesis project.
Markell, of Davison, Mich., developed a parking lot light that uses LED light sources instead of a traditional bulb. “It is not a new technology, but my design does use a new LED product made by OSRAM Opto Semiconductors that is more energy efficient, smaller and the lifetime of the LED component is longer,” he said. OSRAM Opto Semiconductors, Inc. of Northville, Mich., is Markell’s co-op employer.
Utilizing the new LED product developed by OSRAM Opto Semiconductors, Markell built a reference design to show potential clients how to use the product for parking lot lights. He co-designed and worked with a team at OSRAM to build the prototype over a period of five months.
“It was very hectic,” he said. Essentially acting as project coordinator, Markell got first-hand experience coordinating efforts with suppliers and his OSRAM team. “I worked with actual manufacturers using their prototype products in the final design,” he said.
His design was a true collaboration of multiple suppliers and technologies, including: Power Vector for the power supply, Bergquist for the printed circuit board and thermal transfer materials, and Cooler Master for the heat sinks of the LEDs.
His motivation in developing an LED-based parking lot light was twofold – providing a good design for environmentally friendly, green lighting, and the market demand for more efficient parking lot lights.
“There is a big market for LED parking lot lights, and one of OSRAM’s goals is to help manufacturers of LED lights to make good parking lot lights – that’s my goal too,” Markell said. “With this project I was trying to promote our product and show end customers a good design.”
Interest in LED parking lot lights is primarily for reaping the benefits of reduced energy consumption and reduced maintenance intervals which means potentially reducing overall cost of ownership, he explained, “LEDs last longer and the improved quality of light can help to enhance security.”
The cost savings of LED lighting come from increased energy efficiency and their long life which means you don’t have to send someone out with a bucket truck to change out the light sources on regular intervals. “I think LEDs are the way to go for energy efficiency,” said Markell, estimating that a well-designed LED parking lot or street light will save around 55 to 65 percent of the energy used by an metal halide light or a high pressure sodium light which are currently the lights of choice for outdoor area lighting.
LEDs are ready for prime time and there are now LED retrofit lights available to replace some of the standard incandescent lamps you have in your home today. The benefits of LED lights are their long life, energy efficiency and their robust nature. LEDs are very robust and not so fragile as a filament based lamp when it comes to wear and tear if operated at low currents and at low temperatures. Many LEDs produced in the 1970s and 1980s are still in service today. Typical lifetimes quoted are 25,000 to 100,000 hours but heat and current settings can extend or shorten this time significantly, according to the U.S. Department of Energy.
The increased sense of security comes from how the light cast by LEDs and how it makes people feel. “LED lighting makes people feel more secure,” said Markell, “because it increases visibility and the ability to see color at night. LED light is more uniform, so there are less bright spots and shadows, and it reduces glare because there is less up-light,” he said.
His thesis adviser agrees. “This project is important from an environmental stand point in that the LED lights provide sufficient light needed for safety but use less power than the equivalent lights currently used,” said Dr. Laura M. Rust, associate professor of Electrical Engineering.
The LEDs Markell is field testing are at the blue end of the color space for LED white light. “LED lighting for outdoor night illumination is most effective in this range or color temperature,” he said, “it is easier for people to see at night with a bluish white light.”
To create his prototype, Markell hand built and milled the prototype with his OSRAM team. The process represented “lots of learning,” he said. “I had fun turning it on when I was done and it worked!” One of his challenges was to build control modules for the fixture to control the brightness of the LEDs.
Initially, Markell put his prototype on a light on a pole on campus along a driveway into the parking lot behind the residence hall and recreation center. Campus was the perfect place to go to test a prototype related to my thesis,” said Markell. “I wanted an installation to see if it worked, if peopled liked it, and if we were on the right track with our design.” To determine public opinion of the prototype, Markell developed a survey and asked the campus community to rate the prototype based on color and light coverage.
Patricia Engle, director of Physical Plant at Kettering, was excited by the idea of testing a co-op thesis project on campus and got on board, according to Markell. “Anywhere else would have viewed testing a prototype parking lot light as a liability,” he said, “here at Kettering it was seen as a learning opportunity.”
To round out his learning curve on designing and testing a prototype, Markell also trained in the use of a “cherry picker” and was able to go up on the lift and install the prototype himself – with a lot of help from Al Melwing, senior Maintenance electrician at Kettering. “Al trained me on the lift and now I’m an apprentice lift operator,” said Markell, “that was fun.”
As in many field tests, the prototype reacted differently in a real world setting than during the lab testing. “We experienced a few problems,” he said, “including higher voltage than in the lab tests and an arc short circuit in the LED modules. Apparently when the prototype was soldered, a little resin was left next to solder joint and it shorted across to the heat sink. This blew a fuse in the power supply and shut it down,” he explained.
Now fixed, the solder problem in the prototype showed Markell there need to be some recommendations for changes in the prototype before it is ready for commercial use.
On the second phase of the field test, Markell is going to use a lower voltage just to be sure the prototype has a better chance of surviving, and put it in an area with more foot traffic.
“The idea was to put up his prototype for the purpose of taking measurements,” said Kim Peiler ’02, the supervisor responsible for Kettering co-op employees at OSRAM. “His design is not yet sealed for the environment,” she added, explaining that once tested, other prototypes will be weather sealed and shipped around the globe for testing in different climates and for public reaction.
As long as the weather holds out, Markell will be able to finish field testing and make the necessary modifications to his design prior to sealing future prototypes, putting him one step closer to his goal of creating “greener” parking lot lights.
Written by Dawn Hibbard