Business & Real Estate

LEDs and other green tech brewing at UC Davis lighting research center

Konstantinos Papamichael, co-director of the California Lighting Technology Center at UC Davis, shows a light-measuring device called a spectral goniophotometer at the center in June.
Konstantinos Papamichael, co-director of the California Lighting Technology Center at UC Davis, shows a light-measuring device called a spectral goniophotometer at the center in June.

In 2004, Konstantinos Papamichael began commuting from his Berkeley home to UC Davis’ California Lighting Technology Center, where he’d started working as an associate director and professor. The drive took him along Interstate 80 past the newly built Mondavi Center for the Performing Arts, but while his college degree was in architecture, his attention wasn’t focused on the building’s glass paneling or sandstone facade.

Instead, Papamichael thought about the Mondavi Center’s parking lots. In the evenings, they were fully illuminated despite being largely vacant, wasting lots of energy. There had to be a better way to create a safe environment while conserving energy, he thought. He and his colleagues ended up targeting the parking lots in a campaign that has revolutionized lighting on the UC Davis campus and elsewhere in California.

Papamichael recalls sending out graduate students with cameras at all hours of the night to photograph the brightly illuminated lots. The photos sparked a dialogue with UC Davis administrators, who eventually agreed to retrofit one parking lot with smart lighting technology as part of a pilot study, he said.

The pilot was a success, and in 2009, smart lighting was unveiled at the South Entry Parking Structure serving the Mondavi Center. The technology used 115 watts of power at “high mode” and adjusted to 35 watts at “low mode” when no motion was detected. Compared with the previous lighting system, which had used 175 watts continuously, the new lights reduced energy consumption by more than 50 percent.

Today, Papamichael is the center’s co-director, along with Michael Siminovitch, on the south edge of campus. The center was established by UC Davis, in collaboration with the National Electrical Manufacturers Association, the California Energy Commission and the U.S. Department of Energy.

The center develops energy-efficient lighting with market-friendly design, said Papamichael, who studied window design and daylight harvesting after immigrating from Greece. Ongoing projects at the center involve a range of indoor and outdoor lighting that reduces energy costs, meets customer approval and promotes better health. The center’s state-of-the-art equipment helps with product testing and demonstrations, while providing unique training opportunities for students from UC Davis and international universities interested in working on lighting applications.

“We are like a greenhouse,” said Papamichael, smiling through his stubbly beard. “Growing and preparing scientists and industry workers of tomorrow is one of the main missions” at the center.

One of the center’s first students was Keith Graeber, who joined in 2004 as an intern. Nearly 12 years later, he now serves as the center’s engineering director managing personnel and resources. Graeber said he continues to be motivated by the impact of lighting technology and its real-world applications, especially as the world races to find clean energy alternatives that can reduce fossil fuel consumption and carbon emissions.

“There’s a lot of gratification when everything we do results in a tangible outcome that you can see in the world,” Graeber said.

The center not only works with the university and other government agencies but also has formed strategic partnerships with manufacturers, designers and other stakeholders in energy-efficient lighting applications. The center’s demonstration showrooms allow retailers to compare old and new lighting technologies side by side to evaluate product appearances before making a large investment.

Retailers know lighting plays a critical role in a product’s appearance in a store or showroom. Papamichael highlights that by asking students to look at posters of different colored squares hung from the walls of a classroom. Papamichael then turns knobs and dials, adjusting the indoor lighting to contain more red, green or blue light. The light reflects and transmits different colors within objects, at one point causing color squares that appeared red to look a more convincing blue.

“Colors don’t exist,” Papamichael said. “They are perceptions in the brain.”

In general, stores are illuminated using soft lighting, emphasizing the reddish end of the spectrum, to create a warm and inviting atmosphere. Dressing rooms and display cases often use cool lighting that contains more blue light to help bring out a product’s true colors.

Another hot area of research has been LEDs, or light-emitting diodes, which are energy-efficient, solid-state light sources that illuminate when electric current passes through semiconductors such as the materials used in computers.

Over just the past few years, LED technologies have advanced at an astounding pace. An LED bulb that sold for upwards of $25 in 2013 cost only $5 in 2015, factoring in utility rebates and manufacture incentives. The life expectancy of an LED bulb is many years longer than an incandescent bulb’s, with only a fraction of the energy use.

LEDs have seen widespread use in traffic lights, car headlamps and advertisement displays. But a few challenges must still be overcome before residential and commercial spaces transition to LED technologies.

One challenge for Papamichael and his team is overcoming the lingering stigma of compact fluorescent lights. In the 2000s, the lights were heavily marketed for their substantial savings in cost and energy. But customers didn’t like the buzzing, flickering and, most of all, what many said was the unnatural feel of the light.

“The human eye has evolved to sunlight. Everything else is a crude substitute,” said Gabriel Taylor, an engineer at the California Energy Commission.

Still, both Taylor and Papamichael said they were optimistic about LEDs. In 2011, the U.S. Department of Energy awarded the L Prize and its $10 million award to the Philips company for developing a high-quality, high-efficiency LED to replace the incandescent light bulb, which emits a softer, more flattering glow.

The winning bulb was lined with yellow sections along its top to convert light from red and blue LEDs into soft white light. The Philips LED had a reported color temperature of 2,727K, which approximates the 2,500K of incandescent lights.

Lighting may have major implications for human health. One growing concern is nighttime exposure to blue light and its suppression of melatonin, a hormone produced in the evening that provides sleep signals to the body. Perhaps just as important as regulating sleep, melatonin is also a potent antioxidant, scavenging free radicals that may otherwise damage DNA and result in cancer.

Scientists have reported links between all-day exposure to blue light and increased rates of cancer, diabetes, heart disease and obesity. During the day, blue light is beneficial for boosting mood and alertness, but in the evenings, it disrupts circadian rhythms and prevents our bodies from achieving rest.

Papamichael sees a government role in creating lighting quality standards that can protect consumers in much the same way that protections exist for air and water quality. Current lighting standards primarily focus on reducing energy use to lower costs and carbon footprint.

No doubt, lighting represents a tremendous source of potential savings in energy and greenhouse gas emissions. Of the electricity used by California households in 2009, about 44 percent was for lighting, electronics and appliances. Electricity production in California produces about 50 million metric tons of carbon dioxide each year, one of the state’s largest sources of carbon emissions.

In the years since the Mondavi project, the center has improved lighting in other UC Davis parking lots as well as in dormitories, building corridors and office spaces. In 2010, UC Davis launched its Smart Lighting Initiative, which has installed efficient lighting and advanced controls across 42 campus buildings. Energy savings are estimated at about 12.5 million kilowatt-hours per year.

Papamichael said the lighting revolution is catching on at college campuses throughout the state.

“Michael and I have been doing this for 35 years,” he said. “The most important thing is that we continue to effect change that affects energy efficiency.”