CLTC research, demonstrations and case studies have shown adaptive corridor and stairwell lighting systems are a cost-effective strategy for achieving lighting energy savings of 40–50%. This is because many stairwells and corridors are illuminated continuously, despite low occupancy rates, and are usually equipped with standard, non-dimmable ballasts and operated with wall switches or from a panel box.
Core sunlighting systems deliver sunlight deep into multi-story building cores, where daylight is not available through skylights or windows. An effective core sunlighting system offers physiological and psychological benefits to occupants while dramatically improving the quality and color rendering of lighting, reducing lighting electricity use up to 75%, and reducing electricity loads during peak demand periods.
CLTC is evaluating dynamic skylight systems that automatically adjust light transmission to minimize glare and manage solar heat gain, significantly improving both lighting quality and energy savings. Engineers are using one of the Center's integrating spheres to measure the transmittance of different sample units.
Applications include residential and commercial spaces that receive sufficient sunlight to require some form of shading for occupant comfort or to prevent solar heat gain.
Wall packs offer an effective means of illuminating building perimeters, bolstering security and aiding wayfinding, but many are limited in terms of their efficiency, with minimal or nonexistent cutoff. Moreover, because wall packs typically operate in areas with low occupancy rates, they often waste energy fully illuminating vacant spaces for hours at a time every night.
Photosensor control systems have been available for more than two decades, but they have struggled to gain widespread use due to issues with reliability. To address these issues, CLTC partnered with WattStopper, Walmart, Sacramento Municipal Utility District, Southern California Edison, and San Diego Gas & Electric Company to develop a more reliable, more effective daylighting control system capable of sensing changes in daylight levels with increased accuracy and responding with more appropriate adjustments in electric light levels.
To address California’s critical need for targeted, practical technology improvements that reduce lighting energy use and advance building energy-efficiency, in 2009, the California Energy Commission initiated a comprehensive lighting research, development, demonstration and outreach program in partnership with the California Lighting Technology Center.