CLTC collaborated with the California Energy Commission and the California Institute for Energy and Environment (CIEE) to develop adaptive envelope technologies for retail and agricultural buildings. The objective was to develop systems that optimize both lighting and thermal efficiency in these facilities, using advanced fenestration materials, daylighting technologies and lighting controls.
CLTC partnered with Bonneville Power Administration, Pacific Gas and Electric Company and Southern California Edison to survey occupancy at four test sites in California and four test sites in Washington State. The sites selected for the research study represent market sectors identified as having the greatest potential to achieve energy savings with exterior adaptive lighting solutions.
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.
Last June UC Davis replaced 101 static HPS and MH wall packs with adaptive LED wall packs by Philips, equipping them with outdoor motion sensors by WattStopper and networked controls from Lumewave. Along with streetlights and post-top luminaires, the wall packs were incorporated into the Adaptive Campus Control System at UC Davis, via an RF network that provides campus-wide lighting control.
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.
In 2012, UC Davis upgraded its exterior lighting as part of the university’s Smart Lighting Initiative. Wall packs on campus, like other exterior lighting fixtures, were retrofitted with dimmable LED sources, motion sensors, and wireless controls. This allowed the units to be incorporated into an adaptive campuswide lighting control system. The system offers an intelligent, networked approach to lighting and energy management, with improved lighting quality and optimal energy efficiency.
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.
This document provides overviews of state-of-the-art commercial, residential, and exterior lighting strategies and technologies followed by detailed analysis that demonstrates the significant energy or electricity savings potential of several of these best-practice alternatives.