California Exterior Lighting Occupancy Survey

Occupancy-controlled luminaires have proven to have significant energy-saving potential in exterior applications such as residences, parking garages, parking lots, and pedestrian walkways. As a result, California utilities are deploying this approach throughout their service territories. To be able to predict with adequate levels of accuracy and precision and the level of savings to be expected from this approach, it is fundamental to determine typical occupancy patterns for a variety of exterior space types, since savings are highly dependent on occupancy rates, i.e. the percentage of time that a space is occupied. This project outlines a study for estimating the typical occupancy patterns of exterior spaces for occupancy-controlled luminaires throughout California. Because the effort and funding required are highly dependent on the number of sites, types of spaces studied, requirements for statistical accuracy and precision of results and technical solutions for site monitoring, this study is divided into two phases. In this project, Phase 1 will define the scope of the study, including key applications, as well as development of study methodology, implementation, and analytical requirements.

This Emerging Technologies (ET) project focuses on a methodology, or plan, to survey occupancy patterns in exterior spaces. Adaptive exterior lighting is a relatively new concept recognized by the lighting community as a potential method to increase energy savings in outdoor applications. In response to the increase in use of adaptive, exterior lighting products, and their potential for substantial energy savings, utilities and similar stakeholders require a method to quantify the expected energy savings associated with this emerging technology. Energy savings can clearly be tied to occupancy patterns in exterior space. The goal of this phase of the project is to scope out a survey methodology to use to generate standard occupancy rates for a cross-section of non-residential, exterior spaces. These rates may be used to determine expected energy savings, environmental and economic impacts for adaptive, exterior lighting. The detailed methodology was developed to identify and quantify pedestrian and automobile occupancy rates for various, non-residential exterior spaces. The methodology allows stakeholders to collect occupancy data by surveying selected customer sites in their respective territories. After data is collected, it is analyzed to develop a set of standard occupancy rates that may be used to estimate expected energy savings from the use of adaptive lighting. This methodology includes recommended survey metrics, data collection and analysis procedures, primary exterior spaces and applications to be included in the site surveys, appropriate data collection equipment, equipment placement, and other necessary monitoring requirements. The data is expected to provide the investor-owned utilities (IOUs) a baseline of occupancy patterns of exterior spaces that are lighted. That, in turn, allows the IOUs to design programs and strategies to optimize lighting of exterior spaces leading to energy savings. Results of this study will be used on a field study to determine appropriate incentives for installation of adaptive exterior lighting in commercial and industrial spaces. Adaptive luminaires with integrated occupancy sensors, that provide high and low light levels controlled by the sensor, could deliver significant energy savings. Expected savings will be calculated using the standard occupancy rates developed through this study. As such, it may be advantageous to conduct some studies with sensors on each existing fixture, if possible. This would allow for a more accurate representation of the occupancy patterns that individual luminaires would “see”, and thus may better estimate the savings from using fixture-integrated sensors in an adaptive lighting project, as opposed to a zoned, control strategy. The methodology detailed in this document, may be used for such a granular approach.