Commercial Building Plug Load Energy Reduction Strategies
Scott Hackel (seventhwave), Lester Shen, Tim Ellingson, P.E., Rick Carter, Maureen Colburn — Jan 2015
The field team completed monitoring at all eight sites, and project lead Seventhwave has completed the data analysis and submitted a draft final report (link below). At all sites computer power management achieved the highest level of savings, and it was clear that a behavior campaign was crucial to driving savings. Full project update
Why this research is needed
Plug load energy use in commercial buildings is the fastest growing end use in US commercial buildings, projected to grow by 40 percent from 2006 to 2020. This stands in contrast to the decrease in other end uses such as cooling and lighting. There is a significant need to characterize the plug loads in office buildings, identify specific strategies for reducing these loads, and prioritize the strategies based on Minnesota’s energy savings goals.
We will conduct a broad, multi-level field study that measures the magnitude of these loads in typical commercial buildings and measures the potential for strategies to reduce this load. We will use 3 methods: (1) measure device-by-device where needed for accurate measurement, (2) measure entire circuits of plug loads where it is appropriate, and (3) characterize additional offices using a combination of site visits and online surveys.
Project process and expected outcomes
This study will examine a broad set of issues and strategies, and include loads such as PCs, monitors, kitchenette equipment, and copiers. We will perform detailed monitoring in representative office areas over the course of a year to observe enough variation in schedule, occupancy, and workplace activities. The statistically valid results will measure variations by workplace as well as season and business type.
Thirty to fifty buildings will be surveyed to characterize site and plug-load device information. From this initial work, eight to twelve buildings will be recruited to participate in a year-long study involving energy use measurement and plug load reduction strategies. Field measurements will be used to collect baseline data after which plug load control strategies will be implemented and the energy savings will be measured. Key considerations will be cost-effectiveness and accuracy. User satisfaction interviews will also be conducted to help identify the likelihood of adoption (based on satisfaction).
The study will use measured results combined with whole building energy use to assess the impact of reducing plug load energy on building energy use. This holistic analysis will allow the results of this study to be useful for more comprehensive programs such as new construction, custom, and retro commissioning, in addition to creating more prescriptive opportunities for Conservation Improvement Program (CIP) programs.
*This project is supported by a grant from the Minnesota Department of Commerce, Division of Energy Resources through the Conservation Applied Research and Development (CARD) program, which is funded by Minnesota ratepayers.
1Plug and Process Loads, Better Buildings Alliance
Image Credit: Robert S. Donovan, E Source