This project is funded by the California Energy Commission and seeks to demonstrate the strategies and benefits of integrating plug load control (PLC) with a building energy management system (BEMS).
Plug loads comprise a significant percentage of commercial building energy consumption. Applying intelligent controls to turn off plug loads when unused can provide dynamic load reduction and flexibility, which are key traits of grid-interactive efficient buildings. This capability is important for equitable decarbonization as it can enable disadvantaged communities to electrify buildings without costly upgrades to electrical infrastructure.
In this project, we present the effectiveness of various control strategies along with the operational lessons that informed their design. During a three-year period, we operated over 600 smart outlets in 12 university office buildings. The attached plug loads consisted primarily of printers, TVs, water dispensers, and copiers. After recording baseline power measurements for one year, we designed PLC strategies for each plug load type, use, and for different risk tolerance levels because PLC can potentially be disruptive to daily work. We used the Brick Schema to facilitate the management of plug load locations and other metadata. For advanced controls, we integrated the smart plugs with heating, ventilation, and air conditioning (HVAC) systems through the campus BEMS. We found static schedules to be the least disruptive and most predictable for occupants, resulting in 38% and 66% energy savings in two studies. For printers, print server-triggered PLC produced 86% savings, the highest of all strategies with minimal occupant impact. PLC of digital signage TVs produced simulated savings of up to 70% and the use of occupancy data from thermostats to control a waster dispenser yielded 32% savings.
PROJECT DELIVERABLES
- Data Taxonomy Glossary
- Advanced Plug Load Operation Strategies in Building Energy Management Systems
- Best Practices for PLC Brief
PUBLICATIONS
- K. Chia, A. LeBar, V. Agarwal, M. Lee, J. Ikedo, J. Wolf, K. Trenbath, and J. Kleissl. 2023. “Integration of a smart outlet-based plug load management system with a building automation system.” 2023 IEEE PES Grid Edge Technologies Conference & Exposition (Grid Edge), pp. 1–5. www.ieeexplore.ieee.org/document/10102749
- K. Chia, M. Ben-Ayed, S. Hebbur Eshwar, C. Zhang, E. Chen, Y. Gu, J. Kleissl, A. Khurram, J. Wolf, A. Van Sant, K. Trenbath, “Brick Schema Standardized Plug Load Control: Strategies for Load Reduction”, American Council for an Energy Efficient Economy 2024 Summer Study.
- L. Botman, Lago J, Fu X, Chia K, Wolf J, Kleissl J, De Moor B. “Building plug load mode detection, forecasting and scheduling”. Applied Energy. 2024 Jun 15;364:123098.