Smart Plug Load Controls Integrated with Building Energy Management Systems
Integrating smart plug load controls with building energy management systems
The Regents of the University of California, on behalf of the San Diego campus
Recipient
La Jolla, CA
Recipient Location
38th
Senate District
77th
Assembly District
$712,190
Amount Spent
Completed
Project Status
Project Result
The project has ended, and the project team has installed 1,572 plug load controllers in 26 buildings. Out of those, 808 plug load controllers were installed in the Glendale Unified School District, and 764 plug load controllers were installed at the University of California, San Diego (UCSD) campus. A BRICK server metadata and communications interface have been built to configure and manage the plug load controllers. A print server application was developed to integrate plug load controllers with the UCSD print server application. The UCSD controllers collected baseline energy use for 12 months. Multiple plug load control trials were executed to actuate printers, display screens, and water dispensers. Static schedules proved 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. Scheduling of water dispensers based on occupancy measurements produced 32% savings.
The project team has continued to build upon the lessons learned from this project by partnering with the UCSD Sustainability Office and their Green Office/Labs program. Several biology laboratories participated in studies to catalog equipment such as fume hoods, waterbaths, centrifuges, microscopes and other laboratory plug loads.
The principal source of knowledge transfer is the Plug Load Management Application software that was published open source on GitHub. The release is accompanied by a journal paper that describes the software and provides example applications.
Project information was further shared through a webinar with NREL and four publications including a best practice brief for plug load control, a peer reviewed journal paper, and two peer-reviewed conference papers including one for the 2024 American Council on an Energy Efficient Economy (ACEEE) Summer Study.
The Issue
Twenty seven percent (27%) of California commercial electricity consumption in 2018 was due to plug loads. Most plug loads have no power management capabilities and are left on 24/7. Even if plug loads have energy savings settings, those settings often have not been set up or have been disabled. Integrating plug load controls into building energy management platforms can yield many energy and non-energy benefits, including integrated control of multiple building systems (especially for plug loads and HVAC) and automated and dynamic load control such as during demand response events.
Project Innovation
This project will demonstrate cost-effective reduction of energy use in buildings by integrating smart Plug Load Controls (PLC) with existing Building Energy Management Systems (BEMS). Smart PLC will employ advanced machine learning techniques to monitor and control the plug loads (PL), leverage BEMS sensor data for PLC and vice versa, and detect and resolve faults. Integrating PLC with the BEMS allows utilizing occupancy and temperature readings for dynamic PLC scheduling. BEMS integration will also facilitate participating in CAISO demand response markets and utility demand response programs based on the predictability of the reduced load profile and granular and aggressive PLC. Minimizing PL energy usage will result in significant energy reduction of overall building energy use that goes beyond what would be achievable with PLC alone. Commercial partners with widely deployed state-of-the-art PLC and BEMS technology will ensure the success of the project and immediate technology transfer.
Project Goals
Project Benefits
Through field studies involving over 600 smart outlets, the team demonstrated energy savings between 38% and 66% using static schedules, which were found to be the most predictable and least disruptive for building occupants. A specialized print server-triggered strategy for printers achieved the highest efficiency, reducing energy consumption by 86% with minimal impact on users. Additionally, occupancy-based scheduling for water dispensers resulted in a 32% energy saving, providing a simple payback period of approximately three years. Beyond immediate energy reductions, the project yielded technical benefits through the creation of an open-source Plug Load Management Application and the use of the Brick Schema to improve system interoperability and scalability. Economically, the implementation of these controls in California office buildings is estimated to save between $20,000 and $24,000 annually per building, depending on the level of control complexity.
Affordability
Annual energy savings translate to lower energy cost to ratepayers. The ability to manage their PL energy usage, allows ratepayers to strategically adjust PL consumption given time of use (TOU) rates.
Reliability
Reducing peak energy usage by PLC can help ratepayers during demand response events and CAISO Flex Alerts. Aggressively turning off PL can prevent rolling blackouts during times of grid stress. Being able to shut off a large fraction of unused PL can significantly contribute to reducing peak energy usage.
Key Project Members
Jan Kleissl
Felix Villanueva
Subrecipients
Johnson Controls, Inc.
Best Energy Reduction Technologies
Match Partners
Johnson Controls, Inc.
Best Energy Reduction Technologies
