Smart Solutions for Pesky Plug Loads

Plug loads—the power drawn from devices that remain plugged into the wall—are a nonstop source of aggravation for facility teams trying to lower building energy use.

These devices include anything from printers and copiers to vending machines, coffee machines, and refrigeration units, and their plug loads can vary greatly based on the device’s age, manufacturer, and frequency of use. They may consume anywhere between 8 and 1,000 watts, according to Siddhartha Chatterjee, general manager for Breakthrough Initiatives at Honeywell Building Automation. Plug loads account for 25-50% of a commercial building’s total energy consumption depending on the facility type, occupancy, what the space is used for, and how many devices are used, according to the U.S. General Services Administration (GSA).

“Visibility and control over the plug loads are important to managing the energy use of a building,” Chatterjee explained.

Why Are Plug Loads So Hard to Combat?

“Most buildings rely on physically unplugging devices or manually disabling plugs to manage power loads, which begs the question: Who is ultimately responsible for doing that?” Chatterjee said. Building occupants frequently don’t unplug their devices, according to a recent Honeywell survey conducted by Wakefield Research. The survey, which spanned May 30 to June 5, 2024, gathered responses from 1,000 office professionals working in office buildings with at least 50 employees and discovered three key findings:

• 57% of respondents either never unplug their devices (26%) or only unplug them when there is a reason, like troubleshooting an issue or going on vacation (31%).
• Employees often can’t access the plugs to unplug devices or aren’t sure whether they are allowed to unplug them.
• It’s unclear who should be responsible for managing plug loads.

“Not only do employees not have a clear understanding of who is responsible, but there is a certain level of out-of-sight, out-of-mind,” Chatterjee said. “Plugs are often hidden behind devices, under desks, or in other difficult to access places, so employees are hesitant to go out of their way to unplug devices, particularly ones they are unsure if they should or not.”

4 Ways to Reduce Plug Loads

Traditional plug load strategies often revolve around employee advocacy—asking employees to either shut their devices off or unplug them when they’re not in use, Chatterjee said.

“This is especially true in organizations that have shifted to a hybrid working model—it’s important to ensure that devices are powered off or unplugged when an employee is not in the office,” Chatterjee said. “Work from home presents an opportunity for companies to save plug loads on the days when minimal employees are in the office.”

Some companies use breakers that turn off power to an entire area in the workspace, but this is dependent on the type of space—you wouldn’t use this solution for a breakroom where you’d cut off power to the refrigerator, for example. “Overall, because these are manual processes that rely on someone there to physically power down or unplug devices, results are inconsistent and unreliable,” Chatterjee added.

Eliminating the manual aspect and automating some part of the process can both deliver more consistent results and free facility teams from having to police plugged-in devices. There are several options available to more proactively address plug loads. They include:

1. Autonomously powering down unused outlets based on space usage schedules or occupancy data. Solutions like Honeywell’s Connected Power integrate into the existing building management system (BMS) with open standards and are able to monitor and manage power usage.
2. Smart power strips, which allow some receptacles to remain on while others are turned off.
3. Personal occupancy sensors on power strips that de-energize certain loads, such as computer monitors, printers, or task lighting, during periods when areas are unoccupied.
4. Vending machine controls for refrigerated or non-refrigerated machines that cycle refrigeration and lighting during long periods of non-use.

“It’s important for building owners and facility managers to know that the once seemingly impossible task of managing and reducing energy usage at the plug level is now possible,” Chatterjee said. “The level of energy use is only growing as the number of devices connected to a building’s infrastructure continues to grow. While companies continue to optimize their building efficiency in other areas, reducing plug load is another way to maximize energy efforts across a company’s portfolio.”