Plug loads, according to a pilot study performed by New York-based green technology company ThinkEco Inc., make up the fastest growing end-use of electricity in the commercial sector. As the amount of electricity used by plug loads grows, it becomes increasingly important to manage it. Electrical contractors can help their customers, but this requires an understanding of how plug-level energy management works and what tools are available.


Plug-level energy management comes in various forms. According to Ryan Egly, application engineer with Schneider Electric’s Connected Home Group, the most basic form plugs into the socket and performs a timing function. The next level involves local control and can either plug into the socket or be the socket. The last level usually involves a type of wireless protocol that communicates through a Wi-Fi router or a smart-energy gateway.


“For these systems, the contractor can provide basic networking services in addition to installation [when controllable sockets are used],” Egly said.


Usually, the hardware could be either a surge-­protection device with energy management capabilities or a stand-alone module that monitors and controls the device plugged into it. The software interprets the information provided and produces reports that enable the user to make energy decisions. Regardless of what form the energy management platform takes, it allows devices and equipment to be managed at the plug level.


“Plug-level energy management platforms monitor usage by individual load, provide automation capabilities through a scheduler or other types of control mechanisms and intelligence, alert users to potential faults before they happen by monitoring real-time data per device and identifying patterns within it, and provide reports that enable building owners to understand how people, devices or groups are using power,” said Walter Shimoon, vice president of sales and marketing for Enmetric Systems Inc., Belmont, Calif.


What should happen and why?


When owners are engaged only in top-level, building-wide energy management initiatives, they are only controlling about half of the energy load, i.e., the larger electrical system loads, according to Dave Perrotta, vice president of operations and engineering for Electronic Systems Inc., Knightdale, N.C. 


“The remaining 40 percent of energy usage is at the plug level,” he said.


When a proper plug-load energy management platform is deployed, building owners gain a level of granular data that unlocks savings in many ways, including base-load reduction, peak-load avoidance, the use of demand-response triggers that turn off select plug loads as needed, improved preventative maintenance programs, a better understanding of building occupancy, and the ability to comply with the increasing number of building codes that are requiring plug-load management as part of all new construction and renovation projects, Shimoon said. 


“In addition, plug-level energy management enables companies to demonstrate they are accomplishing the conservation goals laid out by their sustainability plan,” he said.


Upfront investments for plug-level energy management are typically a fraction of those required for heating, ventilating and air-conditioning (HVAC) and complete lighting conversions, Shimoon said, and the return on investment over a 10-year period can be between 2 and 4.25 to 1.


According to Perrotta, even if the system only turns off devices during non-use hours, the return can be as fast as 12 to 18 months after implementation. 


“In addition, the system can help analyze energy usage, remotely monitor equipment to determine where energy drains or misuse is occurring, and help make equipment- and device- purchasing decisions,” he said.


The takeaway


“There is an increased demand for this type of energy monitoring and reporting, and contractors need to know that end-users are looking for specific data to better understand energy consumption down to the device level,” said Philip Santoro, electrical contractor segment manager for Schneider Electric.


Beyond taking the time to identify what devices the customers wants to monitor or control at the plug level, there aren’t many implementation challenges. Nonetheless, electrical contractors need to understand how the platform is connected to the customer’s environment. 


“It’s going to be a harder implementation if all the devices need to be connected to the building’s network infrastructure,” Santoro said. 


In those instances, the EC needs to consider recommending a platform that doesn’t require heavy information-technology-infrastructure integration.


Plug-load energy management is the most individualized component of an enterprise’s energy management program, according to Shimoon. 


“Each employee’s plug-load control profile might vary greatly, and more sophisticated customers are demanding very user-friendly tools that allow individuals to customize their own plug-load profiles,” he said.


In the future, smart mobile devices will be key, and ECs need to be prepared for tight integration between the building’s energy management system, mobile apps and microlocation services.