by Pekka Hakkarainen, Harold Jepsen, and Andrew Kriegman

Pekka Hakkarainen is Vice President at Lutron Electronics; Harold Jepsen is Vice President of Standards & Industry Relations for Legrand’s Lighting and Building Control Systems divisions; Andrew Kriegman is Executive Vice President of Leviton Manufacturing

Today’s energy-efficient buildings rely on well-planned mechanical heating, cooling, and ventilation systems, tight and well-insulated building envelopes, and lighting with carefully controlled solid-state illumination technology. Each building system works to reduce energy loss and judiciously manage energy consuming loads that support building operation and occupant comfort.

Yet, buildings also come thoughtfully constructed with hundreds of energy spigots, ready to serve up energy at the whim and want of thirsty electrical devices and equipment. It’s as if all work to carefully manage energy can be circumvented, with ready connections to a myriad of leaky energy faucets.

Each time a fumble in the dark, or uncomfortable bend under a desk finds an electrical receptacle to “plug in,” a potential leaky energy faucet is connected to a building’s self-service fountain. How can buildings aim for efficiency or keep energy use targets while electrical energy siphons abound? One answer is the managed control of electrical receptacles or outlets. Known as “automatic receptacle control” in the energy efficiency codes or commonly “plug load control” in the trade, it is the simple ability to shut off power to electrical receptacles, when plug in devices are not needed.

Automatic control of electrical receptacles is not a new concept, as controllable advanced power strips have been used for many years to manage plug in device energy waste. Only within the past 10 years have automatic receptacle controls come mainstream to commercial buildings infrastructure, with the 2010 version of the ANSI/ASHRAE/IES 90.1 energy efficiency Standard. The 90.1 Standard was soon followed by the adoption in California’s 2013 Title 24 Part 6 energy code. Since the codes do not permit plug-in controllable power strips, the electrical industry has an array of controlled receptacle products to match what the codes require. Some products control receptacles from the origination of the circuit feed in or close by the panel board. Some control receptacles at the branch circuit level and are distributed out in the rooms and spaces they serve. Others are self-contained receptacles that can easily replace an existing noncontrolled receptacle and receives its control signal to shut off wirelessly, so no added wiring is necessary.

Yet, in some building design and construction circles, automatic receptacle control is not well understood and there is skepticism regarding its benefits and effectiveness. Indeed, the skepticism has turned into objections to overreaching code mandates without benefits, and claims they result in safety hazards when people plug in extension cords to keep their devices or appliances powered. A recent informal survey of electrical building actors was conducted by an energy research group, to seek greater understanding of automatic receptacle control perception. It confirmed the skepticism and misunderstanding in the industry of automatic receptacle control use in buildings.

New and existing commercial buildings continue a downward energy use trend with fewer heating and cooling losses, more efficient lighting systems, and improved operating efficiencies for heating and air-conditioning systems. However, according to the U.S. Energy Information Administration, energy use by plug and process loads is expected to grow for the foreseeable future. This has prompted the Department of Energy’s Better Building’s Program, to create a Plug and Process Load Technology Research team, which works to create plug and process load energy reduction strategies.

 Automatically controlled receptacles are identified by clear markings on the electrical outlets as required by the National Electrical Code® section 406.3(E). Controlled plug-in receptacles will have the words “controlled” along with the universally recognized on/off power symbol. Outlets with these markings automatically turn off, or remove power to them when either no one is detected in the room, or as scheduled off by an automatic time switch or similar controlling system. Often, room occupancy detection cost-effectively piggybacks on controls already installed for the lighting controls. This automatic shut-off of power, stops power to electrical devices not needed when occupants are not in the room. These unneeded loads could be display monitors, printers, task lighting, space heaters, fans, audio/video equipment, and a plethora of other devices we plug in at our desks. Automatically controlled receptacles are not the place to plug in computers, medical devices, refrigerators, shared network printers, or uninterruptable power systems. Such devices requiring constant power, must be plugged into uncontrolled receptacles.

Installation of automatic receptacle controls required by energy efficiency codes is limited to commercial building rooms such as private offices, classrooms, breakrooms, copy rooms, conference rooms, guestrooms (California only), and individual workstations (like in open office furniture). The energy code provision requires at least 50 percent of the receptacles in these rooms be automatically controlled, leaving the other 50 percent of the receptacles to remain under constant power. When commercial building projects do not show modular furniture on the construction plans, at least 25 percent of the branch circuit feeders installed to power future modular furniture must also be automatically controlled. This ensures the modular furniture power system will have access to a controlled circuit for receptacle control when the furniture is installed.

Most of the energy efficiency codes require that a controlled receptacle be next to or within a specific distance from an uncontrolled receptacle. This prevents a safety concern with the use of extension cords when either a controlled or uncontrolled receptacle is desired for use, as either receptacle would be within reach.

Researchers have conducted studies illustrating the energy savings achieved by automatic receptacle controls. A study conducted by the Minnesota Department of Commerce’s Division of Energy Resources in October 2016 found that using occupancy sensor-based control of receptacles yielded a 21.7 percent average energy savings. Another August 2016 report from San Diego Gas & Electric’s emerging technology program indicated average energy savings of 19.9 percent from plug load control technology in office buildings. Other studies and reports have shown similar findings on energy savings achieved by automatic receptacle control strategies over the past ten years.

Another factor in a successful automatic receptacle control program is end-user education. If a user is not familiar with the controlled receptacle markings, or doesn’t notice them on receptacles under the desk, they may not understand the energy saving function the controlled receptacles provide. This can cause occupants frustration when they plug in a device, like a computer, that is not intended to be controlled. However, if they understand the difference, the function, and the correct device to plug into the right receptacle, they will play a key part in automatic receptacle control success and in the energy efficient operation of the building. In a sense, they will participate in helping the building’s energy efficiency success.

More information is available from NEMA Members who manufacture automatic receptacle control products and by visiting the U.S. Department of Energy’s Better Buidings Initiative website. Additionally, good education materials for automatic receptacle controls (plug load controls) can be found through the Lighting Control Association website with online training offered by the association’s Education Express program at  www.lightingcontrolsassociation.org.

So, before an energy faucet is plugged into a receptacle, take a closer look for the automatic controlled receptacle markings. Help play a part in saving energy, even just a leaky drip.