To reduce energy in a commercial building, business managers typically focus on efficient lighting, heating and cooling, and building controls. These practices are often costly and overlook the opportunity to trim plug-load energy waste with low-cost efficiency measures.
Plug load energy waste comes in many forms. The most common plug loads in offices include computers, monitors, printers, copiers, telephones and task lighting. Coffeemakers, water coolers, and kitchen equipment are also culprits.
Surprisingly, plug loads account for 33 percent of all U.S. commercial building electricity consumption, according to data from the National Renewable Energy Laboratory (NREL). In comparison, lighting uses only 20 percent, while heating, cooling, and ventilation use a total of 40 percent.
With a few low-cost modifications, office plug loads can be substantially reduced, resulting in operational efficiency and cost savings. Follow these best practices and you’ll be on your way to reducing plug-load energy waste and saving money.
- Evaluate existing plug loads. NREL suggests using a meter that logs plug load wattage weekly, has a sampling interval of 30 seconds, can measure loads up to 1,800 watts, can timestamp each data point, and can download stored data. This will help you evaluate each employee’s plug load usage and true electricity needs.
- Invest in motion-sensing or load-sensing advanced power strips. Advanced power strips are a low-cost measure that can be easily deployed in workstation and throughout the office to reduce wasted energy. A study The Minnesota Department of Commerce Division of Energy Resources found that advanced power strips with occupancy sensors saved 67 kWh per year per workstation. Furthermore, the EPA recommends plugging office electronics into a load-sensing advanced power strip, as they allow you to designate which electronics should always be on, and which ones do not need power when they’re not in use.
- Replace or remove old appliances in the break room or kitchen. Consider replacing aging refrigerators with ENERGY STAR models. If there are several small refrigerators throughout the office, replace them with one large refrigerator and you’ll save up to $35 a year in costs per mini-fridge, according to NREL. Removing underused vending machines will save $350 in energy costs per machine per year. If that’s not an option, ask your vendor for the newest machines without display lighting and with an electricity load–managing device. That simple step can net $310 a year per machine in energy costs. Consider other low-cost, energy-efficiency measures such as light-level or timer-controlled advanced power strips for small appliances like microwaves, water coolers, coffeemakers.
- Put computers to sleep. According to a report prepared by Ecos for the California Energy Commission, computers and monitors accounted for the largest share of energy among the office plug loads included in the study at 66 percent. To combat computer power waste, consider deploying a cost-effective solution such as the TrickleStar USB Motion Sensor, which automatically places the computer and monitor into sleep mode if no motion is detected in the workspace area. Alternatively, the PC Advanced PowerStrip+ is a more robust solution that, in addition to offering surge protection, reduces both active and standby power waste by the computer and peripheral electronics.
- Don’t forget about server rooms. NREL suggests installing an uninterruptible power supply that has at least 95 percent energy efficiency and meets the efficiency guidelines of the Server System Infrastructure initiative. NREL also offers a case study on how it improved energy efficiency in the data room at its headquarters.
- Educate your employees! Employee education is also key for addressing plug loads. This can include stickers or notes placed on office equipment reminding employees to turn off their equipment when it’s not in use. Take it a step further and create a friendly competition to motivate employees to improve facilities’ energy efficiency.