Intelligent Outlets, Commercial
Outlet: Intelligent vs. Conventional
Modular outlets that plug into existing outlets and are programmable to minimize equipment operation and "vampire loads" when plug load is not in use, and reports energy use to a computer or smartphone.
Item ID: 468
Multiple Energy Systems--Energy Management
Technical Advisory Group: 2014 Commercial Building TAG (#9)
Average TAG Rating: 3.06 out of 5
TAG Ranking Date: 03/17/2014
Many manufacturers currently offer intelligent outlets. These devices offer a variety of programmable scheduling, measurement, automatic and/or remote device control, and wireless energy use reporting capabilities. These units plug into regular electrical outlets to prevent vampire energy use, reduce the costs to operate electronic equipment, and monitor energy usage. Smart outlets support energy management efforts by measuring energy usage of connected devices and systems in the home or distributed office. They help identify power savings potential based on actual energy demand, not just manufacturers’ nameplate information.
In office settings, plugs loads can account for as much as 20% of energy use with computers, monitors, and laser printers being the biggest energy users other than space heaters, which are generally discouraged but nonetheless ubiquitous in some offices and other commercial buildings.(Horsey, 2012) GSA reports that approximately 21% of the total electricity consumed in their standard office buildings is due to plug loads (excluding data center and telecom equipment). The range varies widely, with plug loads accounting for anywhere between 8% and 35% of total building energy consumption (Metzger, 2012).
Estimates of energy savings from using smart plugs or power strips vary depending upon the type of smart plug used, which devices are connected to the plug, how the user currently operates the devices, availability of sensors and logic that automatically power down equipment when not in use, and the degree that the users operates the remote access and control features built into the smart plug. Savings are also dependent upon the automatic controls built into devices that switch to lower power or sleep modes when not in actual use and even the contrast settings used on monitors. In addition to occupant behavior, savings are heavily dependent upon device procurement practices---they are reduced when efficient devices are purchased and when aggressive power management settings are deployed.
BC Hydro tested ThinkEco Modlet (Modern Outlet) smart plugs at a small cabinet shop and found that they resulted in a 44% annual energy use reduction (about 280 kWh/Modlet). The BC Hydro tests yielded particularly attractive energy savings as portable electric space heaters were plugged into the outlets and historically had been left on all night. Smart plugs are best used with outlets with high plug loads.(Wilcock, 2012)
Baseline Description: Standard plug with no appliance control
Baseline Energy Use: 363 kWh per year per unit
Smart outlets can be used in the commercial sector. NYSERDA conducted a demonstration project with small businesses that involved sending 25 ThinkEco Modlets to each of 10 offices to use with a representative sample of non-server plug loads. Monitoring occurred for a period of two months each to establish a baseline, and determine savings under a "set it and forget it" and an "active engagement" approach. The potential energy savings at the 10 offices ranged from 675 to about 5,670 kWh year with the average annual potential savings being 2,813 kWh per small business. Potential savings were determined through examination of logged power data for the connected devices and considering power draws during off, hibernate, sleep, idle, and active modes of operation. The potential energy savings amounted to about 31% of the baseline annual energy use for the devices connected to the smart outlets.
The baseline plug load was determined for the outlets equipped with Modlets. It amounted to about 9,091 kWh per year for each small business or 363 kWh per Modlet deployed. (Perry, 2013)
ThinkEco Modlet smart plugs were also tested by BC Hydro at a small cabinet shop resulted in a 44% plug load energy use reduction (about 280 kWh/year per Modlet). The BC Hydro tests yielded particularly attractive energy savings as portable space heaters were plugged into the outlets and historically had been left on at night. Smart outlets are best used with outlets with high sleep mode loads or loads during unoccupied periods. Savings when used on equipment with on/off switches (such as drill presses) was negligible as was savings on music systems where users were in the habit of turning the equipment off at night. The baseline energy use varies tremendously due to what is plugged in to a wall outlet and the reliance on users to turn equipment on and off. Back-calculating from the BC Hydro report, the typical baseline energy use in a light manufacturing outlet is about 600 kWh. If someone was assigned to turn off the space heaters at night, the baseline use would be much lower. (Wilcock, 2012)
Manufacturer's Energy Savings Claims:
"Typical" Savings: 20%
Savings Range: From 20% to 50%
Best Estimate of Energy Savings:
"Typical" Savings: 26%
Low and High Energy Savings: 9% to 44%
Energy Savings Reliability: 6 - Approved Measure
NYSERDA conducted a demonstration project with small businesses that involved sending 25 ThinkEco Modlets to each of 10 offices to use with a representative sample of non-server plug loads. Monitoring occurred for a period of two months each to establish a baseline, and determine savings under a "set it and forget it" and an "active engagement" approach. Potential energy savings at the 10 offices ranged from 675 to about 5,670 kWh year with the average annual savings potential being 2,813 kWh per small business (or 112 kWh/year per modlet) valued at about $253 per office given a Northwest electrical rate of about $0.09/kWh. (ThinkEco, 2014), (Perry, 2013) Potential savings were determined through examination of logged power data for the connected devices and considering power draws during off, hibernate, sleep, idle, and active modes of operation.
The actual or realized savings obtained through deploying and programming the Modlets amounted to an extrapolated value of 1,220 kWh/year per small business ranging from 19% to 68% of the plug load potential savings. The reduction in the baseline total plug load (considering both active and sleep modes) was found to be 13.4% (This is the measured energy savings realized compared to the baseline measurements for all plug loads connected to the Modlets. Note: not all plug loads were connected. Refrigerators, for instance, cannot be turned off during non business hours) (Perry, 2013) This equates to an achieved energy savings of about $109 per year per business (@$0.09/kWh) or about 50 kWh per year per Modlet deployed. Realized savings are about 43% of the potential identified energy savings. (ThinkEco, 2014), (Perry, 2013) The value of these savings is about $4.40 per year per Modlet (@0.09/kWh). Given a first cost of about $71 dollars, the simple payback is about 16.1 years when both Modlet installation costs and debugging time are neglected. Note, however, that many of the Modlets were assigned to devices that did not warrant smart control i.e. phantom or controllable loads were minimal.
Ecos installed upgrades to control 39 devices at a library and a small office. Affected plug load energy consumption was reduced by 17% at the library and 46% at the office (Mercier, 2011). The low and no-cost energy savings strategies could save about 12,270 kWh/year at the library and about 5,180 kWh/year at the small business. (447 kWh/year per controlled device. Note that the Ecos recommendations went beyond smart plug control and included the purchase of more efficient devices and dimming of monitor contrast). A total of 924 plug load devices were in the two buildings so the project manager "cherry picked" the loads to be controlled and extended power management and timer control only to those energy consuming devices (4.2% of the total) with the greatest energy savings potential.
BC Hydro conducted field tests of the ThinkEco Modlet and achieved annual plug load energy savings of 44% during the winter period---equivalent to 280 kWh per smart plug deployed. Savings dropped to 14% in the summer (Wilcock, 2012). These savings might not be typical as, in this cabinet shop environment, portable space heaters were plugged into many of the wall outlets. These units had been historically left on at night, so energy savings from space heater control were unusually high.
Note that the primary target for energy savings for smart outlets is plug loads that occur during night-time and weekend (or non-business) hours. No demand reduction savings or benefits should be attributed to this technology. The value of the energy savings will decrease for utility customers that are under time-of-day rate schedules.
Note: Use of intelligent power strips is a deemed measure under the October 1, 2014 BPA "Energy Efficiency Implementation Manual". The deemed amount is $15 per strip
Energy Use of Emerging Technology:
268.6 kWh per unit per year
Energy Use of an Emerging Technology is based upon the following algorithm.
Baseline Energy Use - (Baseline Energy Use * Best Estimate of Energy Savings (either Typical savings OR the high range of savings.))
The energy use with the emerging technology installed is equal to the baseline plug load of 363 kWh per year (per outlet with Modlet control) less an anticipated 100 kWh per year savings due to use of smart outlets. Note that each Modlet has two sockets and each can be programmed separately. A conventional power strip can be plugged into a Modlet socket and used to control multiple devices with similar schedules. The 100 kWh annual savings assumes that smart plugs are only used with devices with enough potential savings to justify the purchase and installation of the smart plug.
Potential number of units replaced by this technology:
These outlets can control a number of loads, so it difficult to predict exactly where they will be used in the commercial sector. We use as a proxy for the number of loads that may be controlled in this way the number of desktop computers installed in the commercial sector. According to a Navigant report, in 2011, there were 74,000,000 desktops installed in the commercial sector in the US (Navigant, 2013 Pg 41). Take 4% of that, since the Northwest has a population of 4% of the US, to get 3,000,000 desktops in the region.
Regional Technical Potential:
0.28 TWh per year
Regional Technical Potential of an Emerging Technology is calculated as follows:
Baseline Energy Use * Estimate of Energy Savings (either Typical savings OR the high range of savings) * Technical Potential (potential number of units replaced by the Emerging Technology)
Installed first cost per: unit
Emerging Technology Unit Cost (Equipment Only): $71.00
Emerging Technology Installation Cost (Labor, Disposal, Etc.): $0.00
Baseline Technology Unit Cost (Equipment Only): $0.00
BC Hydro conducted a study under which 10 ThinkEco Modlets were installed for plug load management. Purchase and shipping costs were $709.99 for the ten units. Actual installation was easy (taking one hour for the ten Modlets) as the devices plug into standard wall outlets but have circuitry that monitors power consumption as well as executes schedules for turning each socket on and off. The Modlets connected with a local computer via a USB Key and a Zigbee mesh-network. For each Modlet, the user must enter the name of the connected appliances with the type of appliance selected from a drop down list. Modlets had to be activated one by one and connection via the Zigbee network became more problematic as the number of Modlets increased. After initiation, the Modlets didn't "stay connected" all of the time. Modlets were "lost" on the web-interface when they were moved to new locations in the building. About 14 hours of time was required to debug and connect the ten Modlets (Wilcock, 2012). BC Hydro concluded that opportunities for Modlet use are not prevalent (and they spent some time looking for opportunities) and the savings are small for the trouble involved.Once the system was up and running, the Modlet scheduling worked as advertised. BC Hydro concluded that it takes a devoted energy-saver to persever with this product.
Note: No installation costs are incurred as it is expected that the building operator would install the units thermselves.
Simple payback, new construction (years): 8.4
Simple payback, retrofit (years): 8.4
Cost Effectiveness is calculated using baseline energy use, best estimate of typical energy savings, and first cost. It does not account for factors such as impacts on O&M costs (which could be significant if product life is greatly extended) or savings of non-electric fuels such as natural gas. Actual overall cost effectiveness could be significantly different based on these other factors.
Reference and Citations:
Technical Trials of Ecobee and Modlet at Gillingham Cabinets
Energy Savings Opportunities with Home Electronics and Other Plug-Load Devices: Results from a Minnesota Field Study
Energy Center of Wisconsin
Analysis and Representation of Miscellaneous Electric Loads in NEMS
U.S. Energy Information Administration
Managing Plug Load is the Next Challenge for Energy Efficient Buildings
New Buildings Institute,
Managing your Office Equipment Plug Load
New Buildings Institute
Pilot Study: Plug Load Energy Management in Commercial Offices
Commercial Plug Loads
Managing Office Plug Loads
E-Source Customer Direct
Plug Load Energy Management for Smaller Businesses
Funded by NYSERDA
Commercial Office Plug Load Savings Assessment
Public Interest Energy Research Program (PIER)
Plug-Load Control and Behavioral Change Research in GAO Office Buildings
National Renewable Energy Laboratory