Involving Consumers in Home Energy Management

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Demonstration projects recently completed by the U.S. Department of Energy's Pacific Northwest National Laboratory suggest new approaches for achieving more efficient home energy consumption. The Olympic Peninsula Project tested outcomes in a virtual market, wherein homeowners received the information and technology necessary to fine-tune their control of energy consumption within the home. The Grid Friendly^™ Appliance Project tested the effect of placing appliance-load controllers on residential water heaters and clothes dryers.

Interactive Energy Management

The 112 residences participating in the Olympic Peninsula Project were from cooperating utility service areas in the state of Washington. The region’s rapidly growing population is demanding more from the power grid, which is especially vulnerable to failure in severe winter conditions.

Homeowners in the Olympic Peninsula Project reduced their energy costs by using electricity at off-peak times and adjusting their home energy system controls to reduce consumption.

Homeowners responded to a well-publicized recruitment campaign and were selected for the year-long study based on several criteria. Participating homes needed to be equipped with high-speed Internet service, an electric HVAC system with 1 or 2 thermostats, an electric water heater with a capacity of at least 30 gallons, and an electric clothes dryer. The homeowners agreed to live in their homes during the project, substitute their revenue meters with advanced versions developed for the research, modify their home's electrical setup, and attach control boxes to walls. In addition, they were required to take pre- and post-surveys, interact with project equipment to select desired levels of comfort and cost savings, and allow access to the equipment in their homes for installation, maintenance, and removal. Motives for participating in the project included use of the equipment, a small cash incentive, and taking part in research that could advance efficiency and cost savings for homeowners.

The selected homeowners were assigned to one of three subject groups or to a fourth control group. Those in the control group had the project equipment installed in their homes but had no further contact with the demonstration. The other three groups received information and the equipment needed to manage their home energy systems. They could go online at any time during the project to review their energy consumption histories, in aggregate or for any 15-minute interval.

Participants in the fixed-price group were told that they did not need to modify their usual patterns of energy use, but they could choose to use more or less electricity to control their utility bill. The price of electricity would remain constant at 8.1 cents per kilowatt-hour, whatever their decision.

Participants in the time-of-use/critical-peak group could choose to reduce their utility bills by changing the time period during which they used electricity. The price of electricity varied for this group according to off-peak, on-peak, and critical-peak times. The lowest cost rate (off peak) was applied to midday, night, and weekend hours, when demand tends to be lower. The price for weekday early morning and early evening hours (on peak), when demand is highest, was set higher than participants were currently paying. The critical-peak rate was applied at times of power shortages or electrical grid emergencies and was much more expensive than the on-peak rate. Critical-peak events were rare, lasted no more than four hours, and were preceded by advance notice. Participants were able to set their equipment for comfort levels and to respond automatically to price signals, but they could also override the settings at any time.

A real-time pricing group received actual price information that not only varied every five minutes, but also changed in unpredictable ways. This demanded the greatest degree of consumer involvement and modification of energy usage of any of the groups. Members of this group went online to set and adjust automatic responses to price information. When prices were high, they could choose to use less electricity and override their own programming.

Consumers participating in the research saved an average of 10 percent on their utility bills. The time-of-use households reduced their consumption significantly more than other groups and enjoyed off-peak savings as well. Both of the price-responsive contracts, time-of-use and real-time, appealed to the participants. Consumers tended to set controls according to preference and leave them to operate automatically, but the ability to override settings also seemed important to participants. Members of one family that reduced its consumption of electricity by 15 percent related how much they had learned about using and saving electricity while becoming more aware of their comfort and tolerance levels. They appreciated the ability to override their own settings: "It [was] great fun to sit at a picnic table in an RV park and jump online through a Wi-Fi connection to tell the water heater and heat pump in our house to wake up and get to work, we’re coming home early."¹

Managing the Grid

Appliance-load controllers on clothes dryers and water heaters shut off the appliances whenever the electric power grid's voltage drops below 59.95 Hertz.

In the Grid Friendly Appliance Project, controller devices were placed on 50 water heaters and 150 clothes dryers in homes in Oregon and Washington. Whenever the electric power grid's voltage fell below 59.95 Hertz, the monitor/controller signaled its appliance to shed its electrical load for as long as the underfrequency event lasted. These brief events, ranging from a few seconds to 10 minutes, largely went unnoticed by consumers. Nine out of 10 participants in this project agreed that it would be acceptable to have the Grid Friendly feature as a standard or added option on a new water heater or clothes dryer.

Research Conclusion

The complete reports of these demonstration projects (www.pnl.gov/news/release.asp?id=285) relay methods, outcomes, and perspectives of cooperating utility companies, consumers, the system integrator, and equipment manufacturers. Although these demonstration projects revealed a number of constraints and new questions, particularly from the perspective of utilities and appliance manufacturers, one important conclusion was that consumers equipped with enhanced information and adequate tools tend to make better-informed decisions about energy use.

1. Pacific Northwest National Laboratory, "Pacific Northwest GridWise™ Testbed Demonstration Projects. Part I. Olympic Peninsula Project," October 2007, p. 8.12.