If you’ve ever driven a Toyota Prius hybrid, you know the car’s dashboard includes a monitor that displays which power source is operating and how many miles per gallon you’re getting. The functionality has spawned a practice called “hypermiling,” in which drivers squeeze every little bit of fuel efficiency out of their cars by making adjustments to the way they drive.
Now homeowners can do the same thing. An array of manufacturers offer residential energy monitoring and management systems that serve much the same purpose. These “dashboards” give feedback that homeowners can use to maximize a house’s energy and resource efficiency, and help your homes live up to their performance expectations. And some manufacturers are adding even more advanced features that will help them monitor and control the sources and use of resources.
At the most basic level, energy monitors provide a simple readout of the total amount of energy the home is using, often by attaching a sensor to the electric meter that sends a wireless signal to the in-home display. The monitors may show the dollar cost of the electricity based on electric rates that the user enters or may let users monitor energy usage by day or time.
Research has shown that even such basic feedback can lead to savings. In a 2006 paper “The Effectiveness of Feedback on Energy Consumption” for the University of Oxford, Sarah Darby says the literature demonstrates “that instantaneous, direct feedback in combination with frequent, accurate billing is needed as a basis for sustained demand reduction.” She adds that the norm for energy savings from direct feedback is 5% to 15%, and studies using a table-top interactive cost and power display unit have shown savings as high as 20%.
“If you can see it on a display, people then take a real interest in lowering [energy] demand,” says Keith Davis, president of Residential Technologies, a Charlotte, N.C.–based electrical and electronic systems contractor. “Having knowledge allows them to control energy use within their budget and financial means and within their lifestyle.”