Can home energy management systems show an appealing return on investment (ROI) for consumers?
Sure, says Mark Komanecky, vice president of marketing for energy management software company Eragy. In a CEProLive! web event, Komanecky showed two case studies Eragy has recently done that show that with investments of $1,000 to $2,000, homeowners can see a return in a year to three years. Komanecky’s presentation, “Stay Ahead of the Curve—Learn to Design and Sell Home Energy Management,” can still be viewed on CEProLive!
The first home, a 4,000-square-foot residence in Massachusetts, used Eragy’s Energy Monitoring Plus software, with energy info viewed via an existing Control4 home control system, along with a multicircuit power sensor that works with the Eragy software. The installation of the power sensing system and Eragy software was under $1,000, and the annual savings is about $350, resulting in an ROI of less than three years.
The Eragy system was able to monitor two central air conditioning units, an electric clothes dryer and two refrigerators, and two wireless Control4 thermostats were used to control the AC.
The key savings was achieved by the energy monitoring system being able to identify a rogue appliance—in this case a refrigerator using too much electricity. It was replaced with an Energy Star model. It was a simple solution to a common problem, though the amount of energy wasted may not have been apparent without the use of energy monitoring.
Intelligent Load Shedding
Eragy’s second case study took place in a 10,000-square-foot North Carolina home, also with an existing Control4 home control system using 13 wireless thermostats with some zone control, seven electric AC/heat pumps with gas backup, an electric clothes dryer and electric floor heat.
The initial investment was under $2,000 and required Eragy’s Intelligent Demand Side Management plus a TED (The Energy Detective) 5000 series power sensor with four MTUs (measuring transmission units). An annual cost savings of over $2,500, or about 28 percent, was achieved by limiting peak demand and thereby reducing steeper Time of Use and demand rate charges of utility Progress Energy (Time of Use rates can vary throughout the day, depending on demand, and Demand Rates are charged on prolonged peak usage periods, in this case an average peak of more than 15 minutes.)
Through the Eragy software, which features a utility rate engine, and integration with the Control4 system, savings were achieved by limiting peak demand and reducing energy spikes of 65 to 70 kw to about 20 kw.
“When the peak demand of the home exceeds a preset limit, the Eragy software starts to shed loads one at a time—this case, mostly heating/cooling via the 13 Control4 thermostats,” says Komanecky. “This home also has electric floor heat and a dryer that are part of the demand management system. These areas are shed via ZigBee high-current relays.”
“[Energy management] can actually be an ROI-driven sale,” says Komanecky. But don’t rule out energy monitoring, he advises. “Energy monitoring is the base application you need to work in the home energy management space. You need to monitor the energy before you can manage it.”