When a “bomb cyclone” blasted much of New England and caused widespread power outages, Eric and Alison Rector knew that their home was safe from the risk of freezing pipes. While neighboring farmhouses were without power for six days, the Rectors enjoyed most of their modern luxuries. Their 1,100 square foot high-performance home uses a dynamic combination of energy efficiency and solar energy with battery backup.
Solar System with Battery Backup Provides Emergency Power
The Rector’s 6-kilowatt solar system provided backup electricity during this record-breaking outage, giving the couple greater resiliency with extreme weather events. “One 48-volt battery bank gives us running hot and cold water, heat, ventilation, lights, and power for some appliances,” says Eric. “If our solar system didn’t have batteries, we would be stuck with no power during grid outages despite all our solar panels.”
The solar system was designed and installed by Sundog Solar and originally contained 3-kilowatts of solar panels and a battery bank. The couple later upgraded the system and added 3 more kilowatts of capacity. Because their home was built to the Passive House Standard, a stringent German certification for energy efficiency, the solar was producing more electricity than they were consuming, and Eric and Alison purchased a 2017 Chevy Volt to put the surplus to good use. They can now drive to and from town, powered by solar electricity.
The solar system inverter/charger give the Rectors peace of mind. “I call the Conext XW 4548 ‘the magic box’ because it seamlessly transitions between being on grid and off grid,” says Eric. “The way Sundog Solar designed the system, the ‘magic box’ keeps the battery bank full at all times when there is grid power. During outages, there is no need to switch anything manually. All our critical systems stay powered, and the solar system charges the batteries until the grid power returns.”
High-performance Home Saves Energy
The Rector home is located in Monroe, Maine and features a southern orientation, allowing for greater passive solar gains in the heating season. The house contains LED lights, an induction stove, lots of windows for natural daylighting, and triple-pane windows and doors. Structural insulated panels (SIPs), blown-in cellulose insulation, meticulous air sealing, and the Zehnder heat recovery ventilation system help the home retain heat during long Maine winters. Despite living in a cold climate, the couple used less than 1,000 kWh of energy to heat their home last winter.
Virtually Airtight Homes Require Ventilation
To prevent drafts, boost comfort, and save energy, the Rector home was air sealed. Although this is great for energy efficiency, an effective ventilation solution is crucial for ensuring healthy home air and exhausting excess humidity. Otherwise, contaminants would get stuck in the home, degrading indoor air quality.
Their Zehnder heat recovery ventilator (HRV) continuously provides a stream of fresh, filtered air to the living room, office, and bedroom. Stale or contaminated air is exhausted from the kitchen and bathroom.
Heat from the exhaust air is transferred to the intake air, saving energy. Zehnder HRVs are the most efficient on the market, and the Passive House Institute has certified some models.
The ventilation system keeps the home air fresh throughout the year. As cooking enthusiasts, Eric also appreciates how effectively the Zehnder ventilator removes cooking odors from the home while conserving energy.
Meticulous planning has paid off for the Rectors. Their carbon footprint is very minimal and they can power their car with solar electricity. An ultra energy efficient home and just one battery bank gives them relief from the challenges of an unstable electric grid.
“We know that on this road, the power goes off monthly, perhaps for just an hour or so,” explains Eric. “It used to be that if we had any high winds or storms, the electricity would go out. In the 1998 ice storm [when the Rectors lived in a neighboring house], the power went out for 11 days!”