There is a market on the horizon expertly tailored for the electrical contractor. Welcome to the rebooted all-electric home, where “clean electricity” takes on a new meaning.
Today’s “all-electric” homes represent a preliminary effort, but one drawing attention in a world attuned to aggressive energy efficiency and calls for reductions of carbon emissions. With the help of clean, solar energy, an all-electric home—if sized right and built with a tight envelope—can achieve, or nearly achieve, zero emissions (net-zero). Already supporting this market are a handful of utilities, developers and manufacturers that are refining, developing and introducing technologies tailored for the seriously energy conscious.
Something old made new
All-electric homes are not new. In fact, nearly 25% of homes in the nation were identified as all-electric in 2015, according to the U.S. Energy Information Agency. Such homes were trendy during the 1950s-70s. By 1960, under the banner “Live Better Electrically,” more than 850,000 families lived in a “Gold Medallion” home, a program sponsored by the Edison Electric Institute and supported by General Electric Co. and Westinghouse Electric Corp. Such homes featured the latest technologies, including electric washers and dryers, waste disposal units, refrigerators and heating. These modern homes offered what was billed as “clean electricity.” Few looked askance at electricity fueled by coal and saw no contradiction. However, painful power rate hikes and natural gas’ popularity for home heating and appliances overturned the all-electric home market.
For proponents of all-electric homes, the timing seems ripe for a return. The term “clean electricity” is now a far more circular concept as power grids work to decarbonize.
“Electricity from the grid is getting cleaner and cleaner, so the environmental impact of electric end-uses installed today gets better and better over time,” said Justin Margolies, senior energy research analyst for Slipstream, Madison, Wis., which serves 21 states by partnering with utilities, local and state governments, regulatory agencies and other organizations to create new solutions to energy challenges.
“Also, a smart grid can support an electrified home by providing the right market signals for when electricity is cheap and clean versus when electricity is expensive and dirty,” Margolies said. “Flexible electric end-uses can respond to these signals.”
The Electric Power Research Institute, Palo Alto, Calif., defines electrification in part as “the adoption of electric end-use technologies that displace other commercial energy forms.”
All-electric homes would feature mechanics, appliances and LED lighting powered by emission-free electricity. All could be programmable to deliver an energy-efficient and emission-free home. While the gas line does not disappear, new homes could forgo one. Technologies include air-source heat pumps, geothermal heat pumps, heat pump water heaters and clothes dryers, and induction stovetops. Electric vehicles play a role, with homes being wired for charging stations.
“Electrification can be an all-in or incremental strategy,” Margolies said. “For new homes, going all-in on electrification makes sense since costs for a gas connection, piping and fixed monthly charges can be avoided altogether.”
Margolies explained mixed-fuel existing homes can be a workable compromise for single-family retrofits and possibly new multifamily projects tasked with meeting stringent energy codes.
The heat pump grabs center stage
The biggest difference between yesterday’s and today’s all-electric home is the heat pump, which may be a rather new technology for many builders and contractors. For space heating, there are two types of heat pumps: a ground-source heat pump draws renewable thermal energy (heat) from the ground, while an air-source heat pump draws heat from the air.
“Heat pump technology, which can be applied to space heating, water heating and even clothes drying, draws on renewable thermal energy and uses the power of electricity to reach ‘energy efficiencies’ substantially greater than 100%,” Margolies said. “Naturally occurring heat is the ‘fuel,’ while a compressor and fan are wired electrically.”
Margolies mentioned that homes have contained versions of heat pumps for years: “Your household refrigerator is a heat pump that moves heat from inside the fridge to the outside,” he said. “This is why if you put your hand on the back fan, you’ll feel warm air blowing out. A central air conditioner is also a heat pump. The main difference in what constitutes an ‘air-source heat pump’ is that there is a reversing valve that changes the direction of the refrigerant flow so that instead of absorbing heat from inside and expelling the heat outside, heat is absorbed from the outdoor air and moved inside.”
Early adopters from all corners
A handful of utilities have developed programs to support the emerging all-electric home market. The Sacramento (Calif.) Municipal Utility District, a community-owned, not-for-profit utility, has its All-Electric Smart Homes Program that incentivizes home builders to construct new, all-electric and all-electric-ready, single-family or multifamily homes. ComEd, serving Chicago and greater Chicagoland area, has the Electric Homes New Construction program, which Slipstream helped design.
“Many utilities are starting to introduce such programs, seeing the need for electrification and programs that influence movement in that direction” said Kellen McSweeney, Slipstream program manager. “This program [with ComEd] is currently in the second year of its pilot and will become a full program starting in 2022 due to its early success. One large goal is to encourage and educate home builders to go all-electric. This includes introducing potentially new technology to builders, debunking myths about heat pump technology in this region and supporting their efforts by making introductions to home energy raters and contractors who already are knowledgeable in this area.”
McSweeney said the program currently offers a $2,000 incentive per home for the builder and a $200 incentive per for the energy rater.
“The market is just beginning to shift from early adopters to more builders who are dipping their toes in all-electric homes for the first time,” she said.
One of those builders is Scott Sanders, president and CEO of BrightLeaf Homes LLC in Hinsdale, Ill. “[ComEd] found us. So, a happy coincidence to apply some incentive, but we already had this [all-electric home] in development,” he said.
Three demo all-electric townhouses were developed and sold by BrightLeaf. Sanders owns one. His company’s niche since 2014 has been designing and building high-performance houses, including adding solar to offset energy use. Its homes are designated as zero-energy-ready as outlined by the U.S. Department of Energy. An all-electric home was a natural progression for the company.
For efficient cooling and heating of his demo homes, Sanders chose a Mitsubishi Electric multiposition air handler paired with a single-zone outdoor heat pump by Mitsubishi Electric and Trane. The unit accommodates colder climates and is designed to deliver up to 100% of its rated heating capacity at outdoor temperatures as low 5°F and maintain close to that performance in temperatures as low as -13°F. The unit performed well through a Chicago winter without a need to shift over to electric resistance operation. It features what is called hyper-heating inverter technology.
The BrightLeaf homes also feature one of two different hybrid electric (heat pump) water heaters: Rheem ProTerra or AO Smith Proline XE. With such systems, air is pulled in from the room, or units can be fed outdoor air. The air is then drawn down to a compressor to heat the water. Rheem’s product can be demand-response ready for participating utilities.
BrightLeaf demo homes also feature Energy Star-rated clothes washers and heat pump dryers, induction cook tops and 3-kilowatt photovoltaic panels. Built beyond standard code, the homes are projected to save 6,000 to 7,600 kilowatt-hours per year, offering an estimated savings of $970 per year on energy bills—before factoring in savings from generated solar power.
To successfully reach the full benefit of all-electric operation, Sanders builds the homes with high performance in mind.
“We support the home envelope with a high-performance insulation in the ceiling and attic, install triple-pane windows, develop a tight seal but with attention to ventilation and air filtration and we mask southern exposure windows, including adding overhangs if needed. In the cooler or colder months, the windows can take advantage of the Southern heat gain to passively heat the interior of the room(s),” he said.
Getting up to speed
Collaborating with other trades becomes important with all-electric homes, be it the EC with the HVAC contractor, the solar contractor and maybe the insulation contractor.
“Sizing for the electric is different too,” Sanders said. “You may bring in more electric-driven mechanics and appliances, but they may draw less load. So, you need to figure out your load calculations and home profile when sizing individual circuits for a heat pump, air handler, heat pump and hybrid water heater, or zoned HVAC devices.”
To learn more about all-electric homes, Margolies had a few suggestions.
“Manufacturers offer installer training for their equipment, utilities offer consumer-facing educational resources and Energy Star offers valuable information as well. There are also forums such as the Electrify Everything Facebook group that offers a place for contractors and homeowners to exchange technical insights and resources related to home and vehicle electrification. The Illinois Green Alliance is a great source of education, and ComEd has materials and resources for its Electric Homes New Construction program.”
Version 2.0 of all-electric homes is being queued up. Get ready.