Host Kevin O’Connor meets with building engineer Ross Trethewey and master electrician Heath Eastman to discuss whole-home electrification, and whether it’s always the best move for homeowners.
What is Whole-Home Electrification?
Whole-home electrification is the practice of turning all of a home’s appliances and devices over to electric-only. This includes the heating and cooling systems as well as kitchen appliances, but it also includes installing electric vehicle chargers in new homes, preparing for the possibility of the homeowner having an EV.
As This Old House Magazine noted, “A century after electricity started brightening most U.S. homes and powering pop-up toasters, a second electrification of American life has begun—this one aimed at reducing the use of fossil fuels.” The shift is being driven by induction cooktops seeing drastic increases in market share, several cities banning new residential natural-gas hookups, and all-climate heat-pump technology that now makes heating and cooling with electricity less costly than using natural gas.
Where Does the Power Come From?
One thing to consider is that, while electricity seems eco-friendly, all of our power doesn’t come from renewable sources. For example, major sources of electricity include fossil-burning operations such as coal and nuclear power plants.
While we’re working towards renewable sources, we’re not quite there yet. According to the EIA, as of February 2024, renewables made up 21.4% of all electric generation in the US, so even though it has grown substantially, it still only represents about 1/5.
Today’s Common Fuel Sources
In homes that haven’t yet gone through whole-home electrification, the common fuel sources come from fossil fuels. This includes propane, natural gas, and oil. With these sources, there is always a risk of back-drafting, pipe leaks, carbon monoxide poisoning, and other dangers. Some might also use eco-friendlier heat pumps, which use electricity to pull heat from the air or geothermal sources instead of fossil fuels, resulting in fewer dangers and risks and less environmental impact.
Which is Cheaper?
Homeowners need to do their homework to determine whether electrification will actually be cheaper for their needs. The challenge is that the units of measurement used for the different sources vary:
- Electricity is quantified in price per kilowatt hour
- Oil and propane are quantified in price per gallon
- Natural gas is quantified in price per therm
Historically, the cost ranking of fuel sources has remained fairly consistent. As Ross explained on Ask This Old House: “Historically, electric baseboard has been the most expensive system to heat a building, and followed up by your propane and oil furnaces would be your next. And then gas and heat pumps are kind of there in kind of the next category.” When host Kevin O’Connor asked whether that order has held over the years, Ross confirmed: “Just about, yeah, and so it’s always very important to make sure that we are installing these heat pumps to lower the operating cost of that building.”
Pro Tip: Ross, a heating and energy expert featured on Ask This Old House, recommends using a “levelized price per kilowatt hour” chart to put all fuel sources on the same playing field. By knowing your electric utility rate and the average efficiency of your heating system over the season, you can make a true apples-to-apples comparison across fuel types.
Ross’s Levelized Chart
To help homeowners determine the affordability of their decisions, they assembled a chart of levelized prices. Homeowners who know the efficiency of their heat pump over the heating season and their utility rate per kWh can compare the actual cost or net price per kWh.
The levelized chart also converts the output of natural gas, propane, and oil into kilowatt hours (kWh). This allows homeowners to compare rates, helping find the most affordable option. Spoiler alert: Many times, it’s natural gas. That being said, natural gas is usually only available in densely populated urban areas, so it’s not an option for all homeowners.
Newer Homes Can Rewrite the Rules
With newer homes, it may be possible to find that electrification is the way to go. Installing solar on the roof as well as having high-performance building envelope coupled with heat pumps may lead to lower rates and lower electricity usage. This is a synergistic approach, as the home’s heating and cooling can be powered from the solar array on the roof. This is how homes achieve “net zero” where the solar system generates the same or more electricity than the house uses over the course of a year.
Existing Homes Might Need a Combination of Fuels
While electrification sounds great, existing homes with specific heating and cooling infrastructure might not be completely compatible with heat pumps. When that’s the case, it may require a dual-fuel, hybrid system, which runs primarily on the heat pump system but utilizes the existing fossil fuel-burning system to supplement heating on colder days when the heat pump can’t keep up.
Resources
Ross’s Energy Cost Comparison Sheet
U.S. Energy Information Administration’s average utility prices around the country:
