By: Cary Weiner, October 11th, 2018
This is Part 1 of a 2-part series on all electric homes. This post focuses on the financial costs and benefits of going all-electric, while Part 2 will focus on the carbon costs and benefits.
As electric vehicle sales continue to soar, there’s also been a growing buzz in the sustainable energy world about fully electrifying buildings. The theory is that we can electrify almost everything and then produce that electricity with clean, cheap, renewable electricity from wind, solar, hydro, and battery storage. It’s a compelling argument on the surface, so we thought we’d dig a little deeper into costs and benefits to fully electrify homes.
The chart above compares annual household energy costs for homes heated with natural gas (conventional), propane, and electric air source heat pumps (HP). It also includes a comparison of energy costs for energy efficient homes with those same heating fuels. As you can see, homes heated with natural gas are the cheapest to operate, followed by homes heated by air source heat pumps, and then homes heated by propane. But it is also interesting to note that homes that invest in both energy efficiency (i.e. air sealing and insulating) AND air source heat pumps can see savings compared to conventional homes.
The question remains whether the investment in both efficiency and heat pumps is worth it, and that answer depends on what you value. Heating with electricity allows you to avoid the safety concerns associated with indoor combustion of gas or propane. Electric heat pumps not only heat your home, but they also provide cooling. In addition, heating/cooling with electricity allows you to offset 100% of your home energy use with renewable energy in order to decrease your carbon footprint, which will be covered in Part 2 of this exploration.
- Conventional/propane = 80% efficient furnace, 0.6 EF water heater, 10 SEER air conditioner
- Heat pump (HP) = 10 HSPF, 18 SEER, 2.2 SEF
- $0.60/therm, $0.11/kWh, $2.30/gal. (propane)
- “30% EE” refers to homes that use 30% less energy than standard homes