Lower Bills, Better Grids: Heat Pump Benefits for Homes Heating with Electric Resistance

This fact sheet details the technical assumptions used to analyze the benefits of heat pumps over electric resistance heating. It specifies efficiency ratings for ASHPs and HPWHs, explains the use of EIA and NREL data to create home archetypes across US climate zones, and describes the methodology for calculating hourly efficiency and electric volumetric prices.

• The analysis utilizes specific rated efficiency benchmarks for heating and cooling systems: electric resistance space heat is set at 1.0 AFUE, air conditioners at 15.2 SEER2, and air-source heat pumps (ASHP) at 16 SEER2/9 HSPF2 for ducted systems and 17 SEER2/9.5 HSPF2 for ductless systems. For water heating, electric resistance is rated at 0.93 UEF, while heat pump water heaters (HPWH) are rated at 3.45 UEF with 310% effective efficiency in efficiency mode.
• Home archetypes and energy load profiles were derived from the US Energy Information Administration’s (EIA) 2020 Residential Energy Consumption (RECS) microdata and the National Renewable Energy Laboratory’s (NREL) ResStock. Archetypes were grouped by variables including building type, year, space heating fuel and equipment, air conditioning type, and household income, with building stock shares determined by state and climate zone.
• Hourly efficiency for ASHPs and HPWHs was estimated using performance curves against TMY3 temperature data and ambient temperatures based on common water heater locations. Cold climate ASHP curves were based on a subset of 100 common units from the Northeast Energy Efficiency Partnerships’ database, sized to meet nearly all heating load with limited supplemental electric resistance.

APA

RMI (n.d.). Lower Bills, Better Grids: Heat Pump Benefits for Homes Heating with Electric Resistance. https://rmi.org/wp-content/uploads/2026/03/ER-to-HP-Article-Assumptions.pdf

Chicago

RMI. Lower Bills, Better Grids: Heat Pump Benefits for Homes Heating with Electric Resistance. n.d. https://rmi.org/wp-content/uploads/2026/03/ER-to-HP-Article-Assumptions.pdf.

Wikipedia

{{cite report |author=RMI |title=Lower Bills, Better Grids: Heat Pump Benefits for Homes Heating with Electric Resistance |url=https://rmi.org/wp-content/uploads/2026/03/ER-to-HP-Article-Assumptions.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{rmindlower, author = {{RMI}}, title = {{Lower Bills, Better Grids: Heat Pump Benefits for Homes Heating with Electric Resistance}}, institution = {RMI}, url = {https://rmi.org/wp-content/uploads/2026/03/ER-to-HP-Article-Assumptions.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }