Assumptions used in the California heat pump analysis

This fact sheet details the technical and financial assumptions used in an analysis of heat pump adoption in California, specifying system efficiencies, energy load sources, and utility rates for electricity, natural gas, and propane.

• The analysis defines specific rated efficiencies for current and new heating and cooling systems: current gas or propane furnaces are rated at 85% AFUE and current AC at 13 SEER2, while new Air Source Heat Pumps (ASHP) are rated at 16 SEER2 with HSPF2 ratings of 8 (IECC climates 2-4) or 9 (IECC climates 5-6).
• Energy load profiles for typical single-family homes were sourced from the National Renewable Energy Laboratory’s (NREL) ResStock. Hourly efficiencies for ASHPs in IECC climates 5 and 6 were derived from a subset of 100 common units in the Northeast Energy Efficiency Partnerships’ database, with electric resistance heating covering unmet loads.
• The analysis utilizes specific utility rates for California, including natural gas rates for SCG, PG&E, and SDG&E, and national-average propane rates of $2.51/gallon. Electricity rates are based on specific time-of-use (TOU) plans from providers including SCE, PG&E, SDG&E, LADWP, SMUD, and Imperial Residential, with different plans applied before and after the installation of ASHP or HPWH.

APA

RMI (n.d.). Assumptions used in the California heat pump analysis. https://rmi.org/wp-content/uploads/2025/04/Assumptions-used-in-the-California-heat-pump-analysis.pdf

Chicago

RMI. Assumptions used in the California heat pump analysis. n.d. https://rmi.org/wp-content/uploads/2025/04/Assumptions-used-in-the-California-heat-pump-analysis.pdf.

Wikipedia

{{cite report |author=RMI |title=Assumptions used in the California heat pump analysis |url=https://rmi.org/wp-content/uploads/2025/04/Assumptions-used-in-the-California-heat-pump-analysis.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{rmindassumptions, author = {{RMI}}, title = {{Assumptions used in the California heat pump analysis}}, institution = {RMI}, url = {https://rmi.org/wp-content/uploads/2025/04/Assumptions-used-in-the-California-heat-pump-analysis.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }