Supporting Data and Results for "Characterizing uncertainties in residential electrification: Financial feasibility, climate impacts, and health outcomes"

Article Abstract: 

Low-to-moderate-income (LMI) families in the United States face disproportionately high energy costs due to inefficient housing and systemic underinvestment, conditions that stem in part from discriminatory housing policies (e.g., redlining and exclusionary zoning). With uncertain federal support, state and local authorities need evidence-based strategies for equitable electrification initiatives. This study enhances the Tradeoff Analysis of Residential retrofits for Energy equity (TARE) model for retrofit adoption potential, considering both effects from the Inflation Reduction Act (IRA) and a comprehensive societal impact assessment.

Heat pump water heaters demonstrate nearly universal adoption potential, with LMI adoption reaching 96-99% for delivered fuel users. Air-source heat pump (ASHP) retrofits show fuel-specific adoption trends in LMI households, ranging from 2% (natural gas) to 67% (fuel oil), with diminishing returns for enclosure upgrades. Climate impacts were evaluated using three social cost of carbon bounds, while health co-benefits were quantified using six methodologies combining reduced-complexity models (InMAP, EASIUR, AP2) with two concentration-response functions. Electrifying space heating in 85-96% of households would improve public health through reduced air pollution exposure. Furthermore, accounting for societal benefits from reduced greenhouse gas emissions increases economically viable retrofits from 16% (private costs only) to 53-67% (including monetized climate benefits).

Results suggest that decision-makers should prioritize heat pump water heaters as key electrification policy entry points and design fuel-specific approaches for space heating. The expanded framework provides decision-makers with quantitative tools for equitable energy transition planning and can be adapted locally to expedite technical assistance for historically underserved populations.