Adoption Inequalities and Causal Relationship between Residential Electric Vehicle Chargers and Heat Pumps

The building sector has implemented code requirements to promote the adoption of all-electric heating systems and electric vehicle (EV)-ready in new construction, aligning with electrification goals. However, existing studies on adoption and equity indicators lack a comprehensive spatiotemporal perspective, impeding the evaluation of trends over time and across communities. To fill these gaps, this study investigates spatiotemporal inequalities and the link between EV charger and heat pump adoption, integrating community characteristics in Seattle using proposed inequality indices and multilevel vector autoregressive models. Key findings include a recent decrease in Gini inequalities for EV charger adoption and a consistent reduction in Gini inequalities for heat pump adoption over time. EV charger adoption demonstrates a stronger association with spatial inequality across tracts. Higher adoption variations over time for both technologies are observed in similar communities. Additionally, communities with higher EV charger adoption exhibit higher heat pump adoption, with only heat pump adoption Granger causing EV charger adoption within a community. Economic factors predict adoption patterns, linking higher income and income inequality to increased EV charger adoption but lower heat pump adoption. The findings suggest tailored strategies in building codes for promoting equitable clean energy technology implementation, considering technology-specific characteristics and spatial dimensions. Recognizing the causal links between technology adoptions is crucial for collaborating with grid operators, particularly in establishing building standards that prevent grid congestion. Aligning codes with clean energy intricacies promotes sustainable construction and urban environment. Striving for electrification in the building sector, the study explores clean energy technology adoption in Seattle. Positive trends emerge, with recent reductions in inequalities for EV chargers and consistent decreases for heat pumps over time. Notably, areas with higher EV charger adoption also experience increased heat pump adoption, with heat pump adoption leading to EV charger adoption. EV charger adoption demonstrates stronger spatial clustering, with higher adoption variations over time observed in similar communities for both technologies. Economic factors, like income, influence these patterns in the opposite direction to the technologies. To ensure a sustainable and fair transition, the research recommends tailored building code strategies, considering each technology's unique aspects and community spatial layouts. Recognizing the interconnections between these technologies is crucial for collaboration with grid operators and implementing building standards that prevent congestion. Aligning codes with clean energy intricacies fosters sustainability in construction and urban development, contributing to a greener future.