based on Ye, X. et al. Nat. Energy https://doi.org/10.1038/s41560-025-01845-2 (2025)

The policy problem

Millions of US households experience energy insecurity, which can appear as households struggling to pay energy bills, sacrificing essential needs (for example food or medicine), or living in homes with unsafe or uncomfortable indoor temperatures. Switching to clean energy technologies like heat pumps can help families use energy more safely and efficiently. Heat pumps provide both heating and cooling and can reduce the need for people to limit their energy use due to high energy bills, as they operate more efficiently. To support their uptake, federal and state programmes now offer help with financing heat pumps in homes across the country. However, it remains unclear how, and to what extent, heat pumps alleviate energy insecurity. Over the course of the energy transition, policymakers need evidence to assess whether heat pumps effectively improve household well-being and contribute to energy equity, particularly for low-income and vulnerable populations.

The findings

Using electricity records from 8,656 households in Phoenix, Arizona, we find that households with heat pumps begin cooling their homes when outdoor temperatures are 0.996 °C (1.8 °F) lower than those without. Despite earlier cooling capabilities, these households also use 0.48 kWh less electricity daily per degree increase in outdoor temperature, translating to an average saving of US$116 in the summer months. These savings matter even more for low-income families, who may save up to 18% of their seasonal energy bills. Heat pumps help narrow the energy gap between high- and low-income households (that is, the energy equity gap) by making cooling more affordable and indoor environments more comfortable. These findings indicate the potential for heat pumps to contribute to reduced energy insecurity and improve energy equity by enabling more comfortable and affordable cooling.

The study

Focusing on the Phoenix metropolitan area of Arizona, our analysis draws from two datasets from a major local utility, hourly electricity records, and a detailed residential survey with information on household demographics, energy technologies, and housing characteristics. We utilize the thermal comfort indicator (cooling balance point and cooling slope) to assess the energy insecurity status of each household. We obtain these indicators by fitting piece-wise linear relationships between electricity usage and weather conditions. We then compared these comfort patterns between households with and without heat pumps (Fig. 1), while controlling for income, race, and housing characteristics. This approach allows us to assess how adopting new energy technologies like heat pumps might reduce energy insecurity, especially among vulnerable groups.

Fig. 1: Estimated effects of heat pump adoption across income groups.
figure 1

The figure presents results from a random effects regression model assessing the impact of heat pump adoption on thermal comfort indicators across eight income levels. Estimated effects on cooling balance points (CBP, in °C) and cooling slopes (CS, in kWh per °C) are shown, with points representing coefficients and horizontal bars denoting 95% confidence intervals. More negative values indicate earlier cooling activation or lower electricity use per degree of temperature increase. Figure adapted from Ye, X. et al. Nat. Energy https://doi.org/10.1038/s41560-025-01845-2 (2025).

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