Breathe easy

Household electrification as a public health intervention to improve outdoor air quality.

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Executive Summary

Building electrification can help meet our climate goals while also improving outdoor air quality to create better health outcomes for communities across the country. Upgrading America’s existing household appliances to efficient electric machines comes with a host of positive outcomes. Electrification will improve outdoor air quality — leading to fewer premature deaths and reduced societal costs — all while reducing greenhouse gas emissions by 400 million metric tons, cutting energy bills by $60 billion every year, and creating more than one million jobs.1

In this report, we model the health benefits of electrifying America’s households through upgrading space heating, water heating, and clothes drying using heat pump technology. Collectively, these systems currently output more than half a million tons of fine particulate matter outdoors each year,2 through burning fossil fuels at home and electricity consumption from existing, inefficient electric appliances. We use building energy modeling, open-source data on air pollutants, and air quality modeling to quantify the potential for population health benefits of electrifying America’s households.

Our main findings include:

  • Electrifying America’s households would lead to 3,400 fewer premature deaths, 1,300 fewer hospital admissions and ER visits, 220,000 fewer asthma attacks, and 670,000 fewer days of reduced activity or missed work for Americans each year. These improved health outcomes resulting from household electrification translate to about $40 billion in health benefits every year.

  • Household electrification, combined with an electricity grid that is continuously getting cleaner, will reduce total pollution from fine particulate matter (PM2.5) and its precursors by 300,000 tons a year — the equivalent of taking 40 million cars off the road.3  

  • By making investments in residential electrification and passing policies that make it easier for households to choose these electric appliances, especially for households in disadvantaged and low- to moderate-income communities, policymakers can improve community health and reduce outdoor air pollution, in addition to reducing energy bills and lowering greenhouse gas emissions. 

Infographic titled “Annual health impacts from electrification of space heating, water heating, and clothes drying.” It has three columns: “Upgrade,” “Reduced premature mortality,” and “Associated health benefits.” The “Upgrade” column lists a heat pump, heat pump dryer, and heat pump water heater, with corresponding icons. The ‘”Reduced premature mortality” section shows a stacked bar graph indicating an estimated 3,400 premature deaths averted, due to transitioning to heat pump (largest impact), heat pump water heater (second-largest), and heat pump dryer (smallest). The “Associated health benefits’” section shows another stacked bar graph totaling $40 billion dollars, divided into heat pump (largest impact), heat pump water heater (second-largest), and heat pump dryer (smallest).

How electrification improves air quality and health

There is a knowledge gap around the impact of residential fossil fuel combustion on outdoor air quality, and a limited understanding of the cumulative pollution burden, health impacts, and costs of burning fossil fuels in common household appliances like furnaces, water heaters, and clothes dryers.4 As a result, full building electrification represents a largely untapped opportunity to improve outdoor air quality and community health.

About two-thirds of U.S. households use fossil fuels such as methane gas (commonly referred to as natural gas), propane, or fuel oil to heat their homes, heat their water, or dry their clothes.5 When fossil fuels are burned for these uses, they vent air pollutants such as ammonia, nitrogen oxides, sulfur dioxide, volatile organic compounds, and other particulates into the outside air. These air pollutants react in the atmosphere to form particulate matter less than 2.5 micrometers in diameter, which, collectively with primary fine particulate matter, are classified as PM2.5. Some of these pollutants — including primary PM2.5 and sulfur dioxide — are considered criteria air pollutants (CAP) by the Environmental Protection Agency (EPA). These are air pollutants for which acceptable levels of exposure can be determined and for which an ambient air quality standard has been set. They are subject to stringent regulations due to their adverse effects on public health.6

Infographic illustrating the health impacts of household fossil fuel use. On the left, three homes are depicted, two of them lit in red and emitting red pollutant particles. The caption reads “About two-thirds of U.S. households use fossil fuels such as methane gas, propane, or fuel oil to heat their homes, heat their water, or dry their clothes.” Arrows from the homes point to a large red particle in the center of the infographic labeled “PM 2.5,” representing fine particulate matter less than 2.5 micrometers in diameter, which results from burning fossil fuels. Arrows continue towards an illustration of human lungs affected by PM 2.5. Text below the lungs lists three health impacts: “Cardiac events,” “Premature death,” and “Respiratory issues.”

While power plants that use fuels such as gas and coal also emit PM2.5, these sources are centralized and, therefore, more easily addressed through the transition to clean energy generation. By combining that transition with electrifying households through the replacement of fossil fuel furnaces, water heaters, and dryers with efficient electric alternatives, we can completely remove the air pollutants emitted by households at their source. Replacing inefficient electric appliances like electric resistance heaters, water heaters, and dryers with highly efficient air source heat pumps can also reduce emissions at power plants because less electricity is needed to power these devices.

PM2.5 is especially dangerous because it can enter into a person’s lungs, and in some cases can even make its way into the bloodstream. Research has shown that breathing in particulate matter can lead to a range of negative health outcomes, including cardiac events, respiratory issues such as asthma, and even premature death. These negative health outcomes disproportionately impact a range of marginalized groups, including those with existing health issues, young children, seniors, minority groups, and those of lower socioeconomic status.7 By upgrading households to efficient electric appliances, we reduce the volume of PM2.5 in the air, and thus reduce the likelihood of adverse health events like premature deaths, asthma attacks, and heart attacks. Each avoided negative health outcome has an economic benefit associated with it. In this analysis, the most significant health benefit comes from avoided premature deaths.

Calculating the health benefits of electrification

We used building energy modeling compiled by the National Renewable Energy Laboratory (NREL) and released as part of their ResStock End Use Savings Shapes (EUSS) dataset to analyze the change in fuel-specific energy usage from a variety of residential electrification upgrades. The predicted change in energy usage was converted into changes in criteria air pollutant emissions and health impacts by calculating location and fuel-specific emissions factors and health benefit per ton of pollutant factors. 

Our analysis yields estimated reductions in outdoor air pollution and the health benefits of electrifying households, broken out at the county- and state-level. These estimates correspond to health benefits experienced over the entire continental U.S. from upgrades implemented in those specific geographic areas. 

We used data from the National Emissions Inventory (NEI) published by the EPA, the American Community Survey published by the U.S. Census Bureau, and state-level energy consumption estimates for the residential sector published by the Energy Information Administration (EIA) to calculate emissions factors for in-home fossil fuel usage, expressed in tons of pollutants per kilowatt-hour (kWh)-equivalent of energy consumption. To calculate similar emissions factors for residential electricity consumption, we used CAP emissions quantities reported by the 2020 NEI, annual electricity generation figures reported by the EIA, and NREL’s electric grid forecasting model, Cambium. The electricity emissions factors represent 15-year forward-looking average emissions factors (2023-2038), reflecting a pathway to a 95 percent decarbonized grid by 2050. 

Infographic titled “Methodology by the Numbers,” displaying three key statistics. On the left: “550,000: Building energy simulations output by EnergyPlus, a building energy simulation program developed by the Department of Energy (DOE),” accompanied by an icon of grids with house symbols. In the center: “95%: Decarbonized grid by 2050,” represented by a pie chart with the majority of the circle filled with homes connected by energy lines and lightning bolt icons. On the right: “’$11.5M: The value of statistical life used to quantify the societal benefit of reduced premature deaths,” illustrated with a seesaw balancing a dollar sign on one side and a heart on the other.

We then calculated a “benefit-per-ton” factor for each fuel, using the open-source air pollution transport model Intervention Model for Air Pollution (InMAP). Criteria air pollutant emissions from both residential fossil fuel combustion and electricity generation were input into InMAP to calculate the resulting air quality concentrations. Those concentrations were then converted into premature mortality impacts using the average of two widely used effect sizes from the epidemiological literature. To assign an economic valuation to the incidence of premature mortality, we multiplied the premature mortality estimate by a value of statistical life (VSL) figure of $11.5 million in 2024 dollars. To estimate other health endpoints, such as asthma cases and lost work days, we used the EPA’s COBRA tool,8 using the total changes in particulate emissions for residential fossil fuel combustion and electricity generation after full residential electrification (in this analysis defined as conversion to air source heat pumps, heat pump water heaters, and heat pump dryers).

To calculate the building-level impacts on health and outdoor air quality of various residential upgrades, we used ResStock’s End Use Savings Shape dataset. The dataset consists of approximately 550,000 building energy simulations output by EnergyPlus, a building energy simulation program developed by the Department of Energy (DOE).9 ResStock’s building energy simulations are meant to statistically represent the U.S. residential housing stock, conforming to known distributions of various housing characteristics such as square footage, primary heating fuel, housing typology, and many others. Each building energy simulation model represents approximately 242 households in the real world, and also pertains to a specific state, county, and Public Use Microdata Area (PUMA). In addition to modeling the baseline energy consumption of the U.S. housing stock, NREL used EnergyPlus to model the energy consumption of the U.S. housing stock under several electrification and efficiency retrofit scenarios such as installation of air source heat pumps, heat pump water heaters, and induction stoves. We supplemented these scenarios with our own modeled scenarios. The full list of upgrades we are considering in this analysis is provided below. Rewiring America created our own building energy modeling scenarios using the same 550,000 building energy models used in ResStock, with different heat pump specifications as described below. For calculating the nationwide impacts of full electrification, we included the heat pump, heat pump water heater, and heat pump dryer upgrades.10,11

Our analysis also does not model the health impacts of ground-level ozone formation from outdoor air pollutants.12 This may be included in future analysis.

Table 1: Electrification upgrade scenarios modeled in the analysis. The table has two columns: “Upgrade” and “Description.” Row 1: “Upgrade – Heat pump; Description – Retirement of existing heating/cooling and installation of an air-source heat pump with performance similar to a centrally-ducted, variable speed SEER 18 and 10 HSPF heat pump with electric resistance backup, or a ductless mini-split with SEER 18 and 10.5 HSPF, sized using HERS methodology and without a setpoint setback. Rewiring America modeled scenario.” Row 2: “Upgrade – Heat pump water heater; Description – Retirement of existing water heater and installation of a heat pump water heater with Uniform Energy Factor (UEF) 3.35–3.45 for all dwelling units with an existing water heater other than an electric tankless water heater.” Row 3: “Upgrade – Heat pump dryer; Description – Retirement of existing dryer (if applicable) and installation of a ventless heat pump dryer (CEF=5.2) for all dwelling units with non-electric dryers or less efficient electric dryers.”

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The health and air quality benefits of nationwide electrification

Fully electrifying America’s households will eliminate fossil fuel combustion within households, reduce air pollution by more than 300,000 tons of PM2.5 and its precursors every year, and lead to health benefits totaling about $40 billion each year. It will also prevent more than 3,400 premature deaths — that is as many people as are killed each year in the United States from distracted driving.13 

Comparison infographic with two side-by-side panels. On the left, a red box states: “3,308 annual deaths caused by distracted driving each year.” On the right, a blue box states: “3,400 annual premature deaths prevented through electrification each year.” A dotted line at the top aligns with the value 3,400 to visually emphasize the comparison.

The annual reduction in Primary PM2.5 and PM2.5 precursors from full electrification is presented in Table 2 below.

“Table 2: Annual pollution reduction (tons) from electrification of space heating, water heating, and clothes drying.” The table includes six columns: “Upgrade,” “NH₃,” “Primary PM₂.₅,” “SO₂,” “NOₓ,” and “VOC.” For heat pumps, the reductions are 41,583 tons of NH₃, 2,148 tons of Primary PM₂.₅, -28,494 tons of SO₂, 224,249 tons of NOₓ, and 12,414 tons of VOC. For heat pump water heaters, the reductions are 9,290 tons of NH₃, 1,089 tons of PM₂.₅, 3,632 tons of SO₂, 53,733 tons of NOₓ, and 2,926 tons of VOC. For heat pump dryers, the reductions are 560 tons of NH₃, 219 tons of PM₂.₅, 1,461 tons of SO₂, 4,320 tons of NOₓ, and 219 tons of VOC. The total reductions are 51,433 tons of NH₃, 3,456 tons of PM₂.₅, -23,401 tons of SO₂, 282,302 tons of NOₓ, and 15,559 tons of VOC.

Most pollutants have an overall net decrease of thousands of tons per year as a result of electrification. Space heating is currently the largest source of fossil fuel combustion within U.S. households. Converting all residential space heating to heat pumps would reduce the largest share of air pollution from in-home fossil fuel combustion, according to our modeling.

The net increase in sulfur dioxide emissions with full electrification of space heating is a result of the electricity grid simulated in the modeling still including generation from sources with high sulfur-dioxide emissions rates, such as coal. If the grid decarbonizes at a rate faster than the simulation included in this modeling, it may result in a net reduction of sulfur dioxide.

The cumulative impacts on premature mortality and the associated savings from the reduced air pollution are presented in Table 3 below.

“Table 3: Annual health impacts (approximate) from electrification of space heating, water heating, and clothes drying.” The table includes three columns: “Upgrade,” “Reduced premature mortality,” and “Associated health benefits.” For heat pumps, the impacts are approximately 2,600 reduced premature deaths and $30.4 billion in associated health benefits. For heat pump water heaters, the impacts are approximately 700 reduced premature deaths and $8.4 billion in associated health benefits. For heat pump dryers, the impacts are approximately 60 reduced premature deaths and $0.7 billion in associated health benefits. The total impact is approximately 3,400 reduced premature deaths and $40 billion in associated health benefits.

About three-quarters of the total avoided health impacts from electrification result from electrification of space heating, reflecting the high proportion of energy usage dedicated to heating and cooling in most homes.  

One of the most influential inputs in our modeling are the equipment specifications. For example, low-efficiency or improperly-sized heat pumps, which might rely on electric resistance to meet heating loads, would result in less pollution reduction, and therefore fewer health benefits. Our modeling uses a heat pump which is sized to minimize the use of electric resistance backup in order to minimize operating costs for the household. 

Infographic showing an outdoor heat pump unit with lightning bolt icons around it. Behind the heat pump is a semi-circular pie chart with a black section highlighting 75 percent. Below, text reads: “75: Percentage of electrification health benefits driven by electrifying space heating.”

Because our modeling includes the net impacts of reduced fossil fuel consumption and increased electricity demand, another important variable is the grid’s decarbonization schedule. We used Cambium’s modeling of a 95 percent carbon-free grid by 2050, which models an increase in solar and wind electricity production and an associated decrease in both greenhouse gases and air pollution. This modeling varies for each state. If certain states decarbonize faster than this model predicts, then we would expect an associated increase in pollution reductions, and larger-than-expected health benefits. 

By using NREL’s ResStock and building-level energy modeling for our analysis, we take into account the local climate, electric grid, baseline mortality rates, and housing stock characteristics, allowing us to estimate the health benefits and pollution impacts of electrifying specific households of interest in specific geographies. For example, retrofitting a large, fuel oil-heated household in Maine with a heat pump will have a different health benefit than installing that same heat pump in a small, electric resistance-heated household in Georgia because of differences in the local electric grid mix, heating, and cooling needs, climates, and fuel being replaced. Some of these interactions are illustrated in the tables below.

Figure 1 below shows the per-household societal health benefits of upgrading a home to a heat pump. We calculated these estimates by dividing the sum of the health benefits from upgrading households in that state by the number of households being upgraded.

The map shows how the combination of the electric grid composition, household characteristics, population density, and climate all play a role in determining the health benefits from electrification. Using ResStock’s building stock in combination with geography-specific emissions rates and benefit-per-ton factors means our modeling reflects the specificities of building decarbonization throughout the country.

  • In general, electrifying homes in the mid-Atlantic and Northeast, where there are substantial heating needs, high population density, and relatively clean electricity grids, leads to greater health benefits from reduced outdoor air pollution.

  • Health benefits are lower in states like Florida, where most homes meet their small heating requirements with electric resistance heating. While retrofitting these homes with heat pumps can lead to lower energy bills, the health benefits are primarily a product of requiring less electricity generation from the grid.  

  • In colder, northern states such as Maine, the lower health benefits are partly the product of lower population densities, where the outdoor air pollution from fossil fuels is dispersed over a larger, less populated area.

The type of fuel used in the appliance before an electric upgrade is another key factor in the avoided health impacts via electrification. Retrofitting homes heated with fuel oil and methane gas can lead to higher health savings because heating systems powered by these fuels are more polluting than propane or electric resistance heating systems. However, there are positive benefits to electrifying with heat pumps for all households, on average. The annual per household avoided tons of PM2.5 and its precursors and associated health savings are displayed in Table 4 below. 

Table 4: Annual per-household avoided pollution and health savings from heat pump installs in single-family households. The table has four columns: 'Original heating fuel being replaced,' 'Single family households,' 'Average PM₂.₅ and precursors avoided (tons),' and 'Average health benefits.' For fuel oil, 4,152,789 households avoid 2.00 tons of PM₂.₅ and gain $1,044 in health benefits. For methane gas, 43,806,585 households avoid 0.70 tons and gain $367. For propane, 4,230,755 households avoid 1.20 tons and gain $111. For electric resistance, 25,613,103 households avoid 0.39 tons and gain $107.

The positive return on 
 investment of electrification

To understand the potential of this data to inform policy outcomes, we can use an illustrative example analyzing the societal health benefits of federal electrification rebates and tax credits. As part of the Inflation Reduction Act passed in 2022, the federal government allocated almost $9 billion to home energy rebates to bring down the purchase price of electric appliances and home retrofits.14 High-Efficiency Electric Home Rebates (HEEHR) will cover 100 percent of the cost of heat pump installations for incomes 80 percent of Area Median Income (AMI) and below, and 50 percent of the cost for incomes 80 to 150 percent of AMI, up to an $8,000 cap. In addition to the direct consumer rebates, households that install qualifying heat pumps can also receive tax credits — up to 30 percent of the project costs — capped at $2,000. Tax credits are also available for other efficient electric equipment or home efficiency upgrades. 

Case study

Using New York as a case study, it becomes clear that the societal health benefits from improved outdoor air quality through electrification can exceed the costs of investments for these rebates and tax credits. New York was allocated $158,415,850 in HEEHR. We estimate that the cost of a heat pump for a low- or moderate-income single-family home in New York is about $21,800,15 so most households would be able to utilize the full value of the $8,000 cap. If the household had enough tax liability, they could also take advantage of the full tax credit value of $2,000. The health benefits from a single heat pump retrofit in New York for those same households would total about $1,576 per year, or more than $22,000 over the lifetime of a heat pump (about 14 years). This exceeds the total cost of the equipment, both before and after the rebates which may have spurred that heat pump installation. In addition, this does not take into account other household benefits such as the reduction of indoor air pollution, lower energy bills, and improved comfort. 

Cost-benefit analyses for future electrification rebates or investments should include the potential impacts of improved outdoor air quality, in addition to benefits in the forms of reduced carbon emissions, lower energy bills, and more comfortable households. 

Infographic with the title “Health benefits can exceed installation costs” shows three icons: The first, on left: a dollar sign and a doctor’s stethoscope icon is accompanied by the caption: “$22,000: Lifetime health benefits per heat pump in New York over 14 years.” The second, at center, has a map of the United States with a hand holding hundred dollar bills. The caption reads: “$8.8B: In rebates for home energy efficiency and electrification projects.” The third, on right, has a hand putting a coin into a piggy bank shaped like a home with a lightning bolt. The caption reads: “$2,000: Tax credits to households who install qualifying heat pumps.”

Conclusion

Residential building electrification is necessary to not only meet our ambitious climate goals and decarbonize our economy, but also to improve outdoor air quality and reduce premature deaths, hospitalizations, and other negative health events that result from the continued combustion of fossil fuels within our homes. State and local policymakers can unlock these benefits by approving further investments to make electrification more affordable and accessible for households across the country. This analysis can contribute to the electrification ecosystem through a few mechanisms: 

Advocates

Advocates promoting electrification can quantify the community health and air quality impacts of electrifying households in their jurisdictions. 

Policymakers

Policymakers can quantify the monetary health benefits from investments they make in electrification.

Healthcare providers and nonprofits

Healthcare providers and nonprofits can compare the efficacy of electrification in leading to improved health against other, more commonly used, public health interventions.

Communities and jurisdictions

Communities and jurisdictions out of compliance with outdoor air quality standards can quantify how building electrification proposals and policies can reduce emissions of key air pollutants.

While this modeling offers a more granular method of estimating the health benefits of home electrification, more analysis can be done to increase the scope of health benefits. In particular, future modeling may include:

Incorporating demographic information to understand how residential electrification can benefit low-income and disadvantaged communities.

The air quality and health benefits of electrifying America’s gas-powered cars and installing rooftop solar.

The benefits of reducing surface-level ozone, in addition to the PM2.5 and precursors benefits already modeled.

Accessing the data

To facilitate further analysis using this data and to make it possible for other electrification advocates to use the health impacts to make the case for residential electrification, all of the data is available through an API, available at https://api.rewiringamerica.org/. After applying for access, users can use the API to download the avoided pollutant volumes and health benefits for a number of different electrification upgrades, filtered for specific groups of housing according to a number of characteristics. 

Users can also explore the data in an interactive dashboard, publicly available and located here.

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Endnotes

  1. Herr, Alexandria et al. “Electrification that works: Jobs for a clean and healthy future.” Rewiring America. October 2024. https://a-us.storyblok.com/f/1014573/x/9a118b4539/electrification-that-works_rewiring-america-report.pdf

  2. We include particles less than 2.5 micrometers in diameter (PM2.5) and its precursors in this analysis.

  3. Based on analysis of the total volume of pollutants from on-road, light duty, gasoline vehicles, using EPA’s COBRA tool.

  4. “Literature Review on the Impacts of Residential Combustion Final Report.” American Lung Association, 10 July 2022. https://www.lung.org/getmedia/2786f983-d971-43ad-962b-8370c950cbd6/ICF_Impacts-of-Residential-Combustion_FINAL_071022.pdf

  5. Based on analysis of NREL’s ResStock dataset. 

  6. “NAAQS Table.” United States Environmental Protection Agency, 7 Feb. 2024. https://www.epa.gov/criteria-air-pollutants/naaqs-table

  7. “Health and Environmental Effects of Particulate Matter (PM).” United States Environmental Protection Agency, 16 Jul. 2024. https://www.epa.gov/criteria-air-pollutants/naaqs-table

  8. The tool is publicly available at https://cobra.epa.gov/

  9. The datasets are publicly available at https://resstock.nrel.gov/datasets

  10. While there will be some interaction effect between installation of a heat pump and heat pump water heater in the same home due to an increased heating load from the heat pump water heater in winter months (and decreased cooling load in summer months), we do not currently include that interaction in the full electrification estimate. 

  11. Since this report is focused on outdoor air quality, we do not include upgrades to indoor stoves in this analysis. 

  12. “Ground-level Ozone Basics”. United States Environmental Protection Agency, 14 May 2024. https://www.epa.gov/ground-level-ozone-pollution/ground-level-ozone-basics

  13. “Distracted Driving.” National Highway Traffic Safety Administration. Accessed October 24, 2024. https://www.nhtsa.gov/risky-driving/distracted-driving 

  14. “Biden-Harris Administration Announces State And Tribe Allocations For Home Energy Rebate Program.” Department of Energy, 2 Nov. 2022. https://www.energy.gov/articles/biden-harris-administration-announces-state-and-tribe-allocations-home-energy-rebate

  15. “Report: Upfront cost of home electrification.” Rewiring America, 1 Mar. 2024. https://www.rewiringamerica.org/research/home-electrification-cost-estimates

Appendix

Read more about the methodology and sources we used in this report:

Open appendix