Who Pays for a Clean Economy? Assessing the Household Accessibility of Residential Climate Action in Michigan

Abstract

Decarbonizing the U.S. residential sector is a complex problem whose solutions are entangled by intersectional societal dilemmas: climate change and economic disparity. Transitioning from combustion heat sources to electric-powered heat pumps for space heating is at the core of government policies and programs designed to reduce emissions in accordance with the Paris Agreement. Implementation of these plans will require significant market disruption in contractor services, manufacturer offerings, and customer choice, as well as an epic shift in the electricity sector to provide reliable, emissions-free power at affordable rates. The persistent inequality in access to quality housing in the U.S. could worsen because financial and institutional resources already available to promote new heating technology adoption have been shown to have lower rates of uptake in disadvantaged communities. This dissertation examines what stands in the way of equitable adoption of heat pumps in cold climates and tests ways of reducing disparate access across income. During a two-year field study, I analyzed utility bills, thermostat settings, and energy burdens as well as conducted energy assessments and provided retrofit recommendations for a sample of 51 households in Michigan, half below median income. I find that below-median income households would see a median energy burden rise from 6% to 10% if they shifted to electric heat pumps from natural gas. Weatherization could offset this increase, bringing burdens down to pre-electrification levels. However, median payback for weatherization is 24 years, making retrofits infeasible for lower-income households. Our results are indicative of an energy poverty trap that could hinder an equitable energy transition. I examined this trap using a qualitative analysis of the household experience with home energy audits. With interviews of participants conducted one year after they received audits, I characterized the steps they took towards home energy retrofits and the factors affecting their progress. I found that households with money hired a contractor and therefore had access to higher quality services. More often, high costs deterred households from even considering retrofits. Those who attempted do-it-yourself retrofits often failed to complete them upon facing unexpected installation challenges or underestimating the scarcity of their time. Next, I explored the hypothesis that the tradeoff between energy cost and space temperature is harsher for less efficient homes. I began by seeking to identify the homes in the National Renewable Energy Laboratory’s ResStock database of nationally representative archetypical homes that closely matched our sample and then assess the cost-temperature tradeoff for those homes. I found that it was impossible to find homes that matched both the actual consumption and building characteristics of the homes in our sample. I concluded ResStock is a useful tool for assessing aggregate regional energy, but it may obscure the dynamics of energy insecurity, like monthly energy costs. Finally, I propose an alternative to using only indoor temperatures as a proxy for occupant goals. I performed a literature review summarizing the state of practice for residential behavior modeling. I explored occupant objectives and strategies occupants deploy to achieve them with a mixed-methods analysis of thermostat management behavior, energy insecurity coping behavior, and their interaction using interview data and thermostat data. In conclusion, I proposed a research agenda for developing a new model capable of analyzing tradeoffs between household preference for energy cost, thermal comfort, and societal impact measured as greenhouse gas emissions and utility grid resiliency.