Table 1.

Summary of database assumptions to represent the U.S. energy system

Category	Description
Fuel Supply	Fossil fuel prices are specified exogenously from projections in the 2022 Energy Information Administration (EIA) Annual Energy Outlook’s Reference Oil Price case for Net-Zero runs No-Policy runs45. A supply curve constructed from the 2016 Billion-Ton Report61 reflects biomass costs and supply. There are no constraints placed on the availability of other fuels.
Electric	Costs and performance characteristics for new electric generators from the “Moderate-Market” scenario of the Annual Technology Baseline 202162.
Transportation	The transportation sector is divided into four modes: road, rail, air, and water. The demands, efficiencies, and costs for these modes are drawn from sources including the U.S. Environmental Protection Agency’s (EPA) nine-region market allocation (MARKAL) database59, Net-Zero America study11, and the National Renewable Energy Laboratory’s (NREL) Electrification Futures Study (EFS)63.
Commercial	The service demands in the commercial sector are adopted from NREL EFS63. The techno-economic parameters of the end-use technology are from the EIA64. Existing capacity of technologies are from the EPA’s MARKAL database58,59.
Residential	The service demands in the residential sector are from NREL EFS63. The techno-economic parameters of the end-use technology are from the EIA64. Existing capacity of technologies are from the EPA MARKAL database58,59.
Industrial	End-use demands in the industrial sector are aggregated based on the North American Industry Classification System. Demands are derived from the Manufacturing Energy Consumption Survey65. A set of common industrial processes represents the energy consumption in the manufacturing sector to account for the heterogeneity across the industrial sector. These industrial processes include 1) process heating, 2) conventional boiler use, 3) combined heat and power or co-generation systems, 4) machine drives, 5) facility heating ventilation and air conditioning systems, 6) process cooling and refrigeration and 7) a catch-all ‘other’ energy use category.
Hydrogen	Cost and efficiency assumptions from the International Energy Agency Future of Hydrogen Report47.
Regions	The United States is divided into nine regions, as shown in Supplementary Fig. 1.
CCS	Bio-Energy Carbon Capture and Sequestration data are drawn from averages of Integrated Assessment Models66. Powerplant Carbon Capture and Sequestration data comes from PowerGenome46.
Fischer-Tropsch Fuels	The capability of synthesizing Fischer-Tropsch fuels using H2 and CO2 is included in the model based on published techno-economic parameters67.
Direct Air Capture	Capital and operating costs are from the literature68. The transport of CO2 to sequestration sites is modeled using a cost curve, which has eight steps11.
Renewable Resources and Transmission Build Out	Renewables data are compiled using PowerGenome46, an open-source tool that allows users to create input datasets for power system capacity expansion models. Annual hourly variable renewables capacity factor data for a representative year (2012) are used to develop representative intra-annual time slices. Historical capacity factors of existing capacity are obtained from EIA, while data for potential new generators are obtained from datasets developed by Vibrant Clean Energy.
Inflation Reduction Act (IRA) Provisions	The database incorporates the IRA provisions, including the investment and production tax credits for renewable electricity generators, carbon capture, and use/sequestration, the production tax credit for existing nuclear capacity, the clean hydrogen production tax credit, and tax credits for passenger and commercial vehicles (Detailed in Supplementary Method 4 and Supplemental Table 1-4).
Discount Rate	Social discount rate is 5%. Technology-specific discount rates are from PowerGenome.