Impact of the Inflation Reduction Act and Carbon Capture on Transportation Electrification for a Net-Zero Western U.S. Grid

TL;DR

This paper investigates how the Inflation Reduction Act (IRA) incentives and Carbon Capture and Storage (CCS) technologies together influence transportation electrification in the Western U.S. using GCAM-USA scenarios that isolate IRA and CCS effects. It analyzes three metrics—transportation electrification rate, transportation fuel mix, and spatio-temporal charging loads—to show that IRA accelerates near-term electrification (through 2035) while CCS can suppress long-term electrification by enabling continued use of liquid fuels and ICE pathways. The findings highlight important policy-technology interactions and emphasize the need for sensitivity analyses to characterize each pathway’s potential contributions to a net-zero grid and economy. The results provide actionable insights for grid operators, EV infrastructure planning, and policy design under regionally varying circumstances and time horizons.

Abstract

The electrification of transportation is critical to mitigate Greenhouse Gas (GHG) emissions. The United States (U.S.) government's Inflation Reduction Act (IRA) of 2022 introduces policies to promote the electrification of transportation. In addition to electrifying transportation, clean energy technologies such as Carbon Capture and Storage (CCS) may play a major role in achieving a net-zero energy system. Utilizing scenarios simulated by the U.S. version of the Global Change Analysis Model (GCAM-USA), we analyze the individual and compound contributions of the IRA and CCS to reach a clean U.S. grid by 2035 and net-zero GHG emissions by 2050. We analyze the contributions based on three metrics: i) transportation electrification rate, ii) transportation fuel mix, and iii) spatio-temporal charging loads. Our findings indicate that the IRA significantly accelerates transportation electrification in the near-term (until 2035). In contrast, CCS technologies, by enabling the continued use of internal combustion vehicles while still advancing torward net-zero, potentially suppresses the rate of transportation electrification in the long-term. This study underscores how policy and technology innovation can interact and sensitivity studies with different combination are essential to characterize the potential contributions of each to the transportation electrification.

Figures (9)

• Figure 1: Combined transportation electrification rate for LDVs, MDVs, and HDVs: Percentage of EV energy and EV fleet across scenarios and over time in the Western U.S. Interconnection.
• Figure 2: Transportation electrification, expressed as the percentage of electric vehicle fleet, for LDVs, MDVs, and HDVs over time and across scenarios in the Western U.S. Interconnection.
• Figure 3: Transportation fuel mix over years for each of the three scenarios in the Western U.S. interconnection.
• Figure 4: State-wise transportation fuel mix in the Western U.S. interconnection in 2035 and 2050 across the scenarios. The x-axis labels represent transportation fuel energy in EJ consumed by 10 million population. Different color scales are used for each fuel type to accurately capture and reflect the variation in their magnitudes.
• Figure 5: Hourly time-series of total transportation electric load in the Western U.S. Interconnection for analyzing the impact of the IRA policies in 2035.