Benefits from Low-NOx Omnibus and Advanced Clean Trucks (ACT) Adoption in 13 States and D.C. from 2020 to 2050Jiaoyan (Joey) Huang1, Jeff Houk1, Shih-Ying Chang1, Ray Minjares2
1Sonoma Technology, Petaluma, CA, USA
2International Council on Clean Transportation, San Francisco, CA, USA
Fifteen states and the District of Colombia (D.C.) have signed a memorandum of understanding (MOU) that calls for 100% of new medium-duty (MD) and heavy-duty (HD) truck and bus sales to be zero emission vehicles by 2050, with an interim target of 30% by 2030. The California Air Resources Board (CARB) has adopted the Advanced Clean Trucks (ACT) and California HD Vehicle Phase II regulations and has proposed the low-NOx Omnibus regulation to accelerate MD and HD electric vehicle penetration and reduce on-road mobile source emissions in California. To understand the benefits of adopting these regulations and the resulting zero emission truck targets in other states, we designed a systematic method to estimate NOx, PM2.5, and CO2 equivalent (CO2e) benefits from these regulations. We developed five scenarios that used county-level on-road data for the year 2017 from the U.S. Environmental Protection Agency (EPA)’s MOVES3 model and EPA’s Air QUAlity TimE Series Project (EQUATES), as well as data provided by state/local agencies, to model on-road emissions in 13 states (CO, CT, MA, MD, ME, NC, NJ, NY, OR, PA, RI, VT, WA) and D.C. for 2017, 2020, 2025, 2030, 2035, 2040, 2045, and 2050.
The first scenario that was developed was a business-as-usual (BAU) scenario. We then post-processed total on-road NOx, PM2.5, and CO2e emissions for each state and D.C. based on four additional scenarios: • Scenario 2: Dual Harmonization (ACT Rule, Low-NOx Omnibus Rule with urban buses) from model year (MY) 2025 • Scenario 3: Only ACT Rule from MY2025 • Scenario 4: Only Low-NOx Omnibus Rule with urban buses from MY2025 • Scenario 5: Only California Phase II GHG Standard from MY2025 (benefits of Phase 2 trailer rule only) Emissions rates from the U.S. Department of Energy’s Greenhouse Gases, Regulated Emissions, and Energy Use in Technologies Model (GREET) model were used to calculate the impact on upstream emissions from electric utilities and petroleum fuel production.
Compared to the BAU scenario, the typical NOx emission reduction (well-to-pump and vehicle emissions) is largest (25-30%) in scenario 2, and PM2.5 and CO2 emission reductions (well-to-pump and vehicle emissions) are 10-15% in scenarios 2 and 3. Some states had higher or lower reductions due to differences in fleet makeup and electrical grid emission rates. Detailed NOx, PM2.5, and CO2 emission reductions estimated for each state will be discussed, and the modeled future-year population of electric trucks will be presented. This information can help policymakers and scientists understand the benefits of zero-emission and low-NOx regulations.