Options for Railroad Electrification and Decarbonization
The Congressional Research Service (CRS) report titled “Options for Railroad Electrification and Decarbonization,” authored by Ben Goldman and dated July 5, 2024, provides an insightful analysis of the current state and potential future paths for reducing emissions within the U.S. railroad sector. Railroads, traditionally more energy-efficient and less polluting compared to other transport modes, still face significant challenges due to their reliance on diesel engines. This dependency results in harmful emissions, particularly in rail yards, and contributes to greenhouse gas accumulation. Consequently, there is growing congressional interest in mitigating these emissions as part of broader national environmental goals.
The report highlights several strategies the railroad industry is exploring to cut emissions. These range from mature technologies like wayside electric power to emerging solutions such as battery or hydrogen power. The California Air Resources Board’s (CARB) In-Use Locomotive Rule, adopted in April 2023, marks a significant regulatory shift. This rule mandates a rapid transition to zero-emission propulsion technologies, with stringent requirements on idling times, operational age limits, and the integration of zero-emission configurations for both passenger and freight locomotives. The financial implications of this rule are substantial, with CARB estimating a $15.9 billion cost over 25 years. This expense may translate into higher shipping rates and poses significant challenges for smaller railroads reliant on older locomotives.
One of the principal alternatives discussed is wayside electric power. This technology involves electric trains powered by overhead wires or electrified rails, which, although costly to implement, offer reduced maintenance and increased operational efficiency. However, the high infrastructure costs and limited applicability for freight railroads, which dominate U.S. rail usage, present significant barriers. Additionally, while electric trains may still consume power generated from fossil fuels, their operational benefits, such as higher speeds and quicker acceleration, make them attractive for passenger services.
Battery and battery-hybrid power options are also considered. Pure battery-powered trains and hybrid diesel-electric battery systems present a minimal need for new infrastructure but are hampered by battery weight and limited operational range. Despite recent advancements, the practical use of pure battery power remains confined to short-haul operations due to the necessity of frequent charging stations.
Hydrogen power emerges as a promising yet nascent technology. Hydrogen fuel cells generate electricity with water and heat as by-products, offering a clean energy alternative. Despite the current greenhouse gas emissions associated with industrial hydrogen production, hydrogen-powered locomotives benefit from rapid refueling compared to battery systems. The Federal Railroad Administration (FRA) and Sandia National Laboratories have recognized hydrogen fuel cells’ potential, though their deployment is currently limited.
Federal support for railroad electrification and decarbonization has been sporadic. Freight railroads, being private enterprises, generally do not receive federal funding, though there have been instances of financial assistance for low-emission technologies. The Infrastructure Investment and Jobs Act of 2021 and the Inflation Reduction Act of 2022 have indirectly supported such initiatives, though primarily for highway applications. Recent federal appropriations and grants have facilitated the research, development, and procurement of battery-electric locomotives and hybrid systems.
The report underscores the complexity and financial burden of transitioning the U.S. railroad industry to cleaner technologies. While California’s stringent regulations could drive innovation and broader adoption of zero-emission locomotives, the nationwide implications and economic impacts require careful consideration and substantial investment.