In the United States (US), OptiFuel Systems LLC has announced that it will begin testing a prototype 5,600 hp Total-Zero Renewable Natural Gas (RNG) Line Haul Locomotive and 2,500 hp Total-Zero Powered Tender with 7,500 DGE (diesel gallon equivalent) capacity, in January 2025.
OptiFuel Systems is a solution provider designing and manufacturing “Total-Zero” emission products and services in the hard-to-abate transportation and industrial markets, specifically in rail, marine, and power generation.
OptiFuel works as a systems integrator with strategic partners to engineer innovative technology that is low-risk and modular with flexible fuel options consisting of affordable renewable natural gas (RNG) and hydrogen fuels.
The RNG-powered line-haul locomotive produces 5,100 hp of continuous power from zero-emission Cummins RNG engines using OptiFuel’s “Quick-Power” technology with a peak power of 5,600 hp with the standard LFP battery pack.
This innovative solution aims to eliminate harmful pollutants that are released from diesel and renewable diesel engines that are detrimental to air quality and public health.
As the designer and builder of the fuel cell, hydrogen storage, and battery modules for Sierra Northern Railway’s (SERA) hydrogen hybrid switcher locomotives, OptiFuel is uniquely qualified to understand the strengths and weakness of battery-electric and hydrogen fuel cell hybrid locomotives, said Scott Myers, President of OptiFuel Systems.
According to the company, its near-term, low-risk, affordable Total-Zero RNG Electric Line Haul Locomotive will have zero Well-to-Wheel (WTW) nitrogen oxides (NOx) and particulate matter (PM) criteria emissions and Negative Carbon Intensity (CI) while simultaneously improving fuel cost and operating range by 25 percent.
We now believe that RNG is the preferred path to zero-emission line haul locomotives and tenders due to the physics of energy storage, overall operating cost, operating risk, fuel availability and cost over the next 20 years. A 4,500 hp line-haul locomotive requires continuous high power for extended hours, something that neither battery-electric nor hydrogen fuel cell hybrid line-haul locomotive solutions will be able to do, Scott Myers explained.
Extensive test program
Partially funded with a Department of Energy (DOE) grant, the program will perform pre-production testing at the Federal Railroad Administration’s (FRA) Transportation Technology Center (TTC) for 12 months.
In 2026, OptiFuel will start a 2-year, 1-million-mile test program with ten pre-production 5600 hp RNG line haul locomotives and five 10,000 DGE RNG tenders operating around the US.
Upon successful completion, plans are to begin full production in 2028. The RNG line-haul locomotive is estimated to be priced at around US$5.5 million and can be purchased or leased.
Utilize modularity and scale economy
Unique to OptiFuel’s locomotive designs is the use of modularity consisting of standard Quick Disconnect (QD) modules using standardized ISO corner locks.
About 90 percent of the same components are used for our 1,000 hp to 5,600 hp RNG or hydrogen switchers and line haul locomotives and our RNG standard and powered tenders, said Scott Myers.
By using lower-cost components in high-volume production, the railroads can significantly reduce the cost of decarbonizing all 38,000 freight locomotives in the US over the next 25 years, a CAPEX cost that OptiFuel believes will be around US$150 billion.
However, that cost will be offset by significant annual operating cost savings thanks to lower fuel costs, lower maintenance costs, higher reliability, and increased system automation, allowing the railroads to increase market shares in moving goods across the US.
Refueling- and fuel station infrastructure plan
A comprehensive refueling services and fuel station infrastructure plan addresses not only the capital expenditure challenges related to refueling but also resolves the logistics and planning burden of combined diesel-RNG fleets.
It provides for line haul operators to run trains in a consistent with both old (diesel) and new (RNG) locomotives without changes to routes, distance between stops, refueling time, or capital expense budgets.
This diesel-RNG locomotive integrated refueling system approach is already in service at the Indiana Harbor Belt Railroad (IHB) outside of Chicago.
The estimated 3,000 RNG tenders and associated 60 RNG locomotive and tender refueling stations required by the Class 1 locomotives around the US will be provided at no cost – offsetting an estimated US$8.5 billion in infrastructure expense to the railroads.
This zero-cost approach is based upon the railroads buying RNG over ten years of around US$2.00 a Diesel Gallon Equivalent (DGE). The RNG volume and price will be secured by long-term contracts connected to specific RNG-production sites with stable, known production volumes.
Instead of imposing limitations and constraints, OptiFuel equipment empowers railroad customers to reliably enhance operations, regain valuable competitive advantage, and take back market share lost to trucking through dependable and improved services.
The robustness and sustainability of the rail network safeguard the integrity of the US supply chain, facilitate the efficient transportation of goods across the country, and serve as a pivotal driver of economic health.
OptiFuel Systems is the technical lead partnering with GTI Energy as the formal applicant to the Department of Energy’s Office of Energy Efficiency and Renewable Energy (EERE) under the Vehicles Technology Office (VTO).
Other technical partners are Cummins, BAE Systems, Luxfer Gas Cylinders, TMV Control Systems Inc., ENSCO, CAF Group, New York Air Brake, and Powerhouse, a Marmon Rail Company.