OptiFuel Systems will begin testing a prototype 5600 hp Total-Zero Renewable Natural Gas (RNG) Line Haul Locomotive and 2500 hp Total-Zero Powered Tender with 7,500 DGE (diesel gallon equivalent) capacity in January 2025. (Earlier post.)

The RNG-powered line haul locomotive produces 5100 hp of continuous power from Cummins RNG engines using OptiFuel’s Quick-Power technology with a peak power of 5600 hp with the standard LFP batterypack. Focused on sustainability, OptiFuel’s near-term, low risk, affordable Total-Zero RNGElectric Line Haul Locomotive will have zero well-to-wheel (WTW) NO_x and particulate matter (PM) criteria emissions and Negative Carbon Intensity (CI) while simultaneously improving fuel cost and operating range by 25%.

This solution aims to eliminate harmful pollutants that are released from diesel and renewable diesel engines that are detrimental to air quality and public health. 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 around $5.5 million and can be purchased or leased.

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 strength and weakness of battery-electric and hydrogen fuel cell hybrid locomotives.

However, 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 4500 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, OptiFuel’s President

OptiFuel is committed to spearheading the sustainable revolution with locomotives and refueling solutions that make fleet transitions affordable. Unique to OptiFuel’s locomotive designs is the use of modularity consisting of standard Quick Disconnect (QD) modules using standardized ISO corner locks.

Top. OptiFuel’s Modular, Total Zero Locomotive Supports Hydrogen or RNG Power Sources for Locomotives from 45 ft to 80 ft and 1000 to 5600 Horsepower. Bottom: OptiFuel’s 2500 hp Total-Zero Powered Tender uses the same modules as the locomotive and will carry 7,500 Diesel Gallon Equivalents (DGE) of RNG.

About 90% of the same components are used for our 1000 hp to 5600 hp RNG or hydrogen switchers and line haul locomotives and our RNG standard and powered tenders.

—Scott Myers

By using lower cost components in high volume production, the railroads can significantly reduce the cost to decarbonizing all 38,000 freight locomotives in the US over the next 25 years, a CAPEX cost that OptiFuel believes will be around $150 billion. However, that cost will be offset by significant annual operating cost savings thanks to lower fuel cost, lower maintenance cost, higher reliability, and increased system automation, allowing the railroads to increase market shares in moving goods across the US.

OptiFuel’s Refueling Solutions Plan provides for line haul operators to run trains in a consist 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 $8.5 billion in infrastructure expense to the railroads. This zero-cost approach is based upon the railroads buying RNG over a ten-year period of around $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.

OptiFuel Systems is the technical lead partnering with GTI Energy as the formal applicant to the Department of Energy. 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.