Future River Environmental Sustainability

Environmental Impact of River Freight

River cargo movement is environmentally efficient compared to moving goods by other modes.  The Environmental Protection Agency (EPA) estimates mobile source emission factors for several hazardous air pollutants, including hydrocarbons (HC), carbon monoxide (CO), nitrogen oxides (NOx), particulate matter (PM), and carbon dioxide (CO2). The emission comparison between inland towing, rail, and truck transportation shows that fewer emissions are generated by moving products on America’s inland navigation system. It is estimated that if waterborne freight were diverted to highways, it would require two more inches of asphalt added to the pavement of 126,000 lane miles of intercity interstate.

(Source: Texas Transportation Institute. A Modal Comparison of Freight Transportation Effects on the General Public. Texas A&M University. (2017).)

Future Waterway Technologies

The maritime industry is investing in port automation and autonomous vessels, primarily for ocean borne cargo, as a means to streamline operations and reduce their environmental footprint. Technology advancements related to riverports should be considered to not only improve operations and expand the regional maritime cargo mix, but reduce the environmental impact of river cargo shipping.

Alternative Fuels

Nearly all river shipping transport vessels and onshore material handling and transport equipment are powered by diesel fuel. The future use of alternative fuels could reduce the emissions of an industry that already has a relatively low air contaminant footprint.

Biofuels are those derived from organic means to fuel internal combustion engines. The most common are ethanol and biodiesel. These can be blended with petroleum diesel to reduce CO2 emissions. Widespread future use will depend on the development of biofuels from non-food-based materials such as wastes, cellulosic biomass, and algae-based resources.  

The transportation industry sees natural gas as a transitional fuel to bridge the adoption lag time between fossil fuels and fully electric. Unlike other modes, the use of natural gas is low in the maritime industry. And it is expected to remain so due to the low energy density of compressed natural gas and the cost and infrastructure requirements for cryogenic liquid natural gas (LNG). Because barges travel long distances without refueling, the current diesel configuration provides efficiencies that these other fuels are unable to realize.

Truck manufacturers such as Toyota and Volvo have developed and are testing zero-emissions trucks using hydrogen electric power, which could be adapted for waterborne vessels. A hydrogen fuel cell vehicle generates its own electricity from the hydrogen onboard, eliminating the need to be charged from an external source. In addition to eliminating emissions (hydrogen emits water vapor), these vehicles have travel ranges similar to those of existing diesel fleets.

The benefit of hydrogen vehicles is that they are fueled similarly to diesel, as both are pumped into on-board tanks. Operators can utilize existing fueling station locations and infrastructure along the inland waterway network.

Green ammonia (NH₃) is an option being explored for large payload maritime shipping. The ammonia (used for fertilizers and other applications) is currently shipped via water. It has a significant energy density that can be stored at ambient temperatures, and used in internal combustion engines, replacing diesel fuel.

(Source: The VINCI Group. Leonard website. Foresight/Energy Transition: Air and Maritime Mobility. (October 11, 2021).)

The global company TECO 2030 is working across the maritime sector to develop new green technologies. The company’s Power Barge is a concept for a floating zero-emission power supply for running ships and tugs using hydrogen-fed, port infrastructure. The concept allows major benefits in terms of increased safety, reduced operational costs, reduced land area use, increased flexibility while also eliminating harmful emissions.

Barge Electrification

Electrified barges run on battery packs built into the barges themselves. They can be used in the same way as current tug and multiple barge operations, by replacing one of the barges with one that provides electricity to the electric-powered tug. When depleted, the battery packs are replaced with fully charged containers. This battery swapping method requires a network of open access charging points that allows the quick exchange of depleted batteries for ones fully charged. Current electric barge models have travel ranges between 30 and 60 miles per batch of charging container packs.

Given the nature of the inland waterway industry, adoption of electric barges will be driven primarily by the private sector. Infrastructure necessary for electric intermodal hub vehicles will be similar to those identified for other forms of vehicle electrification: