Skip to main content
Man at dock in life vest

Hybrid-electric Towboat Makes Waves into the Future

Kirby Corporation’s Green Diamond hybrid-electric towboat is a first-of-its-kind. It is a quieter vessel with 60% reduced emissions, while being equal in power to a traditional towboat.

William Patterson, better known as Billy, has been on the water for over 30 years. His job is more than just a job; it is meaningful to his life. He started working at marinas and ports for his father when he was a young man, progressing to fishing boats, scuba boats, dive boats, captaining, and then finally working on towboats.

Towing vessels is a tough job. The crew of Green Diamond are on the water for 20 days out of the month and spend more time on the vessel than they do at home. The vessel is their second home, and work becomes a family affair, from days moving barges through the Houston Ship Channel to breaking bread together.

Looking back at Billy’s history on the water, and the different vessels he’s captained, never in his wildest dreams did he think he’d be navigating through Port of Houston waterways on a hybrid powered towboat like Green Diamond.

“Around the port, the other vessels thought the towboat would never work, and it was just for show. Then as we started moving barges every day, they saw us moving so much, now they really respect Green Diamond.”

William Patterson
Towboat at dock in the channel

Decarbonizing the shipping industry, one tow at a time

The Houston Ship Channel is a site to see. It’s estimated 22,000 ships move through the channel annually. It’s a choreographed dance of vessels of all sizes, moving cargo of all types, including consumer goods, fuel supplies, and shipping containers through the waters. The towboats that push some of those vessels need power, which has traditionally required diesel fuel - until now. Kirby Corporation (Kirby) introduced the first US plug-in hybrid-electric inland towing vessel, Green Diamond. It is a first-of-its-kind vessel that runs on both battery and traditional engines, partially powered by 100% renewable electricity* supplied by Shell Energy Solutions, backed by Green-e® certified renewable energy certificates, which charge the vessel’s battery systems. The result is a quieter vessel with 60% reduced emissions**, while being equal in power to a traditional towboat.

Green Diamond first catches your eye, then your ear

Two batteries power the 74x30-foot towing vessel for the equivalent of 1,800 horsepower. For reference, a typical car on the road today has between 180 and 200 horsepower. Operationally, the towboat runs on electric batteries two-thirds of the time, only using generators about ten percent of the time, and the rest is shore power, which is the land-based power supply. The most noticeable difference is that when battery power is on, the rumbling sound of a traditional engine is missing. Once the towboat pulls into the dock after its shift, it normally takes between four and six hours to charge, similar to charging an electric vehicle.

The questions the crew of Green Diamond first faced by other operators on the water have been answered by seeing the towboat’s powerful and energy efficient design at work. The operational results and crew delivery have gained respect among their traditional peers. Hybrid or fully electric towboats could be the wave of the future; Billy and his team are onboard.

Man steering a towboat

“It's nice to be on the cutting edge and see what the future holds with the technology we're applying to the marine industry.”

William Patterson

Frequently asked questions

Share this story on social media

*Shell Energy Solutions TX PUCT #10174

**Since entering service in April 2024, Green Diamond's diesel engines have averaged 53 hours of runtime per month compared to a conventional vessel’s average 300 hours of runtime per month, resulting in an estimated 60% reduction in emissions compared to a conventional vessel.