Decarbonizing Workboats - Top 5 Things to Consider

Key technologies and operational strategies to reduce carbon emissions in the workboat and tugboat sector

The Elliott Bay Design Group-designed methanol-fueled towboat M/V Hydrogen One. Photo: Elliott Bay Design Group

As maritime regulations tighten and port decarbonization initiatives accelerate, workboat operators face growing pressure to cut emissions without compromising operational flexibility. From hybrid-electric propulsion to shoreside power and fuel innovation, here are five essential considerations for emissions reduction across the workboat fleet, along with practical examples already in motion.

What fuels work best for hybrid or zero-emission systems?

Fuel choice is the foundation of any low-emission strategy. While battery-electric propulsion may suit short-haul or passenger vessels, workboats operating in inland or coastal settings often demand greater range, energy density, and bunkering simplicity.

Methanol is emerging as a promising candidate. It’s already available in over 125 ports worldwide and is compatible with existing infrastructure. When reformed into hydrogen onboard, it becomes a clean fuel source for PEM fuel cells without the need for high-pressure or cryogenic storage. Methanol’s global availability, growing renewable production capacity, and compatibility with existing maritime logistics make it one of the most accessible near-term fuels for decarbonization.

e1 Marine’s methanol-to-hydrogen reformers generate fuel-cell-grade hydrogen onboard and on demand, eliminating the need for complex hydrogen bunkering or storage. This fuel supply solution enables efficient integration into hybrid-electric or fuel cell propulsion systems across a range of vessel types.

Why do vessel size and power profile matter?

Workboats are not one-size-fits-all. Vessels under 2,000 GT, such as tugs, towboats, and inland craft, typically require hotel loads in the 50-150 kW range, much lower than the multi-megawatt demands of cruise ships. Yet they still demand high torque, rapid acceleration, and consistent energy delivery, especially when operating in dynamic port or inland environments.

However, smaller vessels are also constrained in terms of available engine room and deck space, meaning retrofits must be lightweight and space efficient. This makes them poorly suited to pure battery propulsion or large OPS connections which are often oversized for these requirements. That’s where compact, lightweight onboard generation systems come in.

e1 Marine’s M-Series and S-Series reformers deliver flexible onboard hydrogen production for vessels with limited space. When paired with fuel cells, batteries, and energy storage, these systems can support zero-emission hotel loads and hybrid propulsion, either underway or at berth, without compromising vessel layout or payload.

How far can you go between refuelling? 

Unlike large ocean-going ships, workboats typically operate on shorter, regionally defined routes, but they still need dependable energy for extended operations. Energy systems must be optimised for range, refuelling simplicity, and operational uptime, especially in areas with limited bunkering infrastructure.

Hydrogen One - a towboat currently under development by Maritime Partners - is a prime example of this model in action. Powered by e1 Marine’s onboard methanol reformers, the vessel uses hydrogen generated on demand to feed PEM fuel cells, which work in tandem with battery energy storage to deliver fully electric, zero-combustion propulsion.

With a range of over 550 miles between refuelling stops, Hydrogen One is designed for inland waterway operations such as the Mississippi River system. The project demonstrates the real-world viability of modular hydrogen systems designed around workboat operational profiles.

What if the port doesn’t have shore power?

Onshore Power Supply (OPS), or cold ironing, is often prioritised for cruise ships or large container vessels with multi-megawatt power demands. But many smaller terminals, especially those servicing workboats, lack the grid capacity to support full-scale OPS installations. In fact, the European Sea Ports Organisation (ESPO) has cited grid limitations and permitting delays as the most common barriers to OPS rollout.

This presents a major operational risk for all-electric vessels that depend on shore power to recharge. Without guaranteed grid access, these vessels may face delays, reduced service availability, or the need to revert to auxiliary engines - undermining emissions gains and commercial reliability.

Rather than waiting for grid-based infrastructure to catch up, e1 Marine’s solution brings clean power generation back onboard the vessel. By converting methanol into hydrogen onboard, vessels can generate clean electricity for hotel loads and propulsion without relying on limited or congested grid infrastructure.

This not only enables compliance at berth without cold ironing but also reduces strain on the grid, allowing ports to prioritise fixed grid power for larger vessels while enabling smaller ships to operate independently. It’s a flexible, scalable way to relieve infrastructure pressure while accelerating emissions reductions today.

How can operators stay compliant as rules evolve?

From FuelEU Maritime to the IMO’s proposed carbon pricing mechanism, regulatory pressure is rising fast, even for smaller vessels. Offshore and general cargo ships between 400-5,000 GT are already required to report emissions under the EU MRV, and their inclusion in the EU ETS is under review for 2026. That means workboat operators must start planning now for a more tightly regulated operating environment.

e1 Marine’s onboard methanol-to-hydrogen systems offer a practical path to near-term compliance without waiting on portside infrastructure or emerging fuel supply chains. By generating hydrogen onboard using methanol, a fuel already approved by the IMO and widely available at scale, operators can immediately reduce GHG and pollutant emissions in line with regulatory targets. Emissions reductions independently validated by Thetius showed 10-27% GHG reduction using grey methanol, around 50% with a green/grey blend, and up to 85% with green methanol, alongside a 99%+ reduction in NOₓ, PM, CO, and hydrocarbon emissions compared to diesel engines.

Because these systems are modular, compact, and scalable, they fit within the constraints of smaller vessels while aligning with evolving international rules. Importantly, they also provide a future-proof foundation: as renewable methanol becomes more accessible, the same system architecture can be used to meet stricter carbon intensity thresholds and zero-emission requirements - without costly redesigns or retrofits.

Final thought

Decarbonizing the workboat sector requires practical, scalable systems that work in diverse operational environments. From fuel sourcing and vessel design to infrastructure and compliance, every decision shapes the path toward zero emissions.

e1 Marine’s reformer technology is not a propulsion system in itself, but a clean, reliable fuel solution that enables hybrid and electric propulsion across a diverse range of workboats. Alongside partners, e1 Marine is helping the sector move beyond concept and into action.