EPLO turbocharger upgrades are helping older vessels join the decarbonization journey

With a reported reduction of only 14.2%,¹ as of December 2024 – only 0.2% more than in 2022 – and the European Union adding impetus through carbon pricing and penalties in its Emissions Trading System (ETS)² and FuelEU Maritime³ regulations, shipping companies are looking for every means of speeding up decarbonization efforts. Accelleron’s EPLO turbocharger upgrades are giving shipping operators a fast and affordable way of cutting emissions in existing fleets, putting a spate of older vessels on the path to decarbonization.

The past five years have seen incredible development in the marine industry, with technology suppliers, engine designers, shipyards, and shipping companies coming together to fulfil the IMO’s 2050 net zero ambition. While future carbon-neutral fuels will be critical to reaching net zero, a report commissioned by the IMO Future Fuels and Technology Project “Shipping GHG emissions 2030: Analysis of the Maximum Technical Abatement Potential” shows that the technologies already exist to reach the IMO’s first major emissions checkpoint in 2030. The report further asserts that a reduction in global shipping emissions of 28-47% by 2030, (vs. 2008) is technically feasible. 

While a quarter of that abatement would depend on more expensive future carbon-neutral fuels, and another quarter on the installation of wind-assisted propulsion and other technologies, fully half could be accomplished through lower sailing speeds and other operational measures.⁴

Tackling the fifty percent of operational emissions cuts

Matthias Reichmann, Senior Engine Expert and Product Manager for EPLO Upgrades at Accelleron, says, “Our Engine Part Load Optimization (EPLO) program falls into the fast and easy operational category. EPLO is one of the quick fixes for cutting emissions in the existing fleet. Within an average port stay of one or two days, we can combine turbocharging component upgrades with engine derating (limiting sailing speeds), to cut fuel consumption and lower emissions by an average of 3%, in some cases more.”

Lowering power to lower fuel cost and emissions

Reichmann continues, “Ships built 10 or 15 years ago were designed to run most efficiently at high power. Of course, maximum power equals maximum fuel consumption, and maximum emissions, which was acceptable, when operating profiles were different,” says Reichmann.

“Now, the industry has an urgent mandate to cut emissions by 20-30% by 2030. That’s not a lot of time. The fastest way to do it is to reduce the power output. Even taking into account temporary power increases to navigate in storms and icy conditions, we can safely recalibrate the turbocharger and engine to run most efficiently at a lower % of their maximum continuous rating. That brings substantial fuel savings and emissions cuts.”

And it's a safe bet for operators. Whether ships are running on conventional or transitional fuels and need to improve efficiency and emissions ratings, or they are running on expensive, future carbon-neutral fuel like methanol, ammonia, or hydrogen and need to get every drop of energy out of those fuels, fuel efficiency demands will continue to rise. “There’s no way we’ll see the return to higher speeds and higher fuel consumption rates,” says Reichmann.

Vast potential in the existing global fleet

This “quick fix” could enable a vast pool of existing ships to join the decarbonization journey now. With an average vessel age of 12.6 years ⁵ in the global fleet, and a backlog of new ship orders, thousands of ships currently in operation could cut emissions virtually overnight, to meet new sustainability regulations and contribute to the 2030 IMO target. 

Return on investment includes asset value preservation

Such retrofit solutions are also affordable. “Ship operators are going to break even on their investment within 3 years, at the latest, just through operational savings,” says Reichmann. “Really, though, the ROI goes far beyond that. Using EPLO and similar programs, we can help shipping companies avoid the premature retirement of ships that are only midway through their potential lifespans, giving them another 10 or more years of operation under increasingly stringent sustainability regulations.”

The nuts and bolts of EPLO

“Every EPLO project is individually tailored,” Reichmann explains. “There is no single out-of-the-box solution, and each project will be adapted to the engine and the ship.”

However, one part of EPLO modifications is the same for all ships – keeping the original turbocharger. “We do not change the turbocharger itself,” says Reichmann. “We keep the same turbocharger casing and frame size; the housing flanges and other external parts also remain the same. It’s only the internal parts where we make the changes, from the compressor wheel to turbine shaft and blades, nozzle ring and diffuser.”

Upgrading components is quicker than a regular service visit, with no need to clean or reassemble older parts. The fact that changes are limited to turbocharger internals means that EPLO projects can be conducted during routine servicing schedules, rather than requiring a visit to a dry dock.

Accelleron upgrades turbocharger components when implementing EPLO, but also works with turnkey partners (OEM or engine builders) for additional engine modifications. This could include anything from changing injectors to modifying engine exhaust valve timing or changing the compression of the engine. Such changes also require optimization of injection timing for optimal combustion, which enables a significant increase in main engine efficiency over the lower power range.

CII rating up in two days

Reichmann highlights Solvang’s LPG tanker, Clipper Hebe, as an example of how EPLO can give an entirely new life to aging ships, explaining, “The operator of the Clipper Hebe needed to maintain a minimum speed of 14 knots to meet their agreed charter rates. They tried to simply limit their engine power to comply with EEXI regulations. Unfortunately, that made the ship unable to reach 14 knots, so they turned to Accelleron for help.”

Reichman worked with Solvang on a tailored solution that combined a turbocharger component upgrade to maximize efficiency at lower power, and a propellor upgrade, which allowed the Clipper Hebe to reach 16 knots.

“We were able to improve the Clipper Hebe’s Carbon Intensity Indicator (CII) rating, giving it another decade of life, at least. Plus, by combining EPLO and the propellor upgrade, we were able to generate a massive 25% fuel saving.”

EPLO gains momentum as a quick decarbonization solution

With increasing regulatory pressures, the demand for EPLO and similar upgrades is rising rapidly. Accelleron’s upgrades have grown in popularity year on year, saving customers tens of thousands of tons of CO₂.⁶

Accelleron and HD Hyundai Marine Solution together conducted a recent EPLO retrofit on car and truck carrier MV Morning Concert, enabling the vessel to comply with the Energy Efficiency Existing Ship Index (EEXI), CII, EU ETS, and other emissions reduction regulations.

The MV Morning Concert was only the first of four car carriers from Wallenius Wilhelmsen to undergo EPLO retrofits. It’s also just one of the vessels to benefit from Accelleron’s new long-term agreement with HD Hyundai Marine Solutions.

Chief Operations Officer at Höegh Autoliners Sebjørn Dahl says, “Sustainability and emissions reductions are at the core of Höegh Autoliners’ strategy. This joint project with Accelleron and Hanwha shows excellent results and is an example of decarbonization in practice.”