Shipowners Under Pressure: Reducing Fuel Costs, Emissions and Compliance Risks Without Costly Retrofits

How existing fleets can become more efficient in an increasingly regulated maritime world

The international shipping industry is facing one of the most demanding transformations in its history. For decades, the primary challenge for shipowners was relatively clear: operate vessels safely, reliably and economically. Today, this task has become significantly more complex. Shipowners must continue to ensure schedule reliability, cargo safety, crew management and technical performance — while also demonstrating compliance with increasingly strict environmental, emissions and energy-efficiency requirements.

The economic pressure is substantial. Fuel remains one of the largest operating cost blocks in shipping. At the same time, every tonne of CO₂, every inefficient operating profile and every deviation from emissions requirements can create financial, regulatory and reputational risk. What used to be a technical efficiency question has become a strategic management issue: How can existing fleets reduce fuel consumption and emissions without costly retrofits, long dry-dock periods or operational disruption?

Maritime professionals reviewing operational data on deck to improve fuel efficiency, reduce emissions, and optimize existing fleet performance.

The new reality: cost reduction and emissions reduction must happen together

Shipping remains the backbone of global trade. However, it is also a relevant contributor to global greenhouse gas emissions. According to IMO-related reporting, international shipping accounts for roughly 2–3% of global greenhouse gas emissions, depending on the year and methodology used. This makes maritime decarbonisation not only an environmental issue, but also a regulatory, commercial and financial priority.

For shipowners, this means that emissions reduction is no longer optional. It increasingly affects charter agreements, financing conditions, insurance assessments, port requirements, classification processes and customer expectations. A fleet that cannot demonstrate a credible pathway to lower fuel consumption and reduced emissions may face higher costs, weaker ratings and reduced competitiveness over time.

The challenge is particularly difficult because a large part of the global fleet cannot simply be replaced in the short term. Ships have long operating lifecycles. Alternative fuels, new propulsion systems and major retrofit solutions will play an important role, but they are often capital-intensive, infrastructure-dependent and operationally complex. Shipowners therefore need not only long-term decarbonisation strategies, but also practical efficiency measures that can be applied to existing vessels.

Global climate goals: IMO is raising the pressure

At international level, the International Maritime Organization, IMO, is the central regulatory body. The 2023 IMO GHG Strategy sets the ambition for international shipping to reach net-zero greenhouse gas emissions by or around 2050. It also includes indicative checkpoints: at least 20%, striving for 30%, reduction by 2030, and at least 70%, striving for 80%, reduction by 2040, compared with 2008 levels.

These targets are not only political statements. They are increasingly translated into concrete technical and operational requirements. Two of the most relevant instruments are EEXI, the Energy Efficiency Existing Ship Index, and CII, the Carbon Intensity Indicator. The amendments to MARPOL Annex VI entered into force on 1 November 2022, and the EEXI and CII certification requirements came into effect on 1 January 2023. The first annual reporting took place in 2023, with initial ratings issued in 2024.

EEXI evaluates the technical energy efficiency of existing vessels, while CII measures operational carbon intensity in real operation. This means that not only ship design matters, but also daily performance: routing, speed, engine condition, maintenance, fuel management, weather routing, hull condition and every measure that reduces fuel consumption are becoming increasingly relevant for compliance.

EU regulation: EU ETS, FuelEU Maritime and MRV are changing the cost structure

In Europe, the pressure is even more direct. Since 2024, maritime transport has been included in the EU Emissions Trading System, EU ETS. Shipping companies must surrender their first allowances by 30 September 2025 for emissions reported in 2024. The phase-in schedule is 40% coverage for 2024 emissions, 70% for 2025 emissions and 100% from 2026 emissions onward.

In practice, this means that CO₂ has become a direct cost factor for shipping. Every tonne of fuel saved can reduce not only bunker costs, but also emissions certificate costs. Energy efficiency is therefore no longer only an operational target — it is also a carbon cost strategy.

In addition, FuelEU Maritime has applied in full since 1 January 2025. The regulation promotes renewable and low-carbon fuels and clean energy technologies, while setting greenhouse gas intensity reduction requirements for energy used on board ships trading within the EU or European Economic Area.

The EU MRV system also plays a key role by requiring monitoring, reporting and verification of emissions from ships operating on EU-related voyages. RINA describes EU MRV as a mandatory monitoring, reporting and verification system for ships above 5,000 gross tonnage travelling to or from EU ports, regardless of flag, subject to defined exemptions.

RINA, DNV and classification societies: turning regulation into practical compliance

It is important to distinguish between regulators and classification societies. Core requirements are created by IMO, the EU, flag states, port state control and national legislation. Classification societies such as RINA and DNV do not create these regulations, but they play an essential role in making them assessable, verifiable and practically manageable for shipowners.

RINA offers CII and EEXI consulting services to support shipowners and ship management companies on their decarbonisation pathway, especially in understanding MARPOL amendments and keeping up with regulatory updates.  RINA also provides EU ETS verification services and states that it is accredited by ACCREDIA and ESYD for verification of MRV monitoring plans, ship-level and company-level emission reports and related compliance documentation.

DNV describes the EU ETS as a cap-and-trade system that brings carbon pricing into maritime operations. It also highlights that the system applies to cargo and passenger ships above 5,000 GT from 2024, initially covers CO₂ and will include methane and nitrous oxide from 2026.  DNV further identifies EU ETS and FuelEU Maritime as key operational regulatory milestones for 2025–2026.

For shipowners, this means that every efficiency measure must be more than technically attractive. It must fit into a reliable compliance, monitoring and documentation framework.

Country-specific and regional requirements increase complexity

Shipowners must also navigate regional and national requirements. MARPOL Annex VI sets limits on sulphur oxides and nitrogen oxides from ship exhausts and allows the creation of Emission Control Areas with stricter standards for SOx, NOx and particulate matter.  The Mediterranean Sea officially became a SOx Emission Control Area under MARPOL Annex VI on 1 May 2025, limiting sulphur content in fuel oil for ships operating in the area to 0.1%.

In the United States, MARPOL Annex VI is implemented through the Act to Prevent Pollution from Ships. The EPA states that Annex VI applies to US-flagged ships wherever located and to non-US flagged ships operating in US waters.  The United Kingdom has also been moving its maritime emissions framework forward, including changes around UK MRV and the planned expansion of the UK Emissions Trading Scheme to maritime emissions.

The result is a fragmented but tightening regulatory environment. Requirements can vary depending on route, flag, port, ship type and trading area. This increases the value of flexible, low-disruption efficiency measures that can support existing fleets without requiring fundamental technical changes.

The operational dilemma for shipowners

Many decarbonisation solutions are technically promising but difficult to implement quickly. Alternative fuels such as green methanol, ammonia, biofuels and synthetic fuels may become important in the long term. However, they can be expensive, unevenly available, infrastructure-dependent and uncertain in terms of supply, certification and lifecycle emissions.

Technical retrofits — such as new propulsion systems, exhaust treatment, wind-assisted propulsion, battery systems or major engine modifications — may also contribute to emissions reduction. But they often require high capital expenditure, engineering work, approvals, integration, shipyard time and operational interruption.

This creates the central dilemma for many shipowners: they must act now, but they cannot immediately rebuild or replace every vessel.

The key commercial question is therefore:

Which measures can help reduce fuel consumption and emissions in existing fleets in the short term — without costly technical intervention and without disrupting operations?

nanoEFX: a pragmatic efficiency approach for existing fleets

In this environment, nanoEFX is positioned as a complementary efficiency solution for engines operating with fossil fuels. The product is designed to support more efficient combustion and thereby help reduce fuel consumption and emissions — without mechanical modification of the engine, without intervention in the propulsion system and without structural changes to the vessel.

The strategic advantage lies in the simplicity of the approach. nanoEFX is not positioned as a replacement for broader decarbonisation strategies. Rather, it can be considered as an additional efficiency measure for existing engines and fleets. For shipowners, this is highly relevant: not every solution needs to be a large-scale capital project. Some measures create value precisely because they are easy to test, simple to integrate and operationally low-disruption.

For fleet managers, technical directors and compliance officers, nanoEFX may be relevant for three main reasons. First, any reduction in fuel consumption can contribute directly to lower operating costs. Second, more efficient combustion can support emissions reduction efforts. Third, such a measure can complement wider efficiency programmes connected to CII improvement, SEEMP measures, ESG reporting and fleet optimisation.

Marine engineers inspecting the engine room to identify practical efficiency improvements and emissions reductions without major retrofits.

Not a replacement for compliance — but a practical building block

From a professional perspective, nanoEFX should not be presented as a standalone solution to all regulatory requirements. Shipowners must continue to comply with applicable IMO, EU ETS, FuelEU Maritime, MRV, UK, MARPOL Annex VI, ECA, flag state, port state and classification requirements.

The relevant point is different: nanoEFX can be integrated as a low-threshold efficiency building block within a broader fleet efficiency strategy. Such a strategy may include route optimisation, hull and propeller cleaning, fuel monitoring, speed management, improved maintenance intervals, crew training, digital performance analytics and additional technologies that support cleaner combustion.

Within this broader framework, nanoEFX addresses a practical need: improving the efficiency of existing engines in existing vessels during ongoing operations.

Shipping must become cleaner — but the transition must remain economically realistic

The question is no longer whether shipping must reduce emissions. That decision has already been made by regulators, markets and customers. The real question is how emissions reduction can be implemented in a way that is economically viable, technically safe and operationally realistic.

IMO targets, EEXI, CII, EU ETS, FuelEU Maritime, MRV systems, ECAs and national regulations are increasing the pressure on shipowners. At the same time, fuel costs remain one of the most important operating cost factors in shipping. Whoever reduces fuel consumption reduces costs. Whoever reduces emissions improves regulatory and commercial positioning.

In this context, nanoEFX can be understood as a pragmatic efficiency measure for existing fleets. It is designed to support cleaner and more efficient combustion, reduce fuel consumption and lower emissions — without costly retrofits, mechanical intervention or operational downtime.

Cleaner combustion. Lower fuel costs. Reduced emissions. Existing fleets made more efficient — without costly retrofits.