Air clean up
DNV Maritime CEO Cristina Saenz de Santa Maria explains why energy-efficiency measures offer the fastest, most cost-effective route to maritime decarbonisation while alternative fuels continue to mature.
In a shipping industry facing regulatory change, geopolitical uncertainty and commercial pressure, keeping decarbonisation plans on course is becoming increasingly challenging. With alternative marine fuels still years away from widespread adoption, what should shipowners prioritise today?
For Cristina Saenz de Santa Maria, CEO Maritime at DNV, the answer is clear: energy efficiency.
As the maritime industry works towards the IMO's net-zero emissions ambition by 2050, energy-efficiency measures represent the most immediate opportunity to reduce greenhouse gas (GHG) emissions, lower fuel costs and strengthen commercial resilience across today's global fleet.
Cristina Saenz de Santa Maria, CEO Maritime at DNVWith the theme of Nor-Shipping 2027 – NEXT highlighting the industry's future direction, Saenz de Santa Maria believes the next step is also the most practical: improve the efficiency of vessels already in operation while low-GHG fuels and emerging technologies continue to scale.
Saenz de Santa Maria points to DNV's growing portfolio of research, including its Maritime Forecast to 2050, alongside white papers covering methanol, biomethane, onboard carbon capture, shore power and vessel energy efficiency.
Together, these reports help shipowners navigate an increasingly complex landscape shaped by evolving regulations, fuel uncertainty and decarbonisation targets.
While she believes every alternative fuel and technology has an important role to play in shipping's long-term transition, widespread deployment will take time.
Low-GHG fuels such as green ammonia and green methanol remain in limited supply, and much of the world's merchant fleet is not yet equipped to use them.
That makes energy efficiency the most scalable solution available today.
Around 90% of the global fleet still operates on conventional fuels, creating a significant opportunity to reduce emissions immediately through operational improvements, retrofit technologies and capital investments.
According to DNV's Maritime Forecast to 2050 (2025 edition), energy-efficiency measures could reduce fuel consumption by up to 16% by 2030—equivalent to removing the emissions of approximately 55,000 smaller vessels from the global fleet.
"In my view, energy-efficiency measures have the potential to become one of the most scalable decarbonisation levers," says Saenz de Santa Maria.
Although energy-efficiency technologies are often viewed primarily as regulatory compliance tools, Saenz de Santa Maria argues they offer a far broader business case.
Using less fuel not only cuts emissions but also reduces operating costs and exposure to volatile fuel markets.
"In today's geopolitical environment, improved energy efficiency reduces exposure to fuel price volatility because you simply need less of whatever fuel you're burning," she explains.
Just as importantly, fluctuating fuel prices can dramatically improve the return on investment for retrofit projects.
DNV recently modelled a Very Large Crude Carrier (VLCC) fitted with a scrubber that was considering a shaft generator retrofit.
At fuel prices of around USD 670 per tonne in February 2026, the investment payback period was approximately 18 years.
Only two months later, with fuel prices climbing to around USD 1,600 per tonne, the payback period had fallen to just eight years.
The example illustrates how rapidly changing fuel prices can transform investment decisions.
The commercial benefits become even greater when energy-efficiency improvements are combined with regulations such as FuelEU Maritime and the EU Emissions Trading System (EU ETS).
DNV analysed a Capesize bulk carrier operating between Brazil and Rotterdam after achieving a 20% improvement in energy efficiency.
When operating on marine gas oil at current prices, the efficiency gain generated savings of approximately USD 60,000 per voyage.
When using green methanol, however, the savings increased to around USD 300,000 per voyage.
"That isn't a marginal difference," says Saenz de Santa Maria. "It's a strategic advantage—and it's available today."
Despite growing regulatory pressure, Saenz de Santa Maria warns against implementing isolated measures simply to satisfy short-term compliance requirements.
Instead, she advocates a strategic, data-driven approach.
"The most common pattern we see is companies selecting individual measures in response to immediate compliance pressure. It is also the least effective."
Successful decarbonisation begins with understanding the current performance of every vessel.
Reliable operational data enables owners to develop tailored roadmaps based on vessel design, trading patterns, commercial structure and long-term investment priorities.
"There is no universal playbook," she says.
Her advice to shipowners is straightforward:
Shipping's transition to net zero will require a combination of alternative fuels, new technologies and operational improvements—but companies should not wait for future fuel availability before acting.
Energy-efficiency measures deliver immediate emissions reductions while building a stronger foundation for future decarbonisation investments.
Companies that postpone efficiency improvements and rely solely on expensive low-carbon fuels later may ultimately face significantly higher compliance costs.
Selecting the right combination of operational improvements and retrofit technologies can be complex.
This is where classification societies such as DNV play an increasingly important role.
Independent verification allows claimed fuel savings to become credible, bankable evidence that supports financing and investment decisions.
DNV publishes recommended practices covering hull performance, wind-assisted propulsion and air lubrication systems to ensure performance claims can be independently verified.
"The industry cannot build commercial financing models for energy-efficiency measures without transparent, independently assessed data," says Saenz de Santa Maria.
Artificial intelligence is also becoming a powerful tool for maritime optimisation.
AI enables continuous, fleet-wide operational decision-making based on real-time performance data at a speed and scale previously impossible.
However, she cautions that AI is only as effective as the quality of the data behind it.
Without consistent, transparent and validated data, AI risks adding complexity rather than improving operational performance.
Classification societies therefore have an important role in ensuring AI-generated insights can be trusted for both investment and regulatory compliance.
As AI capabilities continue to advance rapidly, industry standards must evolve just as quickly.
As Lead Partner of Nor-Shipping 2027, alongside DNB, DNV sees collaboration as essential to accelerating shipping's energy transition.
Saenz de Santa Maria believes the event provides one of the industry's most valuable forums for bringing together shipowners, operators, charterers, technology providers, financiers and policymakers.
Many of the challenges surrounding energy efficiency extend well beyond technology.
They include investment decisions, commercial contracts, fuel savings allocation between owners and charterers, and agreeing on independently verified operational performance.
"Nor-Shipping brings the entire maritime value chain together to have these conversations," she says.
With the 2027 event centred on the theme NEXT, she believes the industry's next move should be clear.
Energy efficiency is no longer simply a compliance requirement—it is the most practical, scalable and commercially attractive pathway available today for reducing emissions while preparing shipping for the low-carbon fuels and technologies of tomorrow.
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