Energy efficiency is one of the most cost-effective and readily available ways to cut shipping emissions, easing the transition to green fuels. Improving energy efficiency has become not just a strategic advantage but a necessary step in meeting the sector’s 2050 net-zero goal.

Fuel-saving measures ease the transition

By reducing fuel use per voyage, improving energy efficiency lowers absolute fuel costs regardless of fuel type. This is particularly important since green fuels such as e-methanol and e-ammonia remain in limited supply and are three to five times more expensive than conventional fuels. As a result, the green premium becomes a smaller absolute barrier to adopting green fuels, both for individual shipowners and the sector as a whole.

Furthermore, energy efficiency helps buy time. According to DNV’s Maritime Forecast to 2050, energy efficiency alone could reduce fuel consumption by up to 16 percent. This is equivalent to removing emissions from 55,000 of the smallest ships or 2,500 of the largest. While it will not in itself ensure compliance with the forthcoming IMO fuel-intensity rules, energy efficiency can deliver a large part of the emission reductions needed for a zero-carbon future.

Supporting the uptake of energy efficiency measures

Despite the benefits and necessity of energy efficiency measures, a large part of the global fleet still needs to improve energy efficiency. Uptake of measures such as speed optimisation, weather routing and better port coordination remains low. The barriers are rarely technical, as most technologies exist and require no new infrastructure. Instead, the main obstacles are institutional, including split incentives, data uncertainty and misaligned business models.

Overcoming these barriers requires regulatory support, transparency and innovative financing. Verified data and standardised measurement build trust in performance claims. Third-party financing models, where an external party fronts the investment and is repaid through verified savings, realign incentives for shipowners and charterers. These solutions can help smaller actors overcome capital constraints and unlock efficiency gains at scale.

Denmark has taken a leading role in enabling this transition. As a strong advocate of global maritime regulation, Denmark successfully proposed the Energy Efficiency Design Index (EEDI), adopted by the IMO as a mandatory requirement for newbuild ships. Together with the Energy Efficiency Existing Ship Index (EEXI) and the Carbon Intensity Indicator (CII), these tools are helping to embed energy performance into the DNA of fleet operations.