by Sarah Kuta
Last updated: 10:40 AM ET, Thu September 17, 2026
Cruise lines are continuing to expand their use of environmental technologies, from multi-fuel engines and shoreside electricity to advanced wastewater treatment systems, according to a new report from Cruise Lines International Association (CLIA).
The annual Environmental Technologies and Practices report, published since 2018, tracks year-over-year adoption of environmental technologies and practices across more than 90% of global oceangoing cruise capacity. This year’s report covers 297 CLIA-member ships that operated during 2025, representing 98% of the association’s global capacity.
“Year after year, the data show cruise lines continuing to invest in the technologies, fuels, and operational capabilities that are making the global cruise fleet more efficient and positioning it for the future,” says Bud Darr, president and chief executive officer of CLIA.
One area that has seen significant growth is multi-fuel engine technology, which allows ships to switch between conventional fuels and zero- or near-zero-emissions fuels as those options become available.
The number of CLIA-member ships with multi-fuel engines has grown from one in 2018 to 30 today. Based on the current orderbook, 56 such ships are expected to be in service by the end of 2030, with 69 projected by 2039.
Cruise lines are also using less heavy fuel oil (HFO). Data reported to the International Maritime Organization show that HFO accounted for 60.6% of reported cruise-ship fuel use in 2024, down from 74.2% in 2019. Meanwhile, the combined use of non-HFO fuels—including marine diesel and gas oil, very-low and ultra-low sulfur fuel oil, LNG and other reported fuel types—increased from 25.8% to 39.4% over the same period.
CLIA's own tracking found that non-HFO fuels accounted for 40.3% of member cruise lines' reported fuel use in 2025.
Shore power has also expanded across the fleet. The number of CLIA-member ships capable of connecting to shoreside electricity has more than tripled since 2018, rising from 55 ships to 193 today. Those ships represent 65% of reporting ships and 72.5% of reporting capacity.
Another 47 ships are planned to receive shore power retrofits, while 39 new ships are scheduled to enter service with the technology. If those plans proceed, CLIA projects that 279 member ships will have shore power capability by 2039.
The technology allows ships to turn off their engines while docked and connect to the local electrical grid, where compatible infrastructure is available. CLIA notes that emissions reductions can vary depending on the local energy mix and other factors.
Port infrastructure remains a limiting factor: The association says just 40 cruise ports worldwide currently have at least one berth equipped with shore power.
The report also points to continued growth in emissions-control and water-treatment technologies. The number of member ships equipped with selective catalytic reduction systems, which reduce nitrogen oxide emissions, has increased from seven in 2018 to 96 in 2026.
Meanwhile, 293 reporting ships—nearly 99% of the fleet—can produce freshwater onboard. Of those, 218 ships can theoretically produce 100% of their freshwater needs without taking on water in port.
Advanced wastewater treatment systems are now installed on 249 ships, or nearly 84% of reporting ships. That's up from 136 ships in 2018. CLIA says all of its member cruise ships have onboard wastewater treatment systems and that its members have committed not to discharge untreated sewage during normal operations.
Waste-management technologies are also becoming more common. Microbial digesters, which process and reduce food waste, are now installed on 137 ships, up from 103 ships in 2022, when CLIA began tracking the metric. Seven ships currently use waste-to-energy gasification systems that convert waste into usable energy.
Darr says the industry's progress will depend not only on investments by cruise lines but also on the availability of new fuels and supporting infrastructure.
“Realizing the full potential of those investments will require fuel producers, governments, ports, energy providers, and other stakeholders to help create the conditions for safe, competitively priced renewable and lower-emissions fuels to be available at scale,” he says.
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