The new Star of the Seas is about 24 percent more efficient than previous Oasis-class ships for Royal Caribbean International, said Nick Rose, associate vice president of environmental programs.

The main drivers are new streamlined hull design, the move to LNG as a fuel, and significant improvements made in waste heat recovery, even gaining ground from the Star’s sister, the Icon, which launched in 2024.

Since the ship is designed to run on a gaseous fuel, it is also using new tech to convert waste into energy, using Microwave-Assisted Pyrolysis and Micro Auto Gasification.

Of note is the company’s low port-mode energy system, that understands who is off the ship and may adjust staterooms lights and HVAC as needed.

“We’re using machine learning to see if someone is off the vessel,” said Rose.

LNG

New fuel is the real game changer, said Rose.

“LNG is just more energy rich on a per molecule, mass level,” he said. The one drawback is it requires more space.

Since it is cooled down to -260 degrees Fahrenheit, the Icon and Star are able to not only harness waste heat recovery, but use the energy off the cooling as well.

“It’s not just waste heat … we’ve always recovered on the heat side and now we can recover both,” Rose added.

Without much time between Icon sister ships, another newbuild is due from Meyer Turku in 2026 and Rose promised some tweaks.

“We are looking at some things for the Legend and other Icons … we need to build some things in to be more flexible in the future in case there is another kind of fuel,” he said, pointing to the Celebrity Xcel which will be methanol ready.

While any efficiency gains between sister ships delivered annually may be modest, the total gain between the first ship of the class and the last ship could be significant, Rose said.

AI

“We have partnered with good experts, the yard and third-party vendors to review data and plug into models,” said Rose.

“The yard has its model of the ship showing the most optimized hull, and then we feed them data back in real time,” he continued.

That data is then helping to optimize not only the current fleet, but future newbuilds.

“That includes our retrofit program” Rose continued. “We can now tap into more individual systems. We can see a pump that is running 24/7 and understand the data, and whether we need to continuously run that pump. AI can tell us when to have service it, replace it, or tell us that maybe it’s working too hard.”

This all falls under the company’s MIAP (machine learning and AI program).

“For the first few years, it was about collecting data,” said Rose.

With data collection set up, then it came time to teach an AI tool how to review it and make suggestions.

It comes down to energy, air and water, said Rose.

“It’s the totality of everything  we do. For example, the Star of the Seas is capable of producing 100 percent of its own water. We have an efficient reverse osmosis system and we are producing water at the most efficient rate, but also not consuming too much water.”