LNG, Methanol, Hydrogen: How Sustainable Are Modern Cruise Ships Really?

Cruise ships have the bad reputation of being CO2 belchers. In reality, however, a lot is happening in the industry — from LNG propulsion through methanol readiness to hydrogen fuel cells. What does this mean in practice?

Heavy fuel oil: the problem

Until a few years ago, classic cruise ships ran on heavy fuel oil (HFO) — a sulphur-rich residual product of petroleum refining. The consequences: high sulphur and nitrogen-oxide emissions, particulate matter, soot particles. The IMO regulation MARPOL 0.5% (the sulphur cap from 2020) improved this considerably, but did not solve it.

LNG (liquefied natural gas): the state of the art in 2026

Liquefied natural gas (LNG) is the current state of the art. Advantages over heavy fuel oil:

• 99% lower sulphur emissions
• 85% lower nitrogen oxides
• 20–25% less CO2
• Practically no particulate emissions

The downside: methane slip — unburned methane escaping from the combustion engine is more harmful to the climate than CO2. With modern four-stroke engines this is technically controlled.

LNG ships in practice in 2026:

• AIDAnova (2018) — the world's first LNG cruise ship
• AIDAcosma (2022)
• Costa Smeralda (2019), Costa Toscana (2021)
• Iona (P&O Cruises 2020), Arvia (P&O Cruises 2023)
• Carnival Mardi Gras, Carnival Celebration, Carnival Jubilee
• MSC World Europa (2022), MSC Euribia (2023)
• Sun Princess (2024)
• Icon of the Seas (2024)

Methanol: the next level

Green methanol (produced from renewable electricity) is regarded as the fuel of the future, because it can be CO2-neutral when burned (provided it is synthesised from renewable electricity). Advantages over LNG: no methane-slip problem, easier storage (liquid at room temperature).

Methanol-capable ships in 2026:

• Mein Schiff 7 (2024) — the first TUI Cruises ship prepared for methanol operation
• The Explora class from ship III onwards (Explora Journeys)

The sticking point: green methanol is still expensive in 2026 (3–5 times the price of LNG) and not available everywhere. Ships are prepared, but mostly still run on conventional fuel.

Hydrogen fuel cells: the pilot phase

Hydrogen in fuel cells is in theory the cleanest option (emissions = only water). But: storage is challenging (cryogenic or high-pressure), the energy density is low. In 2026, hydrogen fuel cells on cruise ships are used only as auxiliary power (electricity for hotel operations in port).

Pioneers: Le Commandant Charcot (Ponant 2021) has a hybrid drive of LNG plus an electric battery — the batteries buffer for emission-free travel in polar regions. Full hydrogen propulsion for the main engine is announced for 2028+.

Battery hybrid and shore power

Two important complementary technologies:

• Battery hybrid — on the Hurtigruten Roald Amundsen and Fridtjof Nansen, and Le Commandant Charcot. Batteries buffer electricity for emission-free port stays.
• Shore power — ships switch off their generators in port and draw electricity from the city grid. The AIDAsol was the world's first cruise ship with port shore power in 2017 (Hamburg). Today many ports are equipped — but by no means all ships use the connections.

A realistic assessment for 2026

• LNG is the industry breakthrough — all large ships built from 2020 onwards are LNG or LNG-prepared
• Methanol is coming, but the availability of green methanol is the bottleneck
• Full hydrogen propulsion is realistic from 2030+, not earlier
• Climate-neutral cruising will not come through a fuel switch alone — efficiency, route optimisation and batteries must be combined

Conclusion for environmentally conscious travellers

Anyone who values sustainable cruising in 2026 should choose:

• LNG flagships such as AIDAcosma, Costa Toscana, Sun Princess or Icon of the Seas
• Cruise lines with a hybrid concept (Hurtigruten, Ponant Le Commandant Charcot)
• Cruise lines with a certified climate-protection programme (the Hapag-Lloyd Cruises premium brand, Explora Journeys)
• Cruise lines that consistently use port shore power (AIDA Cruises has stated this)

A fully CO2-neutral cruise does not yet exist in 2026. But the difference between a 2010s heavy-fuel-oil ship and a 2024 LNG ship is significant — a factor of 4–5 less pollutant emission.