A cruise ship has acres of open deck space and spends much of its life sailing under the sun. So why aren’t those huge ships covered in solar panels instead of burning fuel?
The problem isn’t a lack of interest in cleaner cruising. It’s that powering a floating city from sunlight is much harder than it sounds, although some ambitious new ships are getting surprisingly close.
The Current State of Cruise Ship Emissions
There’s a good reason cruise lines are looking for alternatives to traditional marine fuels. International shipping remains a significant source of greenhouse gas emissions, and pressure to cut those emissions is growing.
The International Maritime Organization (IMO) has set a target to reduce the carbon intensity of international shipping by at least 40% by 2030 compared with 2008. It also wants total annual greenhouse gas emissions cut by at least 20% by 2030, with an ambition to reach net zero by or around 2050.
Meeting those targets will require much cleaner ways of powering ships. Solar is one possibility, but there are some major reasons why it can’t simply replace conventional fuel on a modern cruise ship.
Why Solar Power Is So Difficult For Cruise Ships
There are several major obstacles to powering a cruise ship entirely with solar energy.
1. Cruise Ships Need Huge Amounts Of Power
Cruise ships are essentially floating cities, with enormous energy demands. Propulsion uses a huge amount of power, but electricity is also needed around the clock for air conditioning, lighting, kitchens, lifts, water systems and entertainment.
Large cruise ships can have power plants capable of generating tens of megawatts of electricity, with some of the biggest exceeding 90 MW. Solar panels simply can’t generate anywhere near that amount of power from the space available on a ship.
2. There Isn’t Enough Space For Solar Panels
Cruise ships may be enormous, but most of their exposed upper decks are already being used. Pools, waterslides, sports courts, restaurants and sun decks all compete for the same space where solar panels would need to go.
Panels and their supporting equipment also add weight, so covering every available surface isn’t necessarily practical.
3. Solar Panels Still Can’t Generate Enough Energy
Modern solar panels have become much more efficient, but there’s a limit to how much electricity can be generated from the relatively small surface area available on a cruise ship.
And unlike a solar farm on land, a ship can’t simply add more panels when it needs more power. Cloud cover, the angle of the sun and the ship’s location can also affect how much electricity the panels produce.
That’s why solar currently makes much more sense as a supplementary source of energy rather than the sole power source for a large cruise ship.
Innovations in Sustainable Cruising
Solar power might not be able to run a cruise ship on its own, but it could form part of the solution. Cruise lines are already experimenting with batteries, hydrogen, wind power and solar panels to reduce their reliance on conventional fuels.
Hybrid And Battery-Powered Ships
Battery technology is already being used at sea. In 2019, Hurtigruten’s MS Roald Amundsen became the world’s first hybrid-powered cruise ship, using large battery packs alongside its engines.
It’s not a fully electric ship, but it demonstrated how batteries could reduce fuel use and emissions rather than having to provide every bit of power themselves.
Hydrogen-Powered Cruise Ships
Hydrogen is another technology that’s moving much closer to reality. Viking Libra, described by Viking as the world’s first hydrogen-powered cruise ship, was floated out in March 2026 and is due to be delivered in November 2026.
The ship will use a hydrogen propulsion system capable of producing up to six megawatts of power, allowing it to operate with zero emissions for periods of time.
Viking Libra won’t be a one-off either. Viking Astrea, the cruise line’s second hydrogen-powered ship, was floated out in September 2026 and is due to enter service in May 2027. She’ll use a similar hydrogen and fuel-cell system, showing that Viking is already planning to use the technology across multiple ships.
Hurtigruten’s Sea Zero Project
One of the most interesting projects for the future of solar power at sea is Hurtigruten’s Sea Zero.
Hurtigruten’s Sea Zero project combines huge batteries with wind-assisted propulsion, solar panels and a much more energy-efficient ship design.
The research and development phase was completed in spring 2026, with Hurtigruten concluding that a ship could operate its Bergen to Kirkenes route without direct emissions during normal service.
The latest design uses a planned 73 MWh battery system as its main source of energy, charged with electricity from shore. Two retractable sails would help propel the ship and could be covered with more than 1,500 square metres of solar panels to generate additional electricity.
It’s a good example of where solar power may actually fit into the future of cruising. Rather than powering an entire ship by itself, it can work alongside batteries, wind power and more efficient ship designs to reduce the amount of energy needed in the first place.
The final research found that the combination of these technologies could reduce the ship’s overall energy consumption by around 44%.
Advancements In Solar Panel Efficiency
Solar panels are becoming more efficient, which could make them increasingly useful on ships where available space is limited.
Some experimental solar cells have already achieved efficiencies of more than 40% under laboratory conditions, while researchers are continuing to develop technologies such as tandem solar cells that can capture more energy from the same amount of sunlight.
Even major improvements won’t necessarily make a huge cruise ship capable of running entirely on sunshine, but they could make solar much more useful as one part of its energy supply.
Solar Power Is Likely To Be Part Of A Bigger Solution
Rather than relying on one alternative to conventional fuel, future cruise ships are likely to combine several technologies.
Solar panels could work alongside large batteries, wind-assisted propulsion, hydrogen fuel cells and shore-based charging. This approach allows each technology to contribute where it works best, rather than expecting solar power alone to meet the enormous energy demands of a cruise ship.
Projects such as Sea Zero show how that could work in practice, with solar providing additional energy as part of a much wider system designed to reduce emissions.
Economic And Environmental Incentives
Cleaner technologies aren’t only about reducing emissions. Fuel is a major operating cost for cruise lines, so technologies that reduce the amount a ship needs to burn could potentially save money as well.
Solar power is unlikely to eliminate a cruise ship’s fuel costs by itself, but even supplementary energy generated on board could contribute to reducing its overall energy consumption.
There are environmental benefits too. As cruise lines work towards tougher emissions targets, technologies such as solar, batteries and wind-assisted propulsion could become increasingly valuable as part of the solution.
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Final Word
Fully solar-powered cruise ships still look a long way off. Even as solar panels become more efficient, there simply isn’t enough space on a ship to generate the huge amounts of energy needed to keep everything running.
But solar doesn’t have to power an entire ship to be useful. Projects such as Sea Zero show how it could work alongside batteries, wind power and other cleaner technologies to reduce fuel use and emissions.
So the cruise ship of the future may not run entirely on sunshine, but solar power could still have an important role to play.
