Sea change: Testing maritime uses for alternative energy

Hydrogen, wind and solar on deck on Energy Observer’s around-the-world cruise

The Energy Observer visited San Francisco as part of its seven-year, around-the-world cruise. (Photo: Copyright Energy Observer Productions George Conty)

A small, unusual-looking vessel docked in San Francisco last week. It was the Energy Observer’s latest stop on a seven-year, around-the-world cruise to test and publicize the role alternative energy could play in the shipping industry.

The 100-foot-long catamaran, a converted racing boat, carries only five passengers and no cargo. At first blush it might seem irrelevant to the container industry or other segments of the marine cargo industry.

Yet Energy Observer (the ship and its operating organization have the same name) has attracted support from the world’s third largest  container shipping company, France’s CMA CGM. It has already visited Long Beach and San Francisco and departed last week for Hawaii.

CMA CGM has been pioneering the use of liquefied natural gas (LNG) as an alternative way to meet the low-sulfur fuel regulation of the International Maritime Organization (IMO) that went into effect last year. 


IMO member states also have pledged to cut greenhouse gas (GHG) emissions from international shipping by at least half by 2050 compared with 2008.

CMA CGM has said it aims to be carbon neutral by 2050. Recently it announced plans to support production of 12,000 metric tons of biomethane. CMA CGM said that amount of fuel could power two 1,400 twenty-foot equivalent unit (TEU) LNG-powered ships operating on its string between St. Petersburg, Russia, and Rotterdam, Netherlands, for a year.

However, CMA CGM operates a fleet of more than 500 vessels with combined capacity of 3 million TEUs, and some individual ships have capacity for more than 20,000 TEUs and ply long routes. It and other shipping companies realize in order to reduce carbon emissions, alternative means of propulsion, perhaps like those being demonstrated on the Energy Observer, will be needed.

Showcasing renewable energies

Heather Wood, director of sustainability at CMA CGM in the United States, said while the company is acting today with LNG vessels, “we recognize that the future is probably going to require a portfolio of options across the maritime industry. That is where Energy Observer is a player and why we have invested so much in that R&D and look at alternative forms of power” like hydrogen, solar and wind as marine fuels. All three are in use on the Energy Observer.


She and Energy Observer said there are preliminary discussions about building a second ship that would look more like a small freighter.

According to the classification society DNV, a joint industry project found “beyond 2035-2040, with today’s technologies, alternative low-carbon fuels will be needed to meet IMO carbon-intensity reduction ambitions.”

Katia Nicolet, a marine biologist on the Energy Observer, demonstrates the energy management system. (Photo: Chris Dupin)

Katia Nicolet, a scientist on board the Energy Observer, said the ship is attempting to showcase currently available renewable energies that can withstand the harsh environment at sea, including salt spray, extreme temperature, rough seas and lightning.

Nearly the entire upper surface of the ship is covered with 202 square meters of solar cells that generate electricity to charge batteries or manufacture hydrogen through the electrolysis of seawater. The hydrogen is stored in eight tanks below deck.

At night or at other times when sunlight is weak or wind is not available, that hydrogen can be turned into electricity with a fuel cell and used to power the ship’s electric motor and propellers as well as provide power to the Energy Observer navigation system and for the needs of its crew.

The batteries on the ship can generate about 120 kilowatt-hours (kWh) of electricity each day and can store about 100 kWh. The U.S. Energy Information Administration says the average American home uses 29 kWh per day.

The eight tanks on the ship can store hydrogen equivalent to about 2,000 kWh of power — half for propulsion and half to support the crew. 

Traveling clean, not fast

The Energy Observer also sports two OceanWings, inspired by the rigid sails used on the America’s Cup race boats. Nicolet said the OceanWings are twice as efficient as regular sails and do not create much shade on the solar panels.


Unlike the sails on the America’s Cup boats, however, those on the Energy Observer can be reefed to reduce their sail area or furled entirely in unfavorable winds. Energy Observer is also investigating the possible use of flexible solar panels on the wings.

While the ship travels 10-15 knots with good wind, it averages only about 5 knots, whereas big cargo ships sail at up to 20 knots.

“The goal is not to go fast but travel without emissions,” noted Nicolet.

The total weight of Energy Observer is just 30 tons. For perspective, that is about the maximum gross weight of a loaded 40-foot shipping container.

A big advantage to hydrogen is it’s lightweight. The hydrogen fuel on the ship weighs just 65 kilograms.

On the Energy Observer, the solar cells weigh about 2 tons, the two Ocean Wings 1.6 tons and the entire hydrogen production line 2 tons, including the desalination equipment, electrolyzer, fuel cells and storage tanks. The batteries on the Energy Observer also weigh about 1.5 tons, and Nicolet said if the ship stored all its energy in batteries, they would weigh 14 tons: “We would sink.”

Nearly every surface of the Energy Observer is covered by 202 square meters of solar panels that create electricity used to charge batteries and make hydrogen that is turned into electricity with a fuel cell to drive electric motors. (Photo: Chris Dupin)

Lighter than air

Victorien Erussard, the captain and founder of Energy Observer, noted hydrogen is much lighter than air and would take up a great deal of volume if not compressed. A two-stage compressor on board the ship allows hydrogen to be stored at 350 times atmospheric pressure at sea level (350 bars). That is about half the pressure at which hydrogen fuel is stored in Toyota’s Mirai automobile. Erussard said storing at 700 bars would allow the ship to carry twice as much fuel but would also require more energy for compression.

He added that when the Energy Observer transited the Panama Canal, it was “interesting to see our ship next to the big commercial ships. It is obvious that the energy system of our ship is not adapted to large ships that need a lot of power and huge quantities of energy so we have to put aside gaseous hydrogen, even at 700 bars, in favor of other forms of energy storage such as liquid hydrogen or ammonia.

“We work in a brutal and corrosive environment,” said Erussard. “I sleep close to the energy tanks and I feel very safe. The technologies we have developed on board are very safe and efficient.” 

(A nearly two-hour briefing on the Energy Observer given to the California Fuel Cell Partnership can be viewed here.)

Nicolet noted that while crew members must stand watch 24 hours a day, the sails, navigation and operation of the ship are highly automated — a necessity given its small crew. An energy-management system gives a centralized, real-time view of the complex systems on board.

As it travels to Hawaii, China and Japan, the ship will only have a crew of four. Over the next couple of years, the ship will travel to Southeast Asia, South Africa, Brazil and then the U.S. East Coast. Since being launched in 2017, the Energy Observer has visited ports throughout Northern Europe, the Mediterranean, the Caribbean and the Galapagos Islands. That provided an opportunity to test the performance of its systems in a variety of climates — from blistering heat off the coasts of Israel and Tunisia to the chilly waters of the Arctic Ocean on a visit to Spitsbergen, Norway.

Solar cells where the crew must walk have a plastic coating to prevent damage and reduce slipperiness. Solar cells over the water are “bifacial” so that reflected light also can be converted into electricity. Nicolet said this results in about a 25% boost in power generated by those cells.

Heat and fresh water — byproducts of electrolysis — are used by the crew for heat, drinking water, washing and cleaning. Nicolet noted that every few days the solar panels are washed to prevent salt from building up on their surface and harming their performance.

She said about 40% of the ship’s power comes from sails, 40% from solar panels and 20% from hydrogen fuel.

About 1% is created when strong wind allows the ship to stop using its electric motor for propulsion and instead use the turning propeller as an electrical generator as it is dragged through the water. It’s analogous to the electricity created by regenerative braking in a hybrid or electric automobile that is shunted to batteries.

Touting LNG

While most companies have opted solely for the use of very low-sulfur fuel oil or installing scrubbers to remove sulfur and particulates from ship exhaust, CMA CGM has aggressively expanded its use of LNG as a fuel using owned or chartered ships. U.S.-flag carriers such as TOTE and Crowley have also built LNG-powered ships, and many others here and around the world including the U.S. carrier Matson have built or are building dual-fuel ships that can be adapted to run on either liquid petroleum fuel or LNG.

In November 2017, Rodolphe Saadé, chairman and CEO of the CMA CGM Group, announced the carrier had ordered nine 23,000-TEU vessels powered by LNG. The first of those behemoths, the CMA CGM Jacques Saadé, was named for his father, the founder of the company, and launched last September.

By 2022, 32 of CMA CGM’s vessels will be LNG-powered. Six of those 15,000-TEU vessels will be deployed on CMA CGM’s Pearl River Express service, which sails from China to the Port of Los Angeles, with the first being deployed later this year. And on April 30 CMA CGM announced an order from China State Shipbuilding Corp. that will boost the number of the company’s LNG-fueled ships to at least 44 by the end of 2024.

Peter Keller, the chairman of SEA/LNG, a trade organization that promotes the use of natural gas as bunker fuel for ships, said LNG is “the only alternative fuel that’s available right now that takes care of all of the air-quality issues that we still have and reduces greenhouse gas emissions.”

Companies have embraced LNG to power ship engines in order to eliminate pollutants such as sulfur oxides, nitrogen oxides and particulate matter. 

But the knock against LNG is that it still produces carbon dioxide, albeit at lower levels than other fossil fuels. Production, transport and use of natural gas also result in the leakage or “slip” of methane into the atmosphere. Methane is a greenhouse gas with a global warming potential 28-36 times higher than that of carbon dioxide, according to the Environmental Protection Agency.

A World Bank report on LNG in shipping concluded that “despite its inherent air-quality benefits relative to oil-derived bunker fuels, LNG is unlikely to play a significant role in decarbonizing maritime transport” and “is likely to be used in niche applications like on preexisting routes or in specific vessel types only.”

The World Bank said not only are greenhouse gas “mitigation benefits uncertain, there are also considerable risks if countries and businesses invest in LNG infrastructure to meet the IMO’s climate targets, including unnecessary capital expenditures, stranded assets and technology lock-in.”

However, Keller said an updated “well-to-wake” study by consulting company Sphera shows “LNG plays an important role in decarbonization today with benefits available now” and called for similar studies on other alternative fuels to enable shipowners “to make the right decisions for their fleet.”

Said SEA/LNG, “While methane slip is an issue that needs to be addressed, its effect must be quantified using up-to-date and accurate information.”

SEA/LNG says current engine information “shows that methane slip does not impact LNG’s GHG reduction potential to the extent that the World Bank report claims.”

Keller said LNG is competitively priced and that infrastructure growth to support use of the fuel has been very satisfactory.

More than 120 ports provide LNG bunkers and Keller said, “We now see probably more than 50 LNG-capable bunkering vessels around the globe by probably sometime next year.”

According to figures published on the SEA LNG website, there are 198 ships in operation powered by LNG and 271 more on order; 146 ships are in operation or on order that have engines that are “LNG-ready,” meaning their engines can use either low-sulfur fuel oil or LNG.

Keller estimated 20%-30% of all newbuilds “now appear to have LNG capabilities.”

“Congratulations to CMA CGM — they are using LNG and then experimenting and testing longer-term alternatives,” Keller said. 

Onshore applications in trucking and logistics

Kitack Lim, the secretary of the IMO, said that a study last year found under all projected scenarios, “a large share of the total amount of CO2 reduction will have to come from the use of low-carbon alternative fuels.”

Very little hydrogen is being used as transportation fuel today at sea or on land. An article by BloombergNEF said at the start of 2020 there were only 17,000 passenger vehicles, 4,250 buses and 1,000 commercial vehicles using hydrogen fuel cells as power sources.

CMA CGM’s Wood said the technologies being tested on the Energy Observer also have onshore applications in trucking and logistics. 

Major manufacturers of Class 8 heavy-duty drayage trucks are exploring battery electric and hydrogen-fueled trucks. Wood said CMA CGM’s sister company, CEVA Logistics, also is exploring alternative fuels.

In Alameda, California, across San Francisco Bay from where the Energy Observer was docked, is Zero Emission Industries (ZEI), formerly Golden Gate Zero Emission Marine. The Sea Change, a ferry it has designed to run on hydrogen, is nearing completion at All American Marine in Bellingham, Washington, and is expected to begin sea trials this summer. ZEI says it is the first commercial hydrogen fuel cell vessel in the United States.

The hydrogen-fueled ferry Sea Change is expected to enter service later this year. (Photo: Zero Emissions Industries)

The owner of the ferry, SWITCH Maritime LLC, says it will operate in San Francisco Bay and will carry 75 passengers.

While the Energy Observer uses a Toyota fuel cell, the same one used in the hydrogen-powered Mirai, the Sea Change uses one supplied by Hydrogenics, now owned by Cummins Inc. (NYSE: CMI).

“We are not a boat company, we do not make ships; we make hydrogen technology that goes into them,” said ZEI CEO Joe Pratt.

Pratt was formerly a principal member of the technical staff at Sandia National Labs in Livermore, California, where he looked at multiple use cases in the large shipping fleet.

“There’s really no technical roadblocks to making that happen,” he said. “The fuel cell systems can scale up and down just like battery systems can. But they hold energy a lot denser so you can actually power a large ship with hydrogen fuel cells, whereas if you tried to do it with batteries you would basically be carrying around as many batteries as the boat itself.”

Climate-friendly shipping fuels

Hydrogen can be used in internal combustion engines, but a 2019 article in the journal Energy and Environmental Science said this is “less efficient than a fuel cell and releases NOx, hence is not expected to play a significant long-term role in transport.” In contrast, when hydrogen is converted into electricity with a fuel cell, the only exhaust is water and oxygen.

That article said marine freight accounts for about 12% of global energy use and predicted while marine applications are promising, “hydrogen is not expected to gain traction until after 2030, although the growth of emissions-controlled zones (such as the Baltic Sea and urban ports) and hydrogen’s higher efficiency than LNG could drive early niches.” 

It added that “most vessels have long lifetimes [and] are built in small numbers highly tailored to specific applications; this could hamper the rollout of new propulsion systems.”

The Environmental Defense Fund said, “Hydrogen and ammonia are the most climate-friendly shipping fuels because of their carbon-free ‘life cycle.’ They are produced using only water, renewable energy and air and do not emit any carbon dioxide when used. Ammonia and methanol can be used in existing ship engines with minimal adaptation.”

A report last month from the Washington-based Center for Strategic and International Studies (CSIS) said the nearly 1 billion tons of CO2 emitted by the shipping industry annually accounts for approximately a quarter of all emissions from the global transportation sector.

In its report, CSIS noted hydrogen fuel can be produced in three ways: 95% of the 70 million tons produced annually is “gray hydrogen,” made by combining fossil fuels (mostly methane) with water; smaller amounts of “blue hydrogen” are made at plants retrofitted with carbon capture, utilization and storage technology; and “green hydrogen,” like that produced on the Energy Observer, is made through electrolysis with renewable energy sources. Only about 5% of global hydrogen production is “green,” according to CSIS.

William Alan Reinsch, senior adviser and Scholl chair in international business at CSIS, said hydrogen may become the fuel of choice or at least a greater part of the mix because the industry is under great pressure to reduce emissions and get away from fossil fuels, and solar is not practical for ocean voyages.

How quickly hydrogen is adopted as a maritime fuel “probably depends on government policy,” he said. “The technology I gather is there now — it’s not like we are talking about fusion.”

CSIS said, “While gray hydrogen is currently reasonably price competitive with traditional fuel sources, costing around $1-2/kg H2, it fails to offer a sustainable solution to reduce GHG emissions at scale. Blue hydrogen is 30-80% more expensive than gray hydrogen, and green hydrogen is about four times costlier than gray hydrogen.” 

But the report added that “a 2020 study commissioned by the International Council on Clean Transportation determined that the cost of producing green hydrogen from renewable electricity in the United States and Europe could be halved by 2050 with financial incentives to promote R&D.” 

Skeptics about what role hydrogen will play in the future abound, perhaps most famously Elon Musk.

The Energy Observer is a platform for demonstrating the use of alternative energy on ships. (Photo: Chris Dupin)

But even IDTechEx, which wrote a report last year that forecasts cars powered by fuel cells “will continue to be a commercial failure for the next two decades,” said “they are not off the table yet in heavy-duty long-range applications such as off-road, marine and long-haul trucking.”

Using hydrogen to power ships on long transoceanic voyages would probably require it to be compressed and liquefied. But the U.S. Department of Energy noted that “using today’s technology, liquefaction consumes more than 30% of the energy content of the hydrogen and is expensive.”

Pratt, an optimist about the use of hydrogen as fuel, said studies at Sandia found that the hydrogen fuel cell power plant and tanks needed by a large oceangoing vessel using liquid hydrogen could fit within the same envelope that the fuel and an engine occupy today in an oceangoing ship that uses conventional fossil fuels.

“Essentially the ship is going to look the same,” he said.

A major benefit to fuel cells, he said, is that they require less maintenance than existing engines, though IDTechEx contended that in automobiles they can have higher maintenance costs than battery electric vehicles.

Pratt noted there have been sharp reductions in the cost of renewable energy over the past 20 years and that it continues to drop.

“It’s definitely conceivable that soon we will have hydrogen that’s actually cheaper than fossil fuels, in which case I don’t think there is any argument for continuing the fossil fuels even if they are still available,” Pratt said.

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