Shipping industry eyeing hydrogen fuel cells as possible pathway to emissions reduction; work by Germanischer Lloyd and DNV
07 September 2012
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| Germanischer Lloyd’s concept hydrogen-fuel cell container feeder vessel is fueled by liquid hydrogen. Source: GL. Click to enlarge. |
Although technical and operational efficiency improvements in conventional propulsion systems may lower CO2 emissions from ships by as much as 20% across the global fleet, such marked gains in efficiency will not stop the steady increase of total emissions from shipping or meet the ambitious reduction targets of the future. One possible pathway being explored by the shipping industry is the use of hydrogen fuel cells.
At a presentation at the GMEC (Global Maritime Environmental Congress) held earlier this month in Hamburg, Dr. Pierre Sames, Germanischer Lloyd’s Head of Research and Rule Development, examined the potential use of fuel cells in shipping, the use of renewable energy to produce hydrogen for use as fuel, the economics of the technology and looked at two concept designs for fuel-cell driven, hydrogen-fueled vessels.
Separately, DNV has released a position paper, “Fuel cells for ships”, exploring the potential for fuel cell technology in on-board marine applications and the current status of the technology. The paper also discusses certain safety aspects, and highlights the development of mathematical models for assessing performance and operational aspects of shipboard fuel cell systems via simulation.
The paper examines the Phase 1 results of the DNV-led project FellowSHIP (Fuel Cells for Low Emissions Ships, earlier post), the first large-scale fuel cell installation operating on board a merchant ship. The first phase of the FellowSHIP project wrapped in 2010; in 2011, DNV kicked off a continuation of the FellowSHIP project named HybridShip. HybridSHIP is concerned with introducing batteries for on-board energy storage, integrated with fuel cells and gas engines.
Germanischer Lloyd. In his presentation Dr Sames set out GL’s design concept for a zero-emission container feeder vessel (above). The concept design, which targets Northern European feeder services, uses liquid hydrogen as fuel to generate power with a combined fuel cell and battery system.
The design concept addresses typical feeder services with a full open-top 1,000 TEU intake and 160 reefer positions at a service speed of 15 knots. The vessel is powered by a fuel cell system which delivers up to 5 MW to two podded propulsors. A battery system provides peak power. Multiple type C tanks hold 920 m3of liquid hydrogen to facilitate a roundtrip equivalent to ten full operating days.
With strict limits on sulphur emissions set to come into effect in 2015 in the Baltic Sea, ferry owner and operator Scandlines turned to FutureShip, GL’s consulting subsidiary, to help them develop a fuel-cell-driven concept design with for their Baltic ferry lines.
This design is for a double-ended ferry for with space for 1,500 passengers and 2,200 lane-meters for vehicles. Located on deck, the hydrogen tanks can accommodate 140 m3—enough for a passage of 48 hours, Dr. Sames noted. The fuel cells offer a rated power of 8,300 kW and the storage batteries a capacity of 2,400 kWh. The nominal speed of the ferries is set at 17 knots—the parameter used for sizing the fuel cells. To accelerate up to 18 knots, the four 3 MW pod drives draw additional current from the batteries. Flettner rotors on deck add to the energy efficiency of the design.
For a true “zero”-emission vessel, it is necessary to go beyond the emissions from the ship itself and account for the production of its fuel as well. The GL design concept proposes using wind energy to produce LH2. A 500 MW wind farm could produce up to 10,000 tonnes of liquid hydrogen from surplus power it is unable to feed into the gird. GL estimates that liquid hydrogen produced by wind power could be commercially attractive between 2020 and 2030, provided that the price of MGO increases beyond US$2,000/t.
In 2020, current estimates are that approximately 3GW of offshore wind energy generation capacity will be installed in the German Exclusive Economic Zone alone. But up to 30% of the generated power may not be put into the grid and therefore could be available for hydrogen production (up to 3,600 GWh/a).
Two recently opened projected in Germany, Dr Sames pointed out, have demonstrated how using hydrogen to store surplus energy was already a viable technology. The two plants, at Prenzlau and Falkenhagen, have been in operation for the better part of a year and use wind energy to generate Hydrogen through electrolysis, which can be then stored and used to power vehicles (Prenzlau), or fed directly into the natural gas pipeline system (Falkenhagen).
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| Fuel cell system integration in the Viking Lady. Source: DNV. Click to enlarge. |
DNV FellowSHIP. In the FellowSHIP project, a 330 kW fuel cell was successfully installed on board the offshore supply vessel Viking Lady, and demonstrated smooth operation for more than 7,000 hours. When internal consumption was taken into account, the electric efficiency was estimated to be 44.5%, and no NOx, SOx and PM emissions were detectable. When heat recovery was enabled, the overall fuel efficiency was increased to 55%. Nevertheless, noted DNV Research and Innovation, there remains potential for further increasing these performance levels.
Although fuel cell technology is not new, and has been tested before on ships, the FellowSHIP project marked the first large-scale fuel cell installation operating on board a merchant ship. Viking Lady is also the first vessel to use high-temperature fuel cell technology.
The project used a molten carbonate fuel cell (MCFC), developed by MTU in Germany and modified for operation in a marine environment. LNG is the main fuel in the gas-electric propulsion system of Viking Lady; no additional fuel system to support the MCFC was needed. In the current installation, the MCFC delivers power to a direct current (DC) link that is connected to the ship’s alternating current (AC) bus through power converters. The ship’s electric propulsion system therefore consume fuel cell power equivalently to power provided by the main generators.
The fuel cell stack, together with the required balance of plant, is located in a large, purpose-built container (13 x 5 x 4.4 m). Project-specific electrical components (transformers, converters and DC bus) designed to protect the fuel cell from potentially harmful disturbances on the power grid, are situated in a standard 20-ft container. The total weight of the containers is 110 tons, but both weight and volume could be significantly reduced in future fully integrated systems, DNV noted.
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| Fuel cell integration in the propulsion system. Source: DNV. Click to enlarge. |
Viking Lady began operations on the North Sea in April 2009, and, in September of the same year, had the 330 kW MCFC power pack installed. After initial testing, Viking Lady became the first vessel to obtain the class notation FC-Safety. The FellowSHIP fuel cell installation is not classed as main or auxiliary power, but is considered as supplementary power.
During the first year in operation, the fuel cell stack showed no signs of degradation. In January 2012, the fuel cell was cooled down and conserved for future demonstration projects.
Fully loaded, the fuel cells produced electricity at a measured electric efficiency of 52.1 % based on the lower heating value of LNG.
DNV has paved the way for safe and smooth introduction of fuel cells for ships. We recognize that it will take time before fuel cells can become a realistic on-board alternative, mostly restricted by costs, but the FellowSHIP project has taken some important first steps towards a future for fuel cells on ships.
—DNV researcher Eirik Ovrum
Resources
52.1% efficiency based on the LHV is good. If e.g. a gas turbine could squeeze 25% efficiency out of the waste heat by running the system pressurized, the net would go up to 64%.
Posted by: Engineer-Poet | 07 September 2012 at 06:42 PM
I REALLY like the idea of using offshore wind turbines to produce stores of hydrogen from what is not used by the municipal grid. That's a remarkably good idea.
Posted by: EVryman | 07 September 2012 at 07:48 PM
If the carbon dioxide situation is that serious, we should bite the bullet and utilize nuclear power more. Not so much for ships, but for electric power generation. For ships, if we are to utilize any cryogenic liquid fuel, I would rather use liquified natural gas in combination with advanced gas turbine engines.
Posted by: Alex Kovnat | 07 September 2012 at 08:13 PM
When I was growing up there was a lot of talk about nuclear powered ships like the Savannah but not a lot came oue of it. This from wikipedia: "Nuclear powered, civil merchant ships have not developed beyond a few experimental ships. The US-built NS Savannah, completed in 1962, was primarily a demonstration of civil nuclear power and was too small and expensive to operate economically as a merchant ship. The design was too much of a compromise, being neither an efficient freighter nor a viable passenger liner. The German-built Otto Hahn, a cargo ship and research facility, sailed some 650,000 nautical miles (1,200,000 km) on 126 voyages over 10 years without any technical problems.[citation needed] However, it proved too expensive to operate and was converted to diesel. The Japanese Mutsu was dogged by technical and political problems. Its reactor had significant radiation leakage and fishermen protested against the vessel's operation. All of these three ships used low-enriched uranium.
Sevmorput, a Soviet and later Russian LASH carrier with icebreaking capability, has operated successfully on the Northern Sea Route since it was commissioned in 1988. As of 2012, it is the only nuclear-powered merchant ship in service."
OTOH there may be a future in going back to wind powered ships;
http://www.youtube.com/watch?v=qyLjISR6XQQ
http://www.treehugger.com/cars/cargo-ship-with-kites-first-trans-atlantic-trip-a-success.html
http://www.nytimes.com/2012/08/28/science/earth/cargo-ship-designers-turn-to-wind-to-cut-cost-and-emissions.html
http://www.sautercarbonoffsetdesign.com/emax-deliverance-dyna-wing-supertanker.html
Posted by: ai_vin | 07 September 2012 at 09:24 PM
How about methane and a SOFC to burn it directly?.. that way you can use the existing infrastructure.
Posted by: Herm | 07 September 2012 at 10:05 PM
I understand that the Savannah was only marginally uneconomical, and it would have been quite profitable had it been kept in operation through the 1973 oil price shock.
Posted by: Engineer-Poet | 08 September 2012 at 05:20 AM
This is non sense for this century, nat-gaz would be a better option and way cheaper and almost as clean and it would halves the CO2 emission
Posted by: Treehugger | 08 September 2012 at 08:38 AM
Not having to stop for fuel for the life of the ship, and being able to cruise at maximum speed regardless of the length of the journey, might offer advantages over LNG.
Posted by: Engineer-Poet | 08 September 2012 at 11:37 AM
Why not burn the LH2 directly in the huge diesel engines? These engines are capable of over 50% thermal efficiency, which is on par with FC. The engines already exist and only need some modification to adapt to LH2 or LNG. NOx is not a big problem in the middle of the ocean, and with LH2 or LNG, NOx emission would be a lot lower than with bunker fuel.
Posted by: Roger Pham | 08 September 2012 at 01:33 PM
Not having to stop for fuel for the life of the ship, and being able to cruise at maximum speed regardless of the length of the journey, might offer advantages over LNG.
These are great advantages to have - in a military ship. However in shipping there are operational realities that negate such advantages. There's no advantage to not stopping for fuel if you do have to stop for loading/unloading cargo. And maximum speed over any length of journey is dictated more by seakeeping and queueing at the port. A cargo ship will run at the most efficient speed that allows it to reach its destination at the desired time, and no faster. The desired time is set by shore based factors and not the ultimate speed capabilities of the ship.
Posted by: ai_vin | 08 September 2012 at 03:09 PM
If you can go faster you can get an earlier queue slot; arriving sooner means unloading sooner and making more runs per year. If fuel is effectively free and you can operate at continuous maximum speed without penalty, you can bypass bottlenecks like the Straits of Malacca and avoid other problems like risk of piracy (just keeping the speed way up makes boarding far more difficult, not to mention forcing pirates to operate much further from base).
Posted by: Engineer-Poet | 08 September 2012 at 08:35 PM
Good points.
Posted by: ai_vin | 09 September 2012 at 10:08 AM
I suppose the next question should be 'is the nuclear power really effectively free?'
We were promised that nuclear power would be effectively free ("too cheap to meter") before, but it isn't. What costs, other than the fuel, have hindered the use of more nuclear powered ship to date?
Posted by: ai_vin | 09 September 2012 at 10:19 AM
They should try to build and install a hydrogen water electrolyzer into that hydrogen ship instead of relying to a far away external wind farm based electrolyzers.
Posted by: A D | 09 September 2012 at 11:54 AM
ai_vin, the fuel is effectively free. The cost of the system is mostly in the physical plant; you pay almost the same whether you run it at 40% or 100%.
Posted by: Engineer-Poet | 09 September 2012 at 01:00 PM
Yeah, but if it were that simple there would be hundreds of nuclear power cargo ships traveling the trade routes now. Why aren't there? What are we missing from the equation?
Posted by: ai_vin | 09 September 2012 at 01:16 PM
A number of countries have exclusionary policies for nuclear vessels (New Zealand is/was one, IIRC).
There's also the stigma of "it was tried and didn't work" (NS Savannah), ignoring the little detail that the Savannah's economics would have worked great if it had only been kept in service until after the 1973 oil-price shock.
Posted by: Engineer-Poet | 09 September 2012 at 04:18 PM
The fact of the matter is all they are doing is checking to see how such systems work because in a fairly short timeframe the fuelcell will replace the diesel engine simply because its easier and cheaper to run.. likely timeframe still 20 years out but closing in.
Posted by: wintermane2000 | 09 September 2012 at 08:14 PM
Actually I don't think the Savannah's economics would have worked great if it had only been kept in service. But not because nuclear powered ships are a bad idea. The fact is she was never meant to be more than a showcase and demonstration project for the potential usage of nuclear energy. From wiki: Savannah was a demonstration of the technical feasibility of nuclear propulsion for merchant ships and was not expected to be commercially competitive. She was designed to be visually impressive, looking more like a luxury yacht than a bulk cargo vessel, and was equipped with thirty air-conditioned staterooms (each with an individual bathroom), a dining facility for 100 passengers, a lounge that could double as a movie theater, a veranda, a swimming pool and a library. Even her cargo handling equipment was designed to look good... Savannah's cargo space was limited to 8,500 tons of freight in 652,000 cubic feet (18,000 m³). Many of her competitors could accommodate several times as much. Her streamlined hull made loading the forward holds laborious, which became a significant disadvantage as ports became more and more automated. Her crew was a third larger than comparable oil-fired ships and received special training in addition to that required for conventional maritime licenses... As a result of her design handicaps, training requirements, and additional crew members, Savannah cost approximately US$2 million a year more in operating subsidies than a similarly sized Mariner-class ship with a conventional oil-fired steam plant. The Maritime Administration decommissioned her in 1971 to save costs, a decision that made sense when fuel oil cost US$20 per ton. In a note of historical parallel, the ship's namesake, the SS Savannah, which in 1819 became the first steam powered ship to cross the Atlantic Ocean, was also a commercial failure despite it being an innovation in marine propulsion technology.
The Savannah just isn't a good example of what a nuclear powered cargo ship COULD be.
Posted by: ai_vin | 09 September 2012 at 11:45 PM
Of course not, but the fact remains (IIRC) that it WOULD have been competitive DESPITE its handicaps after 1973. That says a lot.
Posted by: Engineer-Poet | 10 September 2012 at 08:22 PM
Speculation.
Posted by: ai_vin | 11 September 2012 at 09:58 AM
In case military standard reactor aplication for merchant ship the business could be profitable. One major requirement - reactor shall be sealed and maintanance free.
Posted by: Darius | 12 September 2012 at 03:38 AM
RE: Comments above on nuclear power and natural gas and methane:
The thing I liked most about this was the fact it offers a much smarter alternative to natural gas! Why would natural gas be preferential to their idea of wind energy-produced liquid hydrogen?! Same argument applies to other comment on methane. These simply don't resolve that CO2 factor they were trying to address on zero emissions. Also like the comments on the advantages of fewer fuel stops.
And RE: nuclear: I don't see what that has to do with this... If anything, we've just been reminded of the excess we already have in wind produced energy and we've been shown an intelligent way to ulitise this excess. Surely this serves to remind us of the huge untapped potential in clean renewable energy sources and thus, the lack of need for nuclear.
Posted by: Yasmin Quayyum | 13 September 2012 at 03:47 AM