Norway takes gamble on hydrogen fuel
Charlie Bartlett, correspondent | 10 July 2018
Norwegian ferry operator Boreal Sjø and Wärtsilä Ship Design have entered into a cooperation agreement to develop a hydrogen-powered ferry to the Hjelmeland-Skipavik-Nesvik route in Norway
At 22 Karl Johans Gate, Oslo, an uncharacteristic gamble is taking place. In May, Norway’s government introduced legislation to ban any kind of carbon emissions in the waters of UNESCO World Heritage-protected sites Nærøyfjord and Geirangerfjord from 2026.
The biggest problem with this legislation is that the technology to achieve it does not exist. The Fjords, the joint-venture ferry company operating here, has just launched an all-electric, battery-powered, carbon-fibre-constructed ferry, Future of the Fjords. But thanks to the feeble local grid infrastructure, it can only charge enough to run one trip a day. Without major upgrades to the local power supply, even small vessels like this will struggle.
But the ban will also cover the huge cruise vessels that bring in revenues to the fjords every year. Batteries are unworkable for these heavyweights; with this kind of hotel load, even shore power is off the table. Options are limited to some form of nuclear reactor, methanol, or Norway’s darling of the moment, hydrogen.
Thought to be the future for the automotive industry before the arrival of practical battery-electric cars, hydrogen is also used as rocket fuel, and, in the past, for buoyancy on various airships.
It is far from the most practicable fuel, but it does offer some exciting possibilities. In theory, if bunkered on ships, it would emit nothing more than harmless water vapour. Vessels today running on four-stroke diesel engines could instead use fuel cells. This would almost double the efficiency, with fuel cells able to achieve 60% efficiency compared to around 30-35% for diesel engines. While also generating no NOx and little noise or vibration, this would be another boon for the fjords.
The future of fuel
There is a chance hydrogen may be poised for a take-off. Because renewable energy infrastructure such as wind turbines and solar fluctuate, the power cannot be used by the grid all the time. Various countries - notably Belgium - are examining using this spare energy to generate hydrogen through electrolysis (passing an electronic current through a solution containing ions to create a chemical reaction). As well as making better use of renewables, this could also increase hydrogen supply.
Unfortunately, today, these projects are small, and theoretical. Virtually all hydrogen is, like methanol, refined from non-renewable natural gas. Viewed holistically in a ‘well-to-tank’ (WTT) sense, non-renewable hydrogen adds carbon. According to DNV GL data, ‘steam-reformed’ hydrogen beats LNG in WTT CO2 emissions by around a third.
Even so, the Norwegians have elected to make the iron hot by striking, and are forging ahead. In collaboration with the Road Administration, The Fjords is tendering for design and construction of a new hydrogen-powered car ferry, CEO Rolf Sandvik told SAS.
“The Road Administration director went public saying the ferry will most likely be liquefied hydrogen," he said. “There is a lot of work to do on this, but it is possible, and they will award the first contract by the end of this year if the price is not prohibitive.”
Sandvik’s gamble is that a short-term CO2 increase - as these vessels begin their lives burning non-renewable-hydrogen - will be offset later by an increase in production of clean hydrogen.
However, one of the main difficulties with hydrogen is how it will be contained. Because of its low density it requires very large tanks. To put this into perspective, the US space shuttle’s eye-catching orange external tank (ET) contains only one seventh as much liquid hydrogen as liquid oxygen. Yet, the former requires three times as much storage volume as the latter.
According to DNV GL’s Alternative Fuels report, compressed hydrogen requires 15 times the storage volume of heavy fuel oil. Alternatively, in liquefied form, volume is five times greater. Another problem is temperature. LNG, which provides challenges for designers even today, requires storage at a balmy -162°C. Hydrogen, on the other hand, requires -253°C.
Asked how he expects to handle the gas on board, Sandvik responds: “It’s still not 100% clear. But there are a lot of hydrogen projects going on, both in compressed and liquefied forms.”
Combusting on contact with oxygen, hydrogen is potentially extremely dangerous if a tank springs a leak. In the event of a collision or grounding, results could be severe. For this reason, designs for hydrogen-fuelled vessels tend to locate tanks on top, where a blaze can vent away from the vessel, rather than in enclosed spaces within the hull. More must be done before hydrogen will be safe for use on vessels, Sandvik indicated: “For that project we and the other ferry operators are working together with DNV GL to develop the rules that need to be in place to operate a passenger vessel – and also a car ferry – on hydrogen."
Lars Langfeldt, senior project engineer at DNV GL - Maritime, is confident that hydrogen is a safe and practical option for these types of vessels. “Technologically, we know we can get there; on a regulatory basis, we know that if we do not have the basis, the technology can’t take off,” he told SAS. “What we do not want to do is wait until there is a reliable supply of renewable hydrogen and then begin rule development.
“The fuel industry must do their part, of course. They must supply the renewable hydrogen. The rule development we are doing will make it possible to use it.”
Langfeldt highlighted DNV GL’s involvement with Race for Water, a recent hydrogen project. 93kW of solar cells generate up to 200kg of hydrogen while in port, compressed and stored in tanks on board. Fed into two 30MWh fuel cells, this reserve of potential energy amounts to 2.6MWh, dwarfing the Race for Water’s 754kWh battery system.
Notably, the catamaran’s stored hydrogen reserve also outstrips Future of the Fjords’ larger 1.8MWh battery system. However, unlike Future, Race cannot accommodate 400 passengers, nor can it generate hydrogen and run the motors simultaneously. On top of this, it relies on 500 square metres of solar panels, the aforementioned battery system, and assistance from a skysail for propulsion – and even then, cannot move much faster than 5 knots. The case that hydrogen is a much better energy storage medium than batteries, therefore, is still a tricky one to make.
A possible solution to this – Ammonia (NH3), stored as a liquid at a far less finicky -33°C – is also under discussion at DNV GL. Sigurd Enge, shipping marine and arctic issues manager at Bellona (a consulting partner in the Future of the Fjords project) argued ammonia could be the only sensible way of using hydrogen as ship fuel, noting excitedly that it contains “more hydrogen than hydrogen”.
But Langfeldt has reservations. “The maritime industry has not really studied and tested how ammonia as a hydrogen carrier would behave in practice onboard vessels,” he explained. While he agreed that for bunkering and handling it could have some advantages for ships, namely that it can be stored as a liquid at ambient temperatures as opposed to dealing with the challenges of a -253°C cryogenic liquid.
“But the major question is – does it really have the efficiency we need?” said Langfeldt. “If you want to get the hydrogen out of ammonia, you must heat it up, to crack the hydrogen from the liquid. That thermic energy must come from somewhere.”
The new fjords regulation leaves only eight years to solve this problem, and during that time it is unlikely that a large, steady source of renewable hydrogen will come online. No wonder, then, that the Norwegians are forging ahead.