COLUMN | What kind of tugs should we be building? [Tug Times]

The Turkish-built all-electric tug Gisas Power (Photo: Corvus Energy)

As I write this, the world’s attention is turning towards the upcoming climate conference in Glasgow, which will probably have a lot to say about shipping. After all, most people never see a ship or meet a seafarer, and are content to believe that we are all polluting monsters so we deserve to be kicked around by well-meaning environmentalists. I suspect many world leaders will be happy to focus on shipping to avoid anyone looking at their own environmental misdeeds.

Meanwhile, the shipping industry has been doing a lot to improve environmental performance, as can be seen by studying any of the new tug designs that have been featured in our pages in recent weeks, but this will not satisfy the mob and we can expect further pressure to reduce our emissions. For a start, it now looks almost certain that shipping will accept that it must reach zero emissions by 2050, and the same is probably true of ports, so tugs will be under pressure to comply.

Added to this, a recent article by Ralf Garrn of Scope Group claimed that IMO requirements will demand that all ships of 400GRT or more must achieve a minimum Energy Efficiency Existing Ship (EEXI) rating, and will need an annual Carbon Intensity Indicator (CII) rating. Garrn, indeed.

For years we have been building tugs below 500GRT to avoid the more onerous international regulations, but many tugs are well above 400GRT and will be forced to comply. These indicators will initially be used to ensure we cut our carbon intensity by 50 per cent by 2050 (against an arbitrary 2008 baseline), but as I mentioned above, I believe this is about to change to 100 per cent by 2050. I imagine it will involve a lot more work as we all frantically start to measure our operational efficiency in terms of the grams of CO2 we emit per deadweight tonne per nautical mile, and seek ways to improve our numbers.

Most tugs last a very long time, so anyone building now or in the near future should be aiming to comply with the 2050 requirements. I see little point in building hybrid tugs because, although they might reduce emissions by 30 or 40 per cent, they will not go further than that without significant additional expenditure.

Of course we have the option of buying carbon credits or finding some other way to offset our emissions, but this is likely to be expensive and does not really solve the planet’s problems. I like to think that most people in the industry would rather find a zero-emission solution, even though we don’t have one at the moment unless, like Auckland, we have a port that is not too busy and can operate with battery-powered tugs and recharge them using green electricity. Sadly, for many of us, that is not an option.

So it seems that the first order of business is to find ways to fund and speed up research into clean fuels. In a recent report, shipbroker Gibson suggested this would almost certainly be in the form of a carbon levy. The people at Gibson claim “this could be enacted by implementing a levy on fuels for each tonne of CO2 emitted”, and they suggest the money could go into an IMO Climate Fund that would help close the price gap between zero carbon and conventional fuels and would help build a bunkering infrastructure to supply clean fuels such as hydrogen and ammonia.

However, Gibson cautioned that, “whilst this sounds plausible, the challenges are multiple. First, how to price the levy?…..Secondly, there is a very real concern that an additional levy on vessel fuel will ultimately have a knock-on effect on the end consumer….Thirdly, there is the problem with bunkering infrastructure. Which fuel will be available in which port? Will a port specialise in one fuel, or will it offer all future fuels? Finally, there is the economic uncertainty that will come with adopting alternative fuels.”

Gibson also pointed out that whatever is decided could take more than a decade to enact, and the clock is ticking. Had they been reading recent columns by my esteemed colleague Hieronymous Bosch, they could have added that, whenever large sums of money are involved, corruption is likely to rear its ugly head, and many carbon-offsetting schemes are not exactly kosher.

“Experts warn that unless there is sufficient production of zero-carbon, synthetic natural gas before 2050, it is unlikely that LNG can meet the zero-emission target.”

Certainly, the amounts of money involved are staggering. Dutch bank ING recently looked at China, Japan, and South Korea and calculated that their pledge to get their shipping to net-zero emissions by 2050 will cost them US$4.38 trillion.

That is not a typographical error. The figure really is US$4.38 trillion, and assumes all their ships will run on ammonia, which ING says “looks on paper to be the best bet, but it requires a lot of energy to make….. This could be expensive.”

In addition, ING pointed out that “China will need another 433 GW of renewable generation capacity at a capital cost of US$3.68 trillion to create green ammonia for its seaborne freight in the next 40 years.”

Many of these costs will undoubtedly be passed on to the consumer, so it will be interesting to see how much the general public are prepared to pay to remove the two per cent of global emissions that are attributed to shipping. Not a lot is my guess, and I wonder how many governments will fall when people see what environmental responsibility will cost.

On a brighter note, analysts seem to agree that these massive investments will generate a lot of new business and create a lot of new jobs, particularly for shipyards that specialise in building zero-emission vessels and anyone involved in renewable electricity generation.

So what is the poor tug owner to do? Well, some technologies are already with us. LNG-powered tugs are increasingly being considered, and there are currently more than 600 LNG-powered ships in operation or under construction (although I do not know how many of them are tugs). Sadly, experts warn that unless there is sufficient production of zero-carbon, synthetic natural gas before 2050, it is unlikely that the fuel can meet the zero-emission target.

We also have electric tugs, but they are currently relatively limited in terms of endurance. Many ports would have to increase the number of tugs in order to serve their customers electrically, but would their customers be prepared to pay the additional charges?

Then there are ammonia and hydrogen-fueled engines, which do not exist yet. Also experts warn that, although the cost of these new fuels will reduce over time, they expect them to remain significantly more expensive than the fuels we use today. Nuclear-powered tugs, anyone?

At this point I considered saying something silly about our tug engineers – “They are a fine bunch, but do we want them getting their hands on a nuclear reactor?” or something similarly rude. But it is a fact that most ports probably do not want nuclear-powered tugs within a thousand miles, so it is a non-starter, however clean nuclear power might be.

“It will be difficult for the shipping lines to keep using conventional tugs when a non-polluting option is available, even if it costs more.”

In addition, Mikal Boe of CORE-POWER thinks modern nuclear options such as molten salt reactors are best suited to very large ships. He points out that of roughly 100,000 ships on the water which are above 100 GRT, a mere 7,300 produce 47 per cent of marine emissions. These are the biggest bulkers, tankers, and cruise ships, so if they could eliminate their emissions, shipping would look much less polluting. He claims modern reactors could achieve this in complete safety, so let us hope the big ship people are listening.

One of the problems with trying to make sense of all this is that most studies are concerned with ocean-going vessels. The Getting To Zero Coalition recently commissioned a report titled Strategy for the Transition to Zero-Emission Shipping, which states that, “at this point in shipping’s transition, the most urgent commercial and policy actions are those that can contribute to increasing production and use of scalable zero emission fuels derived from hydrogen.” But this refers to ocean-going vessels, so I wondered if the same conclusion would be valid for tugs?

To answer the question, I decided to ask the lead author of the report, Dr. Tristan Smith, who is Reader at the Energy Institute, University College London. I thought an academic was less likely to be tainted either by commercial pressure or personal bias, and Dr. Smith is undoubtedly a leading expert on the subject. He replied to my questions with alacrity, and I am grateful to him for his help and frankness.

Starting with nuclear power, he was less confident than Mr. Boe, and argued that the costs and regulatory complications are significant. He agreed that it was a possible solution for the very largest vessels, although ironically, it might be easier to get permission to fit a nuclear device on a harbour tug because the owner would only need one administration to approve it. Ocean-going vessels would need worldwide approval, which might be problematic.

Dr. Smith seems much more relaxed about hydrogen and ammonia as fuels. When I pointed out that they are not available where I live, he responded that they are highly scalable and rapidly growing in availability because green hydrogen has been seeing growing demand in several sectors of industry, including fertiliser production. It turns out that China is a leader in the field. With Australia and Japan developing supply chains that will pass close to Hong Kong, it is not going to be difficult to obtain the stuff. He rightly points out that most tug owners do not need to wait for global availability of these fuels, so long as they can be obtained locally.

He is less keen when it comes to LNG, and says while the problem of methane slip has been substantially solved in the MEGi two-stroke engines, there are still problems in four-stroke engines, while fugitive methane is also an issue in the supply chain. He makes the interesting point that methane has been in the shadow of CO2 as a greenhouse gas for a long time, but is now emerging and gaining prominence. The pressures this creates will make LNG “either a lot more expensive or very difficult to justify politically, or both.”

Ressuringly, Dr. Smith seems to share my reservations about hybrid tugs, describing them as “a half-way solution that doesn’t make sense in the longer run unless you build to be hydrogen/ammonia capable/retrofittable or if you are building for 10 years life.”

Surprisingly, at least to me, he does not rule out the use of battery electric tugs, even in busy ports or where the local power stations still burn coal. He sees it as a question of capex versus opex over the lifetime of the tugs. Even if a busy port needed to build more electric tugs to allow for recharging time, and even if hydrogen/ammonia tugs are cheaper to build, he says the cost of bunkering hydrogen/ammonia will be “much higher,” and that may tip the scales in favour of the battery option. In addition, he does not worry about coal-fired power stations, because “the energy system will also need to decarbonise and the logic to build for the outcome of the transition rather than the current specification, is a strong one.”

This all seems eminently sensible to me, so I hope it helps you as you grapple with the specifications of your new tugs. No doubt many owners will decide to do nothing and continue as they are, but the clock is ticking on that option and the difficult decisions will have to be made sooner rather than later. There may even be an advantage if you become the first mover in your port or area – after all, it will be difficult for the shipping lines to keep using conventional tugs when a non-polluting option is available, even if it costs a few dollars more.

Alan Loynd

Alan Loynd is a master mariner with extensive seagoing and shore experience, especially in the areas of salvage and towage. He is the former General Manager of the renowned Hong Kong Salvage and Towage company. He now runs his own marine consultancy and was chairman of the International Tugmasters Association.