Over recent years, the hurdles standing in the way of a rapid expansion of the EV market have been overcome one by one. Declining battery costs have dovetailed with increasing public recognition of the need for deep decarbonisation. The performance of electric vehicles now frequently matches and exceeds that of conventional ICE vehicles, driving consumer interest in electric alternatives. By the year 2030, there will be over 125 million EVs on the roads, according to the IEA.

The maritime industry is watching closely. True, shipping faces many barriers that the EV market does not. Deep sea vessels undertake long voyages that keep them away from refuelling infrastructure for weeks at a time. Even the most advanced battery chemistries can’t match the energy density of fossil fuels, making batteries poor contenders as a primary power source for these types of vessels.

But fixating on large container vessels and all-electric solutions is missing the point. Marine battery propulsion isn’t a technology of the future – it’s here today. A surprising number of vessel categories have already proven to be ideal candidates for electrification, including passenger ferries, urban commuter vessels, OSV’s and tugs. Short journey times and predictable patterns of movement reduce any difficulties associated with charging infrastructure and battery depletion.

Even on much larger ships, batteries are demonstrating that they have a valuable role to play. Hybridised with conventional propulsion systems, they can bring down fuel costs, improve engine performance and reduce harmful emissions when maneuvering close to urban centres.

It is these niche and ancillary applications that will see the largest growth opportunities for marine batteries in the near future. Considered as a whole, they represent significant in-roads within a sector that has proven stubbornly difficult to decarbonise. These incremental gains will also help to prepare the way for the more deep-reaching decarbonisation measures needed to comply with the IMO’s pledge of a 70% reduction in maritime CO2 emissions by the year 2050.

With that in mind, KNect365 Energy attended the Electric and Hybrid Propulsion Seminar in London to find out more about the electrification of shipping. To get you up to speed, here are four observations about the key drivers, opportunities and trends shaping the sector.

It’s the emissions, stupid

Decarbonisation represents a huge challenge for the shipping industry. According to Lucy Gilliam of the non-governmental umbrella organisation Transport & Environment, shipping is now the largest sectoral emitter of CO2 within transport, accounting for an estimated 2.6% of all anthropogenic CO2 emissions.

But the industry has its sights firmly fixed on what is arguably a more pressing near-term objective. As of 2017, heavy fuel oil (HFO) accounted for 84% of the marine bunkering fuel mix. It is a major source of emissions of Sulphur Oxide (SOX), Nitrogen Oxide (NOX) and particulate matter (PM).

“SOX and NOX emissions are particularly harmful to human health – they’re implicated in cardiovascular disease and respiratory problems,” Gilliam says. Globally, these emissions are estimated to be responsible for 50,000 premature deaths every year.

Particulate pollution is also a huge problem. The 2018 State of Global Air report ranks ambient particulate matter as the sixth highest risk factor for early death worldwide. Sources of PM emissions are various and include coal power plants, industrial facilities and diesel automotive engines. Shipping is another prime culprit.

As a result of the IMO’s Sulphur 2020 regulations, which will limit the maximum sulphur content of bunkering fuel to 0.50% m/m, the shipping industry is currently scrambling to adopt alternative fuel sources. Low Sulphur Fuel Oil, Marine Gasoil, and LNG are all contenders. A small but significant percentage of the global fleet will also adopt scrubbers, a technology designed to remove SOX directly from exhaust gasses.

The maritime sector’s focus on the emissions most harmful to human health will also create genuine opportunities for electrification. A surprisingly high percentage of European shipping emissions come from vessel types which are already suitable for fully electrified alternatives. As much as “15% of the EU’s maritime emissions could be in this category of short sea shipping, ro/ro passenger vessels and et cetera,” says Gilliam.

Batteries can also help larger ships to limit harmful emissions when they move into ports or travel close to population centres. Installed alongside conventional propulsion systems, they can be used to handle short duration loads when needed, and recharge from the main motor once the vessel is safely out to sea.

The Norwegian model

Norway is without a doubt the world leader in marine battery propulsion. The country’s long, convoluted coastline and abundance of small coastal and island communities means that it has plenty of the ferries and passenger vessels most suitable for electrification. Mountainous terrain and heavy precipitation are another advantage, allowing the country to obtain 99% of its electricity cheaply from hydroelectric power facilities, and creating ample room for the electrification of other sectors.

These geographical factors have been supplemented by a willingness on the part of regional authorities to bear the cost burden of purchasing more expensive vessels and installing recharging infrastructure. “Norway has taken on the development cost,” says Hege Økland, CEO of NCE Maritime CleanTech. “The batteries are being commercialised at a much lower price.”

That has made it cheaper for other regions to start adopting the technology. It also sets a precedent for the workability of electric shipping projects. Panos Mitrou, from Lloyd’s Register, explains that Norway is often used as an example “to convince other people that these things are feasible.”

He points to Greece and the East Mediterranean as a region that is seeking to emulate Norway. Like its Scandinavian counterpart, Greece has impressive renewable energy potential. At present, half of the country’s annual power demand of 10 GW is generated from renewable sources. Renewables are expected to rise to 12 GW by the year 2025, placing the country in the enviable position of possessing a clean energy surplus.

The country also has innumerable small coastal and island communities, all of which rely on shipping for transportation and trade. More than 150 vessels operate on these routes, according to Lloyd’s Register. As Greece shifts to a surplus renewable energy grid, these kinds of journeys will become cheaper and cheaper to electrify.

Nevertheless, there are limitations to implementing the Norwegian model. “What’s special about Norway is that we… take one step ahead of many other countries when it comes to regulations and technological solutions,” Økland, says. “The drawback is that they might not fit into other markets.”

One example Mitrou provides of this kind of mismatch is the additional redundant battery capacity imposed by safety-conscious Norwegian ferry standards. These standards are being replicated all over the world, but the costs of purchasing extra battery capacity could slow the pace of electrification in less well supported markets.

Adapting marine electrification to different regions requires innovative approaches to cost saving. For instance, Greece is looking to solve the redundant capacity problem not by purchasing larger batteries than it needs, but by investing in aluminium-air batteries to provide a back-up power source. Aluminium-air batteries have some of the highest energy densities of any battery chemistry, but can only be discharged once, making them ideal for emergency situations.

Smoothing out the load

The EV market is the prime testing ground for electrifying transport. But there are also some lessons that the shipping industry can draw from the emerging role of battery storage in the power sector.

Utilities are only just beginning to get to grips with the various ways in which batteries can enhance grid performance. They are increasingly being used to provide a host of ancillary services like load following and frequency regulation that make the grid more efficient, more stable and more responsive. Adding additional battery storage capacity to the grid also prevents curtailment of excess renewable power supply at the times when the amount of electricity generated exceeds the level of demand.

Batteries can perform a similar function in promoting efficiency aboard vessels. “We have a new way of thinking about energy – and batteries enable this thinking,” says Sondre Henningsgård, Managing Director of the Marine Battery Forum. “Any fluctuating load we can now harvest and store for when we want to use it.”

When a ship travels through heavy seas, the demands placed upon the propulsion system vary considerably from moment to moment, not unlike the varying demands placed on the power grid throughout the day. Conventional engines are not able to react to these rapidly fluctuating force requirements: they exert a near constant level of torque, irrespective of the changing state of the ocean. The result is that the ship uses more fuel than it really needs to.

That’s where batteries can help out. Electric systems are able to respond to load variations in fractions of a second – and when they do, there’s no ‘power-up’ time. “Once you flick the switch, you basically have instant torque”, says Henningsgård. When the engine applies more force than is needed, the battery can use this to recharge. When it applies too little, the battery can deliver the extra power required.

How much fuel can be saved through the installation of a hybrid electric system depends on which system is used, the configuration of the engine, and the demands placed upon a vessel during a given voyage. To provide some idea of the range of efficiency savings, estimates for the “Wärtsilä HY” hybrid system are of a 10% – 20% reduction in annual fuel consumption.

Comparing battery chemistries

At present 80% of the batteries used within the shipping sector are NMC (Lithium Nickel Manganese Cobalt Oxide) varieties, according to Henningsgård, with Iron Phosphate chemistries making up the bulk of the remainder. But LTO (Lithium-titanate) batteries are “the new guy on the block, and the one to watch out for,” he says.

One early adopter of LTO batteries is Green City Ferries, who used them to develop the BB Green – the “world’s fastest electric commuter vessel”. Although LTO batteries are a more expensive upfront investment, the company’s Executive Director, Hans Thornell, believes that focusing on the price of a battery is misleading.

“The price of LPO is high, but the cost is low”, he says. LTO batteries suffer from very little long-term degradation compared to other battery chemistries, meaning that operational costs over the long-term are significantly reduced.

Nevertheless, there is a risk implied by these kinds of long-term cost assessments. As one sceptical attendee pointed out, the pace of technological development within the sector is such that the price of any given battery chemistry in five years’ time or more is very difficult to predict. If cost declines outpace the expected savings from choosing a more long-lived battery, betting on the short term may well prove the better option.

This kind of uncertainty mirrors a broader uncertainty about how the transition to low-carbon alternatives will play out, in the shipping sector and elsewhere. Picking a given technology before clear winners start to emerge is understandably daunting.

One thing is less uncertain though: whoever the winners may turn out to be, those who do nothing to prepare themselves for a low emissions future are sure to lose out.

If you'd like to hear more about electrification within the shipping industry, tune in to the GST & Shipping 2030 Digital Week, where Sondre Henningsgård will talk about reducing the costs of outfitting a fleet with electric propulsion.