Exploring the Role of Batteries in Decarbonizing Global Shipping

In the vast world of global trade, shipping plays a crucial role, moving 90% of goods across continents. However, this vital industry is also responsible for nearly 3% of global emissions, posing a significant environmental challenge. Despite international efforts to transition towards cleaner fuels, the shipping industry has faced setbacks, particularly from the United States. Yet, as battery prices continue to decline, there may be a viable path forward.

Electric ferries are already in operation, shuttling passengers and vehicles over short distances. Similarly, harbor tugs and inland cargo vessels are also embracing electrification. This trend works well for short routes where vessels can recharge at docks. But can this approach extend to the massive container ships that traverse oceans without refueling, thanks to the energy density of heavy fuel oil?

Complete electrification for such large ships remains a challenge due to the weight and cost of batteries. Instead, a hybrid approach where batteries supplement liquid fuels could be more practical. Recent research suggests two methods: incorporating onboard battery packs that charge at ports, or using dedicated battery vessels that supply power mid-journey.

Integrating Batteries into Shipping

The potential for electrification to reduce emissions and save costs is clear, but how can it be effectively integrated? One option is to permanently install batteries on ships, allowing them to recharge at ports or even at sea. This method mirrors how electric vehicles operate and could maximize the use of costly battery packs.

An alternative approach involves container ships tapping into a network of smaller battery vessels. These vessels would provide power during transit, returning to port to recharge. While smaller battery vessels are already in use, scaling up this system could mimic a scene from the Bond film “The Spy Who Loved Me,” where a submarine is swallowed by a ship.

Research indicates that a container ship journeying from China to Europe could partially rely on battery vessels. From China to Singapore, these vessels could provide power, with the ship switching to fuel for longer stretches where land is sparse. The feasibility of this model hinges on battery prices dropping significantly below A$100 per kilowatt-hour.

Economic Implications

Economically, equipping ships with large battery packs is not currently viable. The cost of implementing 600 megawatt-hours of storage on a New Panamax container ship could reach nearly A$150 million. Such an investment requires regular recharging, which is challenging on long routes.

However, the battery vessel approach offers a more flexible and gradual transition. It allows for deployment in regions with cheaper renewable energy or shorter distances between stops. If carbon pricing becomes more widespread, the economic case for electrification will strengthen, as electricity becomes a more cost-effective option.

As container ships are retrofitted for electrical connectivity at ports, their engines must also be adapted for electric propulsion, potentially sacrificing some efficiency. Given that container ships consume over 100 tonnes of fuel daily, any reduction in fuel costs through electrification could be significant.

Partial electrification not only offers cost savings but could also increase travel speeds by up to 50%, according to research. With battery prices continuing to decline, the financial incentives for adopting electric propulsion could become increasingly compelling.

Future Prospects

The journey toward net-zero emissions in the shipping industry will necessitate a blend of technologies, including clean fuels, efficient engines, and strategic electrification. While the focus has traditionally been on short trips, decreasing costs for batteries and renewables could broaden the scope of electrification.

Should carbon pricing expand, the transition to electric propulsion could accelerate, positioning electricity as the most economical option. While large battery packs for ocean-crossing ships may not be feasible, the concept of off-ship battery vessels warrants further investigation as a promising alternative.