Shipping, Pollution and Technology – Electrification and Energy Storage in Maritime Shipping

In addition to traditional sails and newer rotor sails, electric technologies and energy storage are emerging as alternatives to reduce fossil fuel consumption in the maritime shipping industry.

Electric propulsion and battery storage systems will play a key role in reaching the IMO’s global target of cutting annual emissions in maritime shipping  50% by 2050 from 2008 levels. Big players, from suppliers to shippers to fleet operators, are moving quickly to deploy and commercialize the technology. Although internal combustion engines will remain the standard for the time being, electric and battery technologies have matured enough for use in maritime applications, thanks to advancements in the automotive sector. In addition, continued technology advancements will bring costs down and improve viability of these technologies for maritime applications.

Maritime shipping value chain

Incumbents Delivering Innovation

Innovation in this sector is primarily taking place with incumbents – traditional suppliers are leveraging core competencies and building out new capabilities in electric propulsion and battery storage to:

  • Expand their offering
  • Meet demand for lower-emission technologies
  • Remain competitive in the transition away from fossil fuel-based propulsion.

In addition, suppliers are developing partnerships to leverage expertise in areas outside of their core competency.

Maersk is piloting a 600 kW marine battery system on board the Maersk Cape Town, a 250-meter container ship with a 4500 TEU carrying capacity, to improve vessel performance and reliability. This vessel also includes a waste heat recovery system, allowing battery charging from waste heat. Siemens has developed a suite of electric solutions, led by the Drive LV, a diesel-electric propulsion system for low-voltage drives up to 5MW.

ABB, a leading supplier of electric transportation systems, is developing new solutions for marine vessels. In 2018, ABB signed a memorandum of understanding with Ballard Power Systems to develop a megawatt-scale fuel cell power solution for larger ships. The system leverages and optimizes existing kilowatt-scale fuel cell technologies and provides an electrical generating capacity of 3MW. ABB also recently signed an agreement with SINTEF Ocean to expand the work in fuel cells and test the viability of the technology for main ship propulsion. ABB has been working with the SINTEF laboratory for research purposes, including development of the ABB Onboard DC Grid, which allows for integration of energy storage and fuel cells into onboard power systems.


Investment in maritime shipping innovation
Figure 2. Corporate and venture capital investment activity in shipping and watercraft.

Fuel can represent 50%-60% of a ship’s total operating costs.  As emissions regulations force the use of lower-emitting fuels and place upward pressure on this cost, low-emission technology will become more attractive. Across all sectors, the main drivers for electric propulsion and battery storage are:

  • Emissions reduction
  • Improving performance and reliability
  • Providing redundant power

In the near term, the primary use of energy storage systems is to improve performance, reliability and the efficiency of on-board electrical systems. Battery storage on vessels can provide redundant power and prevent unnecessary use of on-board auxiliary generators by evening out rapid changes in load. The initial targets for hybrid- and fully-electric propulsion are short-distance, smaller vessels with particularly inefficient operations. Two examples of this are ferries and tug boats.


Ferries are initial targets for electric operation, as they cover shorter, fixed routes.  This simplifies charging infrastructure needs and reduces the range needed, compared to larger cargo ships. Battery packs can fully power ferries for their duration of their journey, and predictable routes allow for efficient deployment of shoreline charging infrastructure. Growing demand for passenger and car transport by ferry, particularly in the UK and Europe, is allowing ferry operators to invest in new ships with hybrid electric and battery electric drive systems and new routes. Fully electric ferries can transport over 100 cars and 300 passengers. A ferry fleet can use almost as much fuel as a mid-sized airline.  As such, electric ferries can save millions of dollars in annual fuel costs, allowing fleet operators to recover the higher up-front cost quickly. This segment is growing quickly – 101 battery-equipped ferries are in operation today, with another 76 under construction.

In this segment, electric systems are competing with lower-cost diesel ferries. In some cases, hybrid-electric systems can offer a 35% fuel savings. The switch to battery-electric by Washington State Ferries, the world’s second largest fleet operator, will save 20 million gallons of diesel across 22 vessels. Although still more expensive than diesel vessels, declining battery costs have made electric vessels more cost-competitive, as the vessels will pay for themselves quickly from fuel savings.

Tug boats

Tug boats are also initial targets for energy storage systems. These small boats typically have minimal energy requirements, but they must have enough capacity to aid larger vessels when required. Additional expensive and heavy engines have typically been installed to provide surges in power, but these are rarely used and create additional weight on the vessel. The addition of battery storage would allow tugs to require only one engine, with peak power provided by a battery bank. Tugs could run on battery alone when moving to and from jobs, with a single engine assisting the batteries during surges in power demand.

Drill ships

Onboard installation of energy storage provides peak shaving and dynamic support for diesel generators. The generators typically deployed on drill ships must provide dynamic power demand to ensure the power system remains online, even in challenging conditions. This creates peaks and troughs in electricity demand. However, batteries can store electricity during times of low demand for deployment during periods of high demand, allowing the generators to be turned off and reduce fuel consumption.

Fuel cells

When vessels are operating over long distances, key challenges to use battery electric propulsion are time and capacity to recharge.  As a result, the amount of energy that can be stored by onboard batteries is limited. This creates an opportunity for the use of fuel cells in combination with battery storage. Pilot projects are testing feasibility for fuel cells in ships. The Zero-V project, which involved a fully hydrogen-powered, 10-knot research vessel with 2400 nautical mile range, found  the use of renewable hydrogen dramatically reduced emissions along the hydrogen pathway.. In addition to zero-emission operations of the vessel itself. The research vessel was able to refuel at 4 different ports along the west coast of the U.S., and the project was ultimately considered a success. The most promising applications for fuel cells include low-speed, large capacity vessels, in contrast with the short-distance, high-power applications for battery electric.


Although battery storage and electric propulsion offer an alternative to combustion engines, the latter will remain the norm for some time. Leading suppliers in the industry, such as ABB and Siemens, are developing new products to serve market demand for connected, low-emission technologies and build out core competencies in these areas. Due to the high cost of developing new drive systems for ships, barriers to entry in this segment are high. Startup activity in the maritime sector has remained focused on connectivity and digitization to optimize vessels, routes and port calls.

Keep an eye out for…

My next piece on maritime transportation will focus on connected and digitized revolution in the maritime industry. Many fleet operators have invested in gathering operational data, fueling a wave of startups developing data analytics solutions to optimize vessel operations, routing and port calls. Some startups are using geospatial data to track and analyze ship operations. Increasing digitization and connectedness are providing increased fuel efficiency, compliance and performance audits and operating cost reductions.