IEEE Electrification Magazine - December 2019 - 24

Figure 1. The Älvfrida, a ferry prepared for battery operation.

1%1%

2% 1%
5%

14%

11%

13%

38%
20%
24%

72%

Energy Industry
Transport
Industry
Residential
Commercial/Institutional
Agriculture
Other

Civil Aviation
Road Transportation
Navigation and Maritime
Railways
Other

(a)

(b)

Figure 2. The impact of carbon dioxide (CO2) emissions on a European
Union-28 sector in 2012. The (a) Global CO2 emissions and (b) transportation sector's specific contribution. Transportation causes 24% of
total emissions, 14% of which comes from navigation and shipping.

automated vessels remains. A slight variance in process
parameters or measurement noise may result in a nonoptimal control function, and even in a loss of robustness for
the controller.

Research Strategy
The prestudy presented in this article was carried out
through a deep literature search and case study with
Styrsöbolaget. The study included an in situ work analysis, the goal of which was to identify barriers and problems faced by the shipping company during the
transition to battery operation and automation. The

I E E E E l e c t r i f i cati o n M agaz ine / DECEMBER 2019

main open issues related to electrification concern its
specific components and charging infrastructure. The
main obstacle from a components point of view is the
present battery technology, which is not yet ready for
operation in shipping. From a charging infrastructure
point of view, the main question that remains is whether
to use a centralized or decentralized architecture. The
automation side addresses issues such as autonomous
docking, fleet trajectory optimization, and monitoring
using new AI technologies, but, another important challenge is identifying the possible gains that can be derived
from automation.

Components Overview
This section provides a general overview of the required
components for the automation and electrification of
maritime vessels. Clearly, part of the equipment will be
located onboard, but part of it must be integrated into the
onshore infrastructure. Any electrical machine needs both
embedded electronic and infrastructure support and, for
this reason, the harbor must have a recharging station. On
the automation side, many sensors and actuators are
required onboard, and a monitoring office will be needed
onshore. This means that the vessel will feature additional
communication devices that have their own criticalities in
terms of the stability of the communication, delay, and
possibility of cyberattacks.

Onboard Electrification Components
As described by Alnes et al., the basic components for
electrification are: electrical motors, battery packs, ac/dc
and dc/ac converters for recharge and power, cooling systems, cables, and safety components. Figure 3 provides a
schematic example, where onboard and onshore components are separated by a dashed line. This list can be considered similar to the corresponding list for a ground
electric vehicle (see Sand et al. 2014), but with different

IEEE Electrification Magazine - December 2019

Table of Contents for the Digital Edition of IEEE Electrification Magazine - December 2019