TT Talk - Sure power to meet expectations
Shore-based power supply for ships is not exactly new, but may be becoming a ‘hygiene factor’ as stakeholders grapple with broader societal expectations in relation to environmental performance and protection.
This article sets out a discussion between Oscar Egerström (“OE”, Underwriter, TT Club) and Roberto Bernacchi (“RB”, Shore-to-ship power & Smart Ports Global Product Manager, ABB) on shore-to-ship power supply.
OE: As we start out, perhaps you could provide a short introduction to those who are less familiar with the topic?
RB: When a ship berths at a port, there are numerous on-board systems and services that continue to require auxiliary power, both in relation to crew and other people (whether passengers or stevedores), as well as cargo management (such as temperature controlled commodities). Shore-to-ship power enables the ship to switch off its propulsion systems and connect to the local electrical grid. Upon port arrival, an on board cable management system consisting of two extension cords is connected to the electrical junction box installed on the berth. The ship power management system will then switch off the auxiliary diesel generator and transfer the supply of the residual ship loads to the shore power.
“Shore-to-ship power enables the ship to switch off its propulsion systems and connect to the local electrical grid”
OE: Shore-to-ship power supply has become a hot topic for the ports industry. There are legislative moves, such as the EU directive on sulphur emissions, and increasing societal pressure on ports and all the maritime world to be improve environmental performance and be responsible towards their surroundings. In that context, why is shore-to-ship power supply becoming so relevant?
RB: Reduced emissions are the ultimate goal of shore-to-ship power solutions, yet another important benefit is to reduce noise and vibrations, to create a better environment for passengers, crew, dockworkers and local residents. With global (IMO / MARPOL), regional (European Union and North America emission control areas) and local (California, China, Norway) governing bodies issuing and enforcing regulations or incentive plans to limit sulphur oxide (SOx), nitrogen oxide (NOx) and carbon dioxide (CO2) emissions by the shipping industry, we are facing a consistent growth of shore-to-ship power infrastructures.
The presence of a global standard for high voltage shore connection in ports (IEC /ISO / IEEE 80005) has ensured full interoperability of onshore and on board systems, allowing implementation on a global scale.
What to consider
OE: Recognising that there are various drivers to establish shore-to-ship power supply, what should a port consider?
RB: There are several factors to be taken into account in designing an effective solution, including:
- Overall power availability at port substation
- Type of ship to be supplied
- Nominal power supply for each ship
- Average power for each ship (utilization factor)
- Multiple ship operation (contemporaneity factor)
Careful planning of the shore-side infrastructure is necessary to allow the maximum number of connections in line with the overall port grid capacity and the current / future customer requirements.
“Careful planning of the shore-side infrastructure is necessary”
OE: Once a port has decided to establish such facilities, what infrastructure needs and investments are typically required?
RB: These will vary considerably depending on the type and number of simultaneously connected ships . From a pure investment perspective, the overall cost of an infrastructure spans from a few hundred of thousand euros for a low power consumption ship single connection to several million euros for a high consumption ship facility (cruise or container terminal), as a function of number of ships simultaneously connected.
High power consumption ships may require a specific agreement with the electrical grid operator or distributor to enhance the port grid capacity. Additionally, a new power substation facility at port side will typically be needed, potentially including a static frequency conversion system where the national power supply is 50 Hz considering that most ships operate at 60 Hz. From the substation output, it is necessary to create a distribution system to shipside, including related cabling, cable ducts and trenches. Commercially, the port has to engage with the ship customers to ensure a high utilization factor.
Risks to mitigate
OE: Once the facility is in place, what are the operational requirements (e.g. personnel numbers and training) and what risks need to acknowledged and mitigated?
RB: Ensuring the highest availability to the ships calling at the port is key, specifically when the same facility serves different operators / ships. This will include an effective maintenance schedule.
The operational impact will depend on the level of automation. It is possible to avoid shore personnel support, relying on trained electrical engineers on the ship to operate the cable management system via remote control. Bringing the cable on board and the switchover to the port grid supply can be performed seamlessly with a dedicated control panel in the ship’s engine room. Advances in automation can preclude direct handling of the connection plugs, enhancing the overall safety level of the facility and particularly benefiting ships docking for short periods. However, manned operation is still required in many situations, whether due to local work safety regulations or more complex ship operations, such as container or cruise ships.
Risk mitigation procedures need to be carefully defined, particularly where human intervention is necessary, and, while the electrical system should be designed to the strictest health and safety standards, operator training remains key to make sure that connection happens in full coordination between on board and shore-side based personnel.
“Risk mitigation procedures need to be carefully defined, particularly where human intervention is necessary… operator training remains key”
We gratefully acknowledge the assistance in the preparation of this article of Roberto Bernacchi, Shore-to-ship power & Smart Ports Global Product Manager, ABB