Delivering charging capabilities in ports and harbors means installing infrastructure for vessels and onshore equipment with reliable, high-performance systems – and the grids to support them
The installation of shoreside charging infrastructure is essential for the futureproofing of ports, and key to helping them transition to cleaner marine applications. Rebekah Keeler, head of cruise at Associated British Ports, believes an important lesson from installing shore power technology has been that each installation needs to be uniquely designed for each port.
“At the UK’s Port of Southampton – where ships can plug in at the Horizon and Mayflower cruise ship terminals to achieve zero emissions at berth – power cables are placed under the quay so they don’t impact other operations that may be taking place at the terminals,” she says.
Laurent Dupuis, vice president of product management – shore power and ports and maritime at Cavotec, says the challenges are economical and organizational, as well as technical. “Shoreside charging systems require stakeholders that were not solicited before – for example, energy producers, grid operators, high-power electrical system suppliers – and existing stakeholders need to learn new domains and new constraints,” he says. As a result, there is a need to redefine the roles and responsibilities for the installation. Often, shore power must be a multistakeholder endeavor.
Jan Egbertsen, manager of innovation at the Port of Amsterdam, thinks of the port as a matchmaker in infrastructure programs. “Where we have to, we are willing to invest to show it can be done,” he explains. “All of our onshore power supply (OPS) waiting places in port and in the city have OPS with a 25MW installation under construction to serve one or two sea cruise vessels or river cruise boats.”
With the typical traffic experienced by major ports consisting of small and large vessels, mixed demand and vessel charging needs can prove challenging.
“For low-voltage systems, we only have a publicly available specification with no agreed standard,” says Christian Moe, project manager at Plug, which is working on an OPS installation for cruise vessels at the Port of Narvik in Norway. “We believe the cost of installing high voltage also favors low-voltage connections for smaller cruise ships, and have several examples of smaller cruise vessels, using low-voltage connections, able to use the same infrastructure as the offshore supply vessels, only with more plugs.
“For all ships, we need a flexible cable management system (CMS) to accommodate differently placed connection hatches. In the design of the CMS, we have to consider the capabilities of the quay and other activities on it at the same time.”
Knowledge is also key. “To maximize utilization of the shore connection, you have to know what ships are arriving in port, their capacity and measurements, in order to serve them correctly,” Moe explains.
Sarah Fear, knowledge exchange and project manager – clean maritime at the UK’s University of Plymouth, believes marine charging infrastructure is still an emerging picture.
“There’s a broad expectation of different vessel types – leisure or commercial – and sizes, and the duty cycle, which is probably the most important thing,” she says. Battery current and charging elements that suit fast-charging also play into this broader landscape, but even mooring location can have a role.
“Some of this depends on where the berth or mooring is,” Fear says. “Is it openly available or is it closed off to only one person? Lots of subsets compound each other to build this complex picture.”
“The challenge has been and always will be to establish a suitable utility connection for the proposed infrastructure,” says Alex Bamberg, CEO of Aqua SuperPower, which installed the UK’s first marine charging network around Plymouth Sound National Marine Park. “We carry out an analysis based on vessel requirements and prospective dwell times versus charging speeds, which determines which solution we propose to deploy. This also determines the sizing of the utility connection.”
Aqua SuperPower’s marinized charging infrastructure can dispense up to, and over, 350kW per plug. When these systems – designed for the high-power CCS standard already used on electric road vehicles – are clustered, multimegawatt charging becomes a reality.
Much of the technology has been adopted from road vehicles but requires adaptation to meet the demands of the marine environment. “Most notably, there is a need to marinize the charging solution, involving enhancing the IP rating of the charging unit to IP67, and the need to enhance the socket from IP54 to 67. Other considerations relate to charging cable lengths,” says Bamberg.
Moe explains that all cruise ships are supplied with AC rather than DC power, and those with batteries installed have their own converter on board. “There is a lot of work being done in developing standards for larger vessels, and the size of the battery and the charging time are decisive for the solution,” he says. “Ferries in Norway have DC supply, but these are systems built for the specific vessel. There are few, if any, ‘open’ DC chargers for larger boats. Smaller boats, with car-sized batteries, charge using CCS.”
Bamberg considers that, practically, six would be the maximum number of sockets that could be physically handled on a single vessel. “There are other methods to dispense electricity quickly, such as pantographs, specialized OCC three-pin connectors and automated charging systems, but these are highly specialized solutions and vessel-specific applications,” he confirms.
Cavotec’s charging solutions usually range from 200kW (in low voltage) to tens of MW (in medium voltage) per connection point.
“The maximum power is difficult to define because our product can be customized,” Dupuis confirms. “We are currently at 12MW but systems can provide even higher power and the systems we propose are not the same across the whole power range.”
Above 1MW, charging systems are usually automated, but new advances are changing this. Cavotec’s recently announced Megawatt Charging System (MCS) will be able to provide up to 3MW of DC power from a single connector with grid-to-inlet functionality.
“We are reaching charging performances of around 3.0 and possibly 4.5MW in one connection that can also be handheld,” says Dupuis, who cites opportunities for standardization that would address the diversity of vessels and shoreside sites. This includes system use for land vehicles, which would help ports have all the same infrastructure on the same network.
Automated charging technology, meanwhile, benefits the short turnaround of ro-ro ferries where plugging in can be unfeasible.
“Automated charging systems can allow greater flexibility and choice for the designed location of the on-vessel charging inlet, reducing human intervention,” says Rhona Macdonald, the British Ports Association’s sustainability advisor.
Dupuis believes wireless charging could also be very useful. “However, the power transfer capacity still appears too limited to be widely adopted, and the size/power ratio is not always compatible with the available space on-ship or on-shore,” he says.
Other infrastructure charging requirements such as e-vehicles and e-cranes can be managed on the same microgrid as e-vessels, but this depends on many factors and no one-size solution fits all.
“If a port is designed and operated as an EV transportation hub, and the criticality of the different operations allows it, then it can make sense to have the different charging systems on the same microgrid,” says Dupuis.
Investment in the grid technology depends on what needs power. “With barges and river cruises, it’s really proven technology. Investment isn’t that high; the only thing needed is a grid connection and enough capacity on the grid,” says Egbertsen. “Usually in and around the port area, we can invest ourselves because we own the quaysides. With seagoing vessels, the terminals and shipowners will have to invest in OPS. The 2030 EU Alternative Fuels Infrastructure Regulations that require potential mandatory OPS for inland and seaports will push things ahead,” he adds.
Increases in MW capacity also demand extra grid connections. “A technical requirement is making local grids capable of delivering the high power needed, which can be 10-100 times higher than usual requests,” confirms Dupuis.
“Grid-related considerations – in terms of capacity, stability and energy source – must be addressed as preconditions for the implementation of shore power connections and, at the moment, the extremely high capital costs associated with expanding grid capacity are a deterrent for installation,” explains Macdonald. “Many UK ports are already at their absolute limit. Large vessels will require in the order of 5MW per connection, which could be a quarter or half of the typical demand for a small or medium port.”
These grid connections will put stress on local energy networks, requiring significant capital expenditure on reinforcement or alternative energy storage.
“Ideally, marine systems will integrate with distribution grids in a way that is commensurate with the integration of on-land technologies using the grid,” says Dr Matt Knight, principal technical specialist in technical innovation, energy systems and infrastructure, at Cenex. “Increasingly, this will be via connected systems as part of a smart and secure grid system, meaning electricity generation and demand can be optimized to maximize efficient usage, reduce costs and carbon, or to manage other conditions such as system constraints.”
Other solutions to help manage local grids include exchangeable energy containers for inland barges. Zero Emission Services’ ZESpack 6.1m containers are charged with green electricity, and swapped when depleted at open-access network stations. They can be used to stabilize electricity grids or supply temporary local demand.
Virtual bunkering using bidirectional charging systems can also benefit the grid.
“On a national level, this enables more battery storage on the electricity network,” says Bamberg. “This enables greater integration of renewable energy technologies through balancing their intermittent generation, adding energy security and balancing the grid.”
On a local level, this can enable operators to effectively be part of a microgrid, which enables a site to protect itself from energy price volatility and have more renewable energy on-site. “Longer term it is likely that chargers, batteries and virtual bunkering will help to form DC microgrids that will help harbors, ports and marinas decarbonize all on-site activities,” Bamberg concludes.