Outfitted with power and energy management systems, remote monitoring, batteries and Azipods, new hybrid-electric ferries will be easier to operate, have lower emissions and cut fuel consumption
When P&O’s two new 230-m long ferries start plying one of the busiest and most technically demanding routes in the world in 2023, their bridge and enginerooms will rely on ABB hybrid propulsion.
And as the largest passenger and freight ferries ever to sail the English Channel’s 34-km crossing, they will need it.
“For P&O, safety and efficiency are the key drivers,” ABB Marine & Ports global segment manager for ferries Palemia Field tells Passenger Ship Technology. “They are operating in some of Europe’s most congested waterways [and that] means a substantial workload on people.”
That is why, according to both parties, P&O went for an ABB-supplied bridge-to-propeller hybrid integration solution that cuts emissions, saves on fuel and speeds up sailings, with the battery system taking over much of the load in port as well as helping out at sea.
“All this proved decisive in selecting the hybrid solution for the new ferries,” says P&O Ferries.
ABB’s Power and Energy Management System (PEMS) sits at the heart of the bridge-to-prop configuration. Closely integrated with the electrical system, it is the brain that ensures the most efficient deployment of the vessel’s total power resources. And it does so by filtering and directing the flow of information across the shipboard systems according to need.
Four of ABB’s 7.5-MW electrically powered Azipods provide the main propulsion for each vessel. For extra boost, Power2 turbochargers will be added to the engines. The turbochargers have been cleaned up to a point where they reduce up to 60% of NOx emissions and contribute towards 5% in fuel savings.
Remarkably versatile, the Azipods rotate 360° to increase manoeuvrability and operating efficiency, slash fuel consumption by up to 20% compared to traditional shaftline propulsion systems, and for good measure run quietly with little vibration.
From the outset, P&O asked ABB to take under its wing the total cost of ownership for all the propulsion elements. “This shifts the integration responsibility to us as the manufacturers,” says Mr Field. “ABB’s remote monitoring solutions will support the crew and shore staff in forecasting maintenance needs, as well as more in-depth planning for scheduled maintenance. It will also identify operational changes that could save energy.”
In something of a surprise, America’s XALT Energy will provide the high-performance battery system in a breakthrough for the group. A specialist in the manufacturer of lithium-ion cells and battery systems for medium-heavy duty markets, the group has previously focused on smaller vessels such as 20-m workboats and public transport – its batteries drive more than 10,000 buses.
XALT Energy’s electric system will be worked hard. “While the decision on how much the batteries will be used lies with the owner, it is envisaged that the ships will be able to operate efficiently using hybrid technology in port and at sea,” explains Mr Field. “The batteries have been designed for load levelling and to minimise generator running hours both in port and at sea. When shore charging becomes available, the vessels will be capable of zero-emissions port calls.”
In shore-charging, the vessels will be ahead of the game. They will be ready to go with ABB systems, including the onboard cubicles necessary to pull power while in port, but the rest is up to the port authorities who have yet to install the essential infrastructure.
Ferry operators are still learning a lot about how to use stored energy – and the chief engineers on the P&O vessels will be in the thick of the action. As ABB’s ferry expert tells PST, “The most challenging aspect to operate for any chief engineer on a hybrid system is the use of stored energy. For decades we have worked on the premise that we must have a reserve of power on the engines to maintain redundancy during difficult manoeuvres or in limited waters. Naturally, the batteries will provide this reserve.”
But there is a bigger issue – namely, extending the working life of these costly systems – and this is where intelligent systems come in. “How do we protect the lifetime of the battery and allow them to perform in the best possible way over a longer time?” says ABB’s ferry expert. “PEMS allows us to set different modes while still taking in strategic loading advice for the engineers on board. Outputting data from PEMS to the ABB Ability Remote Diagnostic System for Marine allows ABB and P&O to monitor the longer-term operation of the batteries to give data-based recommendations for operation.”
In yet another contract snapped up by China, Guangzhou Shipyard International will build these double-enders. With a pair of Azipod units and a bridge at each end, there will be no need to turn the ships in port. The captain and senior officers will simply walk to the opposite bridge, saving seven minutes on each outbound and return journey and a useful one tonne of fuel – a sixth of normal usage on the 34-km crossing.
The vessels will also feature ABB’s intelligent manoeuvring and control system, the ABB Ability Marine Pilot Control, that takes some of the decision-making out of the hands of the officers. The idea is to automate some navigational tasks and leave the bridge to focus on the main task. That is, optimising the overall control and positioning of the ship.
But exactly what tasks are automated? “By simplifying ship control with a single input, the officer of the watch and master are able to input ship vectors – that is, where they want the ship to go,” says Mr Field. “[That allows] ABB Ability Marine Pilot Control to work out the necessary commands to each of the four Azipod propulsion units on board.”
This is much superior to the alternative, according to Mr Field. “This would require people to input individual instructions to each Azipod unit. By focusing on managing the bridge resources, our intent is to make a ship like this simpler yet safer to operate. The bridge staff are free to maintain their situational awareness.”
Clearly, not an unimportant consideration on a route used by more than 500 ships a day.
Unsurprisingly, demand for the manoeuvrability offered by Azipod-assisted propulsion is growing strongly in the global ferry industry that carries around 2.1Bn passengers, 250M vehicles and 32M trailers every year. As a bonus, Azipods open up more revenue-earning space because, being located outside the hull, they leave more lane metres.
And on these highly competitive routes, every bit of extra revenue helps.