Making the transition to shore power
Charging the 'Ampere' ferry
The commissioning of the 'Ampere', the first fully electric car ferry world-wide, operated by Norled, marked the start of the transition of the Norwegian ferry services from fossil fuel propulsion to electrical power, writes Heiko Vrielink, Stemmann-Technik.
The Pilot Project, having a length of 5.7 kilometres and transitting the Sognefjord, has provided convincing results since it entered into service. The Ampere ferry commutes between the locations of Lavik and Oppedal 34 times a day. The ship berths at each of the landward sides and thus the charging systems in the ferry dock 17 times per day. Thus, the charging cycles add up to the impressive number of 6,205 per year.
Compared with a conventionally driven ferry, due to its purely electric drive, the Ampere achieves savings of 1 million litres of fuel per year, thus preventing the generation of around 2,680 tonnes of carbon dioxide and 37 tonnes of nitrogen oxide.
To fulfil these requirements, an extremely reliable, quick connecting and automatic charging system is required. At the ferry docks in Lavik and Oppedal, two systems are in operation. The FerryCHARGER system by manufacturer Stemmann-Technik from Germany is used in around 90% of the docking operations. It takes less than seven seconds to establish contact with the ferry.
The initial charging power of 1,250 A (AC - alternating current) at the start of the operation is increased to 1,650 A by the system. The centre piece of the FerryCHARGER towers is the charging pantograph. Its working range is 3,000 mm in the vertical and 300 mm in the horizontal direction. The movement of the ship (rolling, yamming, pitching, 5° each) is compensated automatically. Furthermore, a remote maintenance system is integrated allowing access to the complete control system, including camera monitoring of on-board or external workplaces.
Now, Norway’s largest ferry operator, Fjord 1 is following suit and is taking the next step in developing purely electric drives for Norwegian shuttle ferries.
At the beginning of 2018, two ferries will start operation on the 2.4 km long stretch across the Nordfjord between Anda and Lote, north of Bergen. Stemmann-Technik was awarded the contract for both the ship and land side chargers.
Based on the experience from the Ampere project and more substantiated market requirements, namely the requirement to realise the charger in the form of a pantograph, a FerryCHARGER system was developed which sets new standards in the field of ferry charging.
The ship-side system is designed as a compact unit and will be installed on the deck of the Anda-Lote ferries. Alternatively, the mounting of these units is possible in the ship's side planking for other ferry models. The pantograph's working range is 4,500 mm in the vertical and 400 mm in the horizontal directions. As on the Ampere, the ship's movements are compensated in a fully automated manner. As soon as the ferry approaches the jetty, the self-sustaining data communication between the ship-side and the land-side charging devices start.
The 3D sensor recognition and PLC control launch the movement of the pantograph to the contact unit. Thanks to the simultaneous landing of the ferry and the establishment of the charging, contact the process is timed optimally. Here the contacting head of the FerryCHARGER pantograph automatically follows the ferry movements.
After successful connection, the special plug contacts of the ship's unit ensure the charging contact with the pantograph. In the event of malfunction, the system is closed down immediately and the contact breaks within a split second so that the connection is interrupted. The charging current for the Anda-Lote ferry is up to 1,600 A (AC) at 690 V low voltage.
Presently, the ferries shuttle across the Nordfjord from 06:40 to 22:00 hours every 20 minutes with longer intervals at night. On the basis of 50 landing operations per day/night, 18,250 charging cycles need to be completed each year which the system must complete without trouble or failure.
On conclusion of the Anda-Lote project, the first four fully electrically driven car ferries world-wide will be charged with FerryCHARGER systems developed and manufactured by Stemmann-Technik. This is just the first important step towards the realisation of emission-free ferry links, others will follow and they are already being planned.
Presently, Norway is a pioneer for world-wide electrification of ferry links. In the call for bids for the lap over the Nordfjord between Anda and Lote, it was specified for the first time that emission-free or low-emission ferries must be used.
This is clear proof of the effect of more stringent governmental environmental requirements. When looking to the future, in Norway alone more than 80 ferry connections could possibly be operated economically using the FerryCHARGER system. In order to do justice to future projects, the system has been designed to supply charging currents of up to 620 A (AC) at of 11 kV medium voltage. With low voltage, the options are up to 3,000 A (AC or DC).
In contrast to the fully automatic FerryCHARGER systems, Stemmann-Technik supplies onshore power supply systems for container vessels and cruise liners, as well as for offshore ships and ro-ro ships which have to be connected manually.
In these cases, the time factor is not as important as for ferries with very short lengths of stay at the pier. Nevertheless, the aims is still to keep the connection procedure as simple as possible in order to impair the port operations in the docking area as less as possible or not at all, thus ensuring a safe and fast connection to the onshore power supply.
Based on the knowledge of many decades of planning and production of various current and data supply systems, Stemmann-Technik also develops custom-fit ShoreCONNECT systems. Stemmann has supplied around 120 cable reels for onshore current containers and the unique onshore current systems for the cruise terminals in Shanghai and Hamburg.
The cruising sector has been experiencing an enormous boom in the past few years. In Germany alone, the number of cruise passengers tripled in the past ten years and no end to this development is in sight. It is definitely true that this industry is characterised by a certain gold-rush atmosphere.
At the same time, it suffers from an undeniable image problem. Ships the sizes of small towns are not really environmentally friendly. A cruise ship spending about 40% of its operating time at the pier, in many ports around the world puffing its exhaust gas directly into the city centres is not something we will ever see on an advertising poster.
The good news is that there are solutions for considerably improving the ports' eco-balance. For example, the ShoreCONNECT system in the Hamburg port spans a distance of 300 metres along the quay edge by means of an underground supply line.
The vehicle is moved by just one person. Once it is in its position, no above-ground lines or other equipment interfere with the port operation. The system is able to compensate a tidal range of 9.5 metres and in 2017, it supplied the AIDA Sol with 11 kV during the ship's 14 landing periods.
In addition, the land-side 50 Hz frequency is converted to 60 Hz for the on-board power system. On 12 August 2017, the MS Europa 2 stopped at the ShoreCONNECT system in Hamburg for the first time and was supplied with 6.6 kV for testing purposes.
The Sky Sea in Shanghai harbour needs to be supplied with the same voltage. However, here the frequency of docking operations is considerably higher. The cruiser moors at the ShoreCONNECT system every three days.
Into the future
Today, the charging current and onshore current supplies are on such a high level that it takes only the willingness to make an investment to make ports and harbours significantly "greener".
Going forward, if we manage to generate our electricity from renewable energy sources, the ferry operators, shipping companies and terminal operators can make a huge contribution to a significant reduction of pollutants and greenhouse gas.