Historically, ‘cold ironing’ is a US navy term derived from the fact that once the on board gensets have been stopped, the iron/steel mass of the whole engine room gets “cold”! Shore power has attracted a lot of attention recently as a way to reduce emissions at two levels:
local diesel engines emissions which are increasingly considered as a public health issue for the populations located around port areas,
global shipping industry CO2 emissions, as part of the numerous corrective actions identified to reduce climate change risks.
Ideally, as illustrated in figure 1, shore power could become a fully optimised extension of the shore power network towards the vessels at berth, by allowing ships to get connected to lower emission – lower cost power sources.
The shore power economical challenge
Figure 2 illustrates the possible strategies ship owners could have on this market, taking into account the typical hour by hour, week by week, fluctuating price of the on shore power market.
As an example in this figure, we have set this onboard generation cost line in the middle of the typical hourly shore power market price. This means that during day peak hours, when demand by other (shore based) consumers is high, shore power price is significantly higher than onboard generation, and that a ship owner’s interest is to keep his gensets running…conversely, during low demand period, typically at night, his interest is to switch to shore power to get access to lower cost sources of energy. Unfortunately the reality is presently quite different, and there are some ship owners and terminal operators who currently may comment ‘off record’ that shore power is just a fancy gimmick invented by some ‘greenish’ bureaucrat from the Californian Air Resource Board (or even worse the European Commission..!) to kill their profits. (figure 3!)
This may be seen as a cynical view but such statements should not be neglected by any shore power promoter, as it reflects the truth: in most cases, shore power is not profitable for ship owners, and out of the 60 000 +merchant vessels currently in operations worldwide, only a couple of hundred are using it, a clear indication that it is not a profitable operation. In fact, while reviewing CO2 emissions reduction strategies, Det Norske Veritas class society recently ranked shore power as one of the least efficient CO2 emissions abatement technologies, behind no less than 20 others. Nevertheless, several factors, beyond mandatory requirements, may change shore power use, as identified in figure 2:
– On board (diesel) generation fuel costs may rise sharply if oil barrel price rises and if, as is already the case in some areas, use of low sulphur fuels becomes mandatory;
– Conversely as identified in figure 4, the development of Liquefied Natural Gas (LNG) as a fuel for the shipping industry could become a very attractive solution against shore power;
– On board generation price may as well increase if local or global emissions taxes are implemented;
– Subsidies, especially to cover the ship owner’s and terminal’ s expenses may be implemented (and has been in most present cases for Capital Expenses, but Sweden is, for example, considering to deliver shore power tax free to make it competitive for the long term), but cannot be considered as a long term solution;
– And last but not the least, in the long term, the shore power industry can increase its competiveness by reducing, through innovation, its Capital and Operational Expenses, as NG2 is proposing with PLUG.
PLUG shore power solution
PLUG (Power Generation during Loading & Unloading), is an innovative solution to drastically increase shore power competitiveness, both in terms of economical and environmental benefits. It is game changing technology based on a very innovative connector system, leading to much easier and efficient operations: as soon as the vessel is at berth , the crew simply has to slide out a beam above the quay, to which is attached the ship side power socket and drop a chain toward the quay side connector.
The chain is equipped (figure 5) at its end with a triangular cross section shuttle bar, which as soon as it is within reach, is grabbed by a diaphragm system which guide it towards the quay side connector . Getting further down, inside the connector, the shuttle bar gets into contact with a set of three rollers which force it to rotate and get indexed with the connector electrical contacts. Further down, the shuttle bar slots into a mechanism which locks it with the connector. The diaphragm can then be re opened and the crew can hoist up towards the ship side socket the quay side connector and the power cables attached to it (see figure 6).
When it gets into the ship side socket, the shuttle bar is guided by another set of three rollers and rotates again to align in front of each connector and socket electrical contacts. When the connector gets further up, the socket electrical contacts push open the quayside connector contacts and the connection is established. These unique features make PLUG the world first solution to perform a safe, multi mega watt, high voltage, connection in less than a minute. Another feature is that the power exchange capability can be optimised to meet with the same design, and a single PLUG unit, most of the world’s fleet requirements, under up to 11 000 Volts, as illustrated in Figure 7.
This means for example that, as illustrated in figure 8, a single PLUG unit can cover the power exchange requirement of most container carriers up to 8000 TEU. Only the larger ones will need to install two PLUG units in parallel to fulfill their needs, using two adjacent quay side PLUG interfaces (Fig 9).
Application to container carriers
The container carrier case is certainly one of the most challenging for shore power, as it competes here with other potentially very cost effective solutions to meet CARB or general CO2 emissions reduction requirements, such as on board gas power generation. Taking advantage of PLUG compactness, we propose to install it (see figure 10) within the side passageways which are fitted along container carriers above the side ballast tanks, preferably at the level of the Engine room main switch board, to reduce the length of the routing of HV cables between PLUG and the vessel’s main switchboard, reducing installation costs and duration. Other benefits include simplified mechanical installation as the PLUG interface can be fitted directly within the vessel’s existing steel structure. A key saving compared to manual connector solutions, which requires two cable reels for power exchange in excess of 4 MVA, is that a single ship side and quay PLUG unit can provide up to 6 MVA. This drastically reduces ship side installation costs for vessels requiring between 4 to 6 MVA. As mentioned above, for power exchange above 6 MVA, another PLUG unit can be used in parallel, installed in the side passageway, in front of the next quay side shore power interface. This offers a power exchange capability of up to 12 MVA without any significant additional cost for the terminal infrastructure. On the terminal side (see figure 11) the PLUG interface will be a sliding basket located just above the water alongside the quay, so that the HV cables can festoon under it under the water. Although rudimentary, this is very cost effective and reliable cable storage and management system, taking advantage of the available volume created by the quay side fenders between the quay and the vessel sides. In terms of operations and safety (see figure 12) PLUG has a negligible quay side foot print and does not require shore side operator, so impact on the (cargo and others…) operations and safety hazards are kept to a minimum.
PLUG Project Status
PLUG has been officially released on the market at the September 2010 Shipbuilding, Machinery and Marine technology fair in Hamburg, where a full size PLUG was on display, demonstratin
g, among other features, its one minute connection/disconnection capability.
In parallel:
a PLUG /AMP adaptor is developed to propose PLUG for California Terminals already equipped with AMP, (see figure 13). Due to the gains it brings in terms of speed of operations and reduction of man power costs, such an adaptor is expected to require a return on investment period of one or two years for the terminal operator.
California emission abatement requirements
The first benefit of PLUG technology would be increased levels of safety when compared to traditional methods currently in use. Secondly, PLUG would bring benefits in terms of public health, as PLUG, by allowing to connect the vessel to shore power from the first to the last minute of its call, without requiring any quay side operator who may generates extra delays if they are not readily available, will increase the duration of the effective connection to shore power, leading to the corresponding further gains in emissions reduction. With regard to short duration calls, CARB, certainly based on manual connectors limitations, has exempted vessels docking for less than three hours, this could be reconsidered with PLUG, down, let’s say to half an hour, leading to further emissions reductions. This possibility to increase the rate of use of the whole terminal side shore power infrastructure should be especially attractive for ports which are in a second port of call situation, having shorter berthing time, such as Oakland for example. Thirdly, PLUG technology would achieve higher cost effectiveness for port and terminal operators, as PLUG reduces drastically the man power costs and the capital expenses while increasing the rate of use of the whole infrastructure by 20 %.
Conclusion
By mixing “California” and “innovation” within the same question, the title of this paper was certainly making the answer an easy one: there is room for innovation to meet Californian shore power requirements. The author’s opinion would go even further by stating that there is not only room, but that there is a need for shore power innovations to makes this solution competitive compared to other technologies, especially onboard gas fuelled power generation, and PLUG is certainly only one of them!