The source for land-based power may be an electric Utilities and some also possibly a diesel driven generator which depending on land factors and reliable powers sources. Shorepower may also be supplied by renewable energy sources such as wind or solar.
The reasons for using shorepower are concluded such as saves fuel, alternative for allow maintenance of on-board generators, Eliminate emission and some countries to comply with domestic “anti-idling laws”.
Cold ironing as Alternative Maritime Power is the process of providing shoreside electrical power to a vessel berthing while its main and auxiliary engines are turned off. Cold ironing permits emergency equipment, refrigeration, cooling, heating, lighting and other equipment to receive continuous electrical power while the ship loads or unloads its Container, cargoes or passengers.
Cold ironing is a maritime industries term that first came into use when all ships had coal-fired engines. When a ship tied up at port there was no need to continue to feed the fire and the iron engines would literally cool down, eventually going completely cold – hence the term "cold ironing".A ship can cold iron by simply connecting to another ship's power supply – a process the US Navy and other navies have practised for many years – or from a shoreside power source. Recently cold ironing has been looked to as a means to mitigate air pollution by significantly reducing, and in some cases completely eliminating, harmful emissions from vessel diesel engine.
Unlike navy vessels, commercial ships do not sustain long port stays, and stay on power generated internally through diesel powered generators (auxiliary engines). As ships traditionally were not subject to emissions control, since the days of diesel powered ships research was largely focused on using cheaper forms of fuel to run their engines.
As a result ships throughout the world have been using Heavy Fuel Oil – residual petroleum – as the optimal choice of fuel. This fuel, the reverse of gas oils (which are derived through distillation of crude oil), is high on particulate matter; and studies show that a single ship can produce emissions equal to the same amount as 50 million cars annually. Further research indicates 60,000 cardio-pulmonary mortalities due to particulate matter from ship emissions. These deaths have been detected far inland, due to prevailing wind conditions. The total world trading fleet stands at 50,000+ merchant ships (Lloyds data as of January 2008). Each ship spends some 100 days in port in a year.
For every kilowatt-hour (kW h) of electricity, about 200 gm of bunker fuel is consumed. Each 1kg of bunker oil =3.125kg of carbon dioxide. It is assessed that globally ships use 411,223,484 tonnes of fuel annually.
Keeping these reports in mind, new regulatory norms have been mandated by the International Maritime Organization (IMO). The level of sulphur is one of the benchmarks in measuring quality of fuel and Marpol Annex VI requires use of <4.5% sulphur fuel, effective 2010. The target is to reduce world maritime sulphur output to <0.5% by 2020. Some regions (e.g. California) already require ships switch to cleaner fuel when in their local waters.
Cold ironing does away with the need to burn fossil fuel onboard ships while they are docked. In this concept, ships visiting ports are hooked on to local grid power – or other – power sources which are already regulated by local pollution norms. This shore-sourced power serves the ship’s cargo handling machinery and hotelling requirements. Effectively, all generating sources are shut down and ship is hence cold-ironed. This brings immediate relief from pollution by shipboard emissions and allows a more holistic maintenance schedule to be followed by ship operators, which are typically hard put to maintain planned maintenance schedules due to commercial operating pressures.
Concern and Restriction
Ships, built in diverse international yards, have no uniform voltage and frequency requirement. Some ships use 220 volts at 50 Hz, some at 60 Hz, some others use 110 volts. Primary distribution voltage can vary from 440 volts to 11 kilovolts.Load requirement varies from ship to ship and ranges from a few hundred kW in case of car carriers to a dozen or more MW in case of passenger ships or reefer Ship. Connectors and cables are not internationally standardized, though work has progressed in this direction. There are other legal implications to outsourcing primary power source. All these problems are addressable and work has already begun in reducing ship emissions by cold ironing
Different power forms may be used to transfer electrical energy from port to the ship/vessels: 11000 V AC / 6600 V AC (likely to become standard) / 660 V AC / 400 V AC
High voltage reduces the mass of the cable, and so reduces handling labor. One obstacle is the use of different frequencies like 60 Hz instead of 50 Hz. Which may cost 300 000 - 500 000 EUR to convert. The amount of power for an ocean-going ship is usually 2,0 - 10 MW. Cable to connect larger ships may cost 20 - 25 EUR/meter. Transformer substations cost 15 000 - 30 000 EUR. Operation and maintenance costs of the onboardMWh for electricity generated. Fuel cost for sea diesel, with sulphur content less than 0,5% cost approximately 18 EUR/MWh (12 months sliding average in 2005).
To ensure that galvanic corrosion doesn't occur an isolation transformer that provide galvanic isolation should be used, because the power grid and on board earth potential may differ.
Connecting or disconnecting takes approximately 30 minutes using 400 V AC due cable bulkiness. Thus increasing the voltage and put a portable transformer at the end might be worthwhile for the benefit of less cable area. This affects the minimum amount of time required shore time to make it worthwhile.
Case Study : The Port of Shanghai use a movable 2000 kVA shore power supply system with AC drives to supply electricity from the national grid to the ships in dock.
So far a few ports in the world have adopted a shore power supply system for docked ships, meaning that ships are supplied with low-emission, noise-free electricity from the national grid through a shore power box and a link cable.
An important import and export base for goods in China, the Port of Shanghai, which is the second largest port in the world, uses a 2000 kVA shore power supply system with Vacon AC drives, capable of converting the 10 kV shore power into 440 V/60 Hz or 380 V/50 Hz high-quality clean power for the ships in the port. This solution is not only good for the environment but also gives other benefits such as a low level of noise, low power consumption and vibration, high efficiency, accuracy and stability of the power supply, and has a long life.
Satisfying various application requirements
At present, an average of nearly 170 large ships as well as numerous small ships dock in Shanghai port every day. The grid standards used on ships coming from all over the world differ from each other. Many ocean-going vessels have a 440 V/60 Hz 3-phase, 3-wire system, while a 380 V/50 Hz 3-phase, 4-wire system is used in China. Since the wrong power supply can damage marine equipment, the shore power supply system is used to convert shore power to ship power, and to provide power for ships using various grid standards.
The annual import and export trade through Shanghai, in terms of value, accounts for a quarter of China’s total foreign trade. In 2009, the Port of Shanghai ranked the largest in the world in terms of cargo throughput and was the second largest container port.
Shore power supply systems can cut costs considerably. Based on an oil barrel cost of USD 80, the annual savings for a cruise liner can be up to EUR 400,000. If one port includes a shore supply system, the annual savings for a container ship can be up to EUR 150,000, and if 15 % of ports include shore supply system, the annual savings for a container ship can rise to EUR 500,000. In Europe, the ports in Kemi and Oulu in Finland, Gothenburg in Sweden, and Lübeck in Germany have a shore supply system.
Reliable products and outstanding control
A key component in the design of the 2000 kVA shore power supply system at the Port of Shanghai was the Vacon NXP AC drive, featuring coated PCBs, a compact structure and high control performance. In addition, it conforms to ABS and DNV standards.
After the Vacon NXP output is filtered by a sinusoidal filter, a pure, smooth alternating current is supplied to the ship through a special flexible cable reel. To prevent the impact of inductive loads and startup currents, the voltage converter monitors variations in the voltage in real time, and the PID controller compensates for any voltage drop within milliseconds. In addition, the powerful software programming tool Vacon NC61131 also plays an important
Reduced carbon emissions in future
Ships need to burn a large amount of heavy oil or diesel to maintain normal operation while in dock. Data shows that port cities produce 25 % more exhaust emissions than other cities because ships run their generators while in port. For instance, 93.3 tons of harmful substance, such as lead, and 31,000 tons of CO2 are emitted by the large ships in Shanghai port every day.
The 2000 kVA shore power supply system developed jointly by Shanghai port and its partner Wuhan Guide has shown unprecedented technical benefits. Implementing this technology for all the large ships in the ports of the Shanghai Port International Group (SIPG) will eliminate the emissions of at least 33,800 tons of harmful substances and 11,3150 thousand tons of CO2 annually and save 366,000 tons of standard coal. SIPG has filled a gap in the international shipping industry, and in future this technology can be expected to become an international standard.
In the future, moreover, the converter power application derived from the shore power voltage technology will have a more extensive application area, such as the power supply for medium-frequency heating furnaces with 400 Hz medium-frequency AC current, and for temperature rise testing of motors and generators using adjustable frequency and voltage. Compared to conventional devices, it has significant advantages such as a small volume and low noise and costs.
Summary.
Malaysia ports are understudying the demand and practicability to provide shore power supply in its facilities. As mentioned above, the restriction to covert mainland power to ship power and the investments to build the system will be major challenge to ports in Malaysia. Major of ports are operated by private companies which are focusing on the operation efficiency and business development while Port Authorities are less emphasize sustainability in the Port Development Plan. Environment and sustainable development seek integrated plan and implementation from both parties in line with the evolution in Maritime industries and The Government commitment to reduce carbon emission by 2015
Ahmad Mansor Sa
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