An intense debate is currently taking place internationally regarding the future of the use of electricity as a source of power for ships during their stay at port. In this article, we will discuss different aspects related to this, including the advantages and disadvantages of its implementation and the alternatives which can currently be used. But, what´s OPS?
Also called Cold Ironing, Alternative Maritime Power (AMP) or Shore-to-Ship Power (SSP), OPS or Onshore Power Supply consists in connecting the vessels to the terrestrial electrical network while they are docked at port, so that their auxiliary engines can be off during de loading and unloading of goods or persons. Currently, they use the energy from their auxiliary engines to maintain the operation of their on-board equipment: transfer pumps, refrigeration systems, lighting, emergency equipment, etc.
Combustion of heavy fuel oil in these auxiliary engines emits large amounts of Nitrogen and Sulphur oxides, particulate matter and carbon dioxide to the atmosphere. Several studies have shown that these compounds are very harmful to human health, as they are directly linked with the development of cardio-pulmonary diseases (Mortality from Ship Emissions: A Global Assessment – J.J. Corbett).
Given the fact that ports are usually surrounded by densely populated areas, OPS appears as an opportunity for improving the current energy model. The implementation of OPS systems reduces pollutant emissions in the mix of emissions associated with the national electricity market. In addition, delocalizes those emissions away from ports, and consequently the cities that surround them. In addition to reducing pollutant emissions, so damaging for the surrounding population and the environment, it is also possible to completely eliminate the noise associated with the operation of the engines. This is a clear advantage for the population of areas close to port facilities.
Options to reduce emissions
The emission reduction achieved is drastic: 96% less of NOx, 36% of SOx, 68% of particle matter and 45% of CO2 (taking into account the Spanish mix of electricity of 2015). Additionally, as renewables energies gain ground in the state energy mix, this reduction will continue growing.
Because of all this, the installation of OPS systems is one of the strategies recommended by the World Ports Climate Initiative to reduce the emission of greenhouse gases and reduce its harmful effects to the population and the environment. In addition, the European Directive 2014/94/EU, regarding the deployment of alternative fuels infrastructure, refers specifically to the supply of electricity for vessels while docked at port. Consequently, each Member State must develop a national policy framework for OPS deployment, which should analyse the necessity of implementation of this technology.
In addition to this directive, other international standards invite ports to take OPS into consideration (see MARPOL 73/78, Annex VI, Directive 2012/33/EU, as regards the sulphur content of marine fuels, or Directive 2008/50/CE.At national level, a 50% cut off on the T-1 port charge has been approved for docked ships using electric power during they stay (General State budgets for 2016, Final disposition number 23).
Therefore, why is Onshore Power Supply not implemented in all ports already?
There are two main reasons why this system is not currently universally installed:
- The first one is that in most ports, the installed grid does not have sufficient capacity to provide vessels with the power they need and local electricity networks do not usually reach the point of connection at the quay. It is therefore needed to expand the local grid, which is costly in most cases.
- The second one is that ships are not usually adapted to be connected during docking. This adaptation, although of small size, also requires investment by shipowners.
On the other hand, and it should be emphasised, there are technical solutions for the implementation of OPS, so technology does not represent a barrier at present. The following diagram shows the basic structure of an OPS system:
But nevertheless, it is necessary to take into account different conditioning factors when designing an Onshore Power Supply System:
- Which quay(s) should be equipped? What vessels should be supplied?
- What power needs the installation to be dimensioned for? What demand can be expected?
- What technical specifications must the system comply with in terms of voltage, frequency and power supply?
- How to cope with investment? How to plan it? Which will be the return of investment?
Undoubtedly, OPS has arrived to remain in port’s energy management, so when planning the installation, it is necessary to have specialists in the field, who have the necessary information and knowledge to answer the above questions correctly to optimise the potential of the installation.
In line with this, Inova’s Energy Transition area has developed the study “Measures for the provision of electricity to ships in ports of general interest” at the request of Puertos del Estado The study’s main objective is to assess the need for implementation of Onshore Power Supply in Spanish ports. For this purpose,the GRETA-OPS tool was used for dimensioning and monitoring OPS installations.