A cruise ship needs as much electric energy as a small town with 20,000 inhabitants. This energy is produced by on-board diesel generators which produce significant emissions even in the port. But there is a solution that meets worldwide interest.
The challenge: Less emissions under economic conditions
Even while in the port, a cruise ship generates its own energy and thus pollutes the environment. In Hamburg alone, more than one third of all measured nitrogen oxides are produced in the port, and the 160 cruise ships per year account for a significant proportion of this.
But a ship with an energy requirement of at least 5 MW/h can not simply be connected to the public electricity grid. That would require investments in the tens of millions at least – to provide the required amount of energy, to convert the grid frequency and to build up the security technology.
Ideal would be an energy supply, which ensures that cruise ships can switch off their diesel generators at least while in the port. Such a supply would not only have to be much more environmentally friendly than burning dirty marine diesel. It would also have to be able to guarantee the required supply while being economically competitive.
The solution: Liquid natural gas instead of marine diesel
HPE Hybrid Port Energy is a subsidiary of Becker Marine Systems and was founded to provide solutions for green energy generation in the port. The first product of the company is the LNG Hybrid Barge. It was christened in 2014. Since 2015 it supplies the cruise ship AIDAsol with clean energy during its stay in the port of Hamburg. The barge measures 76×11 m and is equipped with five Caterpillar gas generators. They deliver a total output of 7.5 MW/h and are therefore able to cope with the energy requirements of even larger cruise ships.
The energy source is liquid natural gas (LNG), which is stored in two 15-ton container tanks on the barge. Compared to the relatively noisy diesel engines of a cruise ship, the barge works almost silently. The CO2 emissions are 20% below the aggregates on board a cruise ship. For NOx it is 80% while there are absolutely no emissions of sulfur and soot when burning LNG.
Another advantage of the LNG Hybrid Barge is its mobility. In the summer, her berth is at the cruise terminal (CC1) in Hamburg’s Hafencity, where the AIDAsol is mooring during its Hamburg stays. In winter, it serves as a mobile combined heat and power plant and supplies one of Hamburg’s container ports with heat and electrical energy.
A critical point is the economic aspect. Energy production via on-board diesel generators costs a maximum of 3 cents per kW/h. Electricity from the public grid would not only require significant investment to be refinanced. There are also network charges and the entire burden of taxes and levies. This simply prevents any economic operation.
As the LNG Hybrid Barge is not considered an energy supplier, all these charges are eliminated. The barge does not sell electricity per kW/h, but is simply chartered for the cruise ship’s laytime. The total cost is slightly higher than on-board electricity. However, especially in the cruise sector there is a willingness to accept slightly higher costs in the interests of image and the environment.
The potential: A Hamburg innovation meets with worldwide interest
Providing external power supply of cruise liners during laytime is on the agenda of many ports worldwide. Along the American west coast, every cruise ship is already obliged to use shore power while in the port. In Europe, a similar trend is emerging.
However, not every port is capable of providing enough electrical energy at a reasonable cost. The LNG Hybrid Barge provides a relatively short-term solution. It works independently of existing network structures and ensures a secure energy supply at very low emissions.
HPE Hybrid Port Energy is currently talking to several other ports far beyond Europe. Barcelona is the largest European cruise port and seems to show interest in the solution. In Barcelona as well, the emissions of the numerous cruise ships are considered a serious problem.
On a technical level, the company is already working on the next generation of the LNG Hybrid Barge. The keyword here is TWOship Barge. It describes a similar solution with an electric power of 24 MW, able to supply two cruise ships at the same time with electrical energy.
As of September 2019