Fishing vessels, notably the large North Sea trawlers that fish for plaice and sole, gasoline guzzlers. One way to curb their fuel consumption – both for financial and energy transition/climate reasons – is to use alternative energy sources. This report, which was commissioned by InnovationNetwork, explores the opportunities for generating various forms of energy on board. The result is a number of promising options that could be developed further. Clearly, there are other options for reducing fuel consumption, such as alternative fishing techniques, but these were not examined in this report.
Until the advent of steamships and motorized vessels, wind was the main source of energy in the fishing industry. Modern fishing techniques, however, rely on the greater power generated by the engines of today, so a straightforward return to traditional sailing ships is not possible.
Besides traditional sails, other techniques for harvesting wind energy include the kite, the Flettner rotor and the wind turbine. The kite appears to be the most promising option in the mid-term, while sails too may prove viable. In the longer term the Flettner rotor may also become interesting. Kites and Flettner rotors can probably be fitted with only minimal modifications to the ship’s design. All three options can in principle make a significant contribution to the propulsion of the vessel.
Solar energy can be harnessed with solar panels. This is an already known technology that is still undergoing further development. It is applied on a very small scale on ships. Given the currently high costs and low potential, this technology does not seem immediately suitable. Another solar energy option is Concentrated Solar Power, where mirrors are used to concentrate sunlight. However, the constant motion of the ship rules out the on-board application of this technology at the present moment.
Energy can also be extracted from water, e.g. from tides and waves17(*). Existing ideas for harnessing the movement of water on board are still in their infancy. These are long-term options and further research is necessary to quantify their potential and develop the technologies.
Other energy sources
Two technologies that come under none of the above headings involve generating energy from gravity and from water discharges. The gravity option involves storing the energy released when nets are lowered; with the water discharge option, small turbines are placed in the conduits for discharging water. The potential of both technologies is limited, but they
have the advantage of only requiring minor modifications on board the fishing vessels.
Which options are recommended?
All technologies were tested against two criteria:
1. Can they generate a significant amount of energy?
2. Are they practicable solutions for application on board beam trawlers?
In addition, we looked at the time scale within which the technologies
could be made available to the fishing industry. Some of the technologies
are immediately available, some are still being developed, and some are still
in their infancy.
We conclude that the following options could lead to significant fuel savings
and thus help to achieve InnovationNetwork’s objective:
- Sail (medium to long term).
- Kite (medium term).
- Flettner rotor (long term).
The kite probably offers the best opportunities in the medium term, so the
advice is to explore this option further and to see whether a pilot project can
be carried out. The two other alternatives, notably sail, also seem promising
in the longer term and merit further research.
The following options probably have a fairly limited potential, but the
uncertainties over their potential and practicability are still substantial:
- Energy from water movement (long term).
- Energy from vessel movement (long term).
(*) Another technology for generating energy from sea water is to make use of differences in temperature between deep and surface water. However, the differences in temperature in the North Sea are too small for this.