Emission-free dredging: consequences for implementation and logistics

In recent years, Verboon Maasland has invested a great deal in electric equipment to enable emission-free dredging, among other things. However, the equipment and the entire process surrounding it requires a different way of managing and executing projects, notes operational director Arjan Krijnen. "What we encounter outside is that emission-free equipment is good, but insufficiently developed. That has consequences for execution and logistics."

We see a trend among clients that they are requesting more and more projects to be emission-free, also because it is imposed from the government, says Arjan. "We naturally encourage this transition, but there is more to it than just buying an electric dredger or crane. You also have to work with it and that requires a bit of innovation and understanding, also from clients. Processes have to be organized differently. Electrically driven equipment runs on a battery with often a limited range, in addition, in most cases it takes longer to recharge electric equipment than it does to refuel with fossil fuel. As a result, better thought must be given to the planning of operations. Batteries are good, but by no means always achieve the running hours promised by the manufacturer. Ideally, you would like to have a power point everywhere. That means driving back and forth with battery containers charged elsewhere with renewable power. So there's also a logistical process involved in just powering the dredging equipment. And that's not to mention emission-free disposal of the dredged material. That too requires sophisticated logistics, because it must not harm production."

Quest

Recently, Verboon Maasland has been working on a large emission-free dredging project in the outlying area, using a newly purchased electric pusher and an electric HGM, among other things. "It is running well so far, but not yet as efficiently as we would like," Arjan acknowledges. "Again, we have to drive back and forth with battery containers to recharge the equipment. Sometimes we even have to charge in between, because the batteries don't last all day. The transport of both the battery containers and the dredged material is -unfortunately- still done on diesel, admittedly HVO100 but this is not desirable. In this case, it is an interim solution in the search for the most efficient way to carry out such a project. In addition, this also requires a different way of working for our work preparation/planning." Verboon Maasland is investigating whether a hydrogen generator is a viable option for 'refueling' on site. Apart from this ongoing project, in the fall they will start a pilot for the Rijnland Water Board in which -within a project- they will carry out the dredging completely emission-free with hydrogen as energy source. In full transparency and with an open mind, in cooperation with an engineering firm. 

Arjan says the final step in the process of "sustainable dredging" is to give the dredged material a circular reuse. "Water boards are owners of the dredged material, but not landowners. How wonderful it would be if a synergy could be achieved in this, where the dredged material is not seen as a waste product but as a raw material. All kinds of initiatives are underway in this as well."