We Choose To Adopt Energy Transition, But How Will We Succeed?

President John F. Kennedy speaking at Rice University on September 12, 1962 (Credit: NASA)
President John F. Kennedy speaking at Rice University on September 12, 1962 (Credit: NASA)

‘We choose to go to the moon.’ Was the famous speech at Rice University of President John F. Kennedy to express his ambition to send his nation to the Moon1. At the time, his call was far from clearly achievable. But it was a very clear roadmap and it quickly gained traction. The success of the Apollo project is well known. Neil Armstrong did land on the Moon within a decade and the American flag is still planted on its surface.

Panel discussion at the CEDA Dredging Days 2019 with Mike van der Vijver
Panel discussion at the CEDA Dredging Days 2019 with Mike van der Vijver

At the CEDA Dredging Days 20192, there was an interesting panel discussion on ‘Energy transition: the views in our dredging community’3. Panel members were: Eric de Deckere, Michael Deruyk, Kaj Portin and Klaas Visser. The discussion was moderated by Mike van der Vijver from MindMeeting. As an introductory teaser to the audience, he posited the claim: ‘Excessive ambition drives breakthroughs’. The question is: ‘Is the dredging industry ambitious enough to convert to a new fossil free energy source?’ The audience was polled for their opinion on a scale from one to ten and the response ranged from three to eight. The three represented the position, that the industry is not doing much. What is visibly done, are only single purpose, company specific solutions that are not adopted by the community. On the other hand, there was also a very positive signal with an eight for ambition. The sense of urgency is very well present in the community. Most companies are developing plans and cooperating in working groups, such as the CEDA Working Group on Energy Efficiency4. Also, the government is pitching in with initiatives on zero emission maintenance dredging, where the dredging community is actively participating in putting forward proposals.

So, why is there still no zero emission dredge? What is the ambition lacking? The hint is the opinion that the effort is not focussed. The strong motivation in Kennedy’s speech was that there was a very clear picture what to do. What do we do: ‘Put a man on the Moon’. When: ‘By the end of the decade’. How: ‘Bring him safely back’. Ambition with a clear plan can indeed achieve great things. Ambition without motivation will only bring daydreaming and lethargy.

Block diagram of influencers for energy transition in the dredging community
Block diagram of influencers for energy transition in the dredging community

To achieve something, we need motivation. And who is responsible for pulling this off? Mike polled the audience again for: 1) Government, 2) Public opinion, 3) Companies, 4) Technology. There was not a clear picture here either. All positions are valid. Another driver is the reward for the effort. The Apollo project effectively created part of our modern society. What would the energy transition yield for the dredging community: ‘Learning by challenge’, ‘Flexibility and resilience in energy generation’, ‘Low maintenance and higher independence’?

At this website I can’t change the world, but addressing most issues mentioned, I can only put forward my idea on the ‘How’ motivation. We know how to apply power. As long as the power arrives electrically, we can use it. Essentially, we have to generate electricity with a flexible power source. The investment lifetime of a dredge often exceeds 30 years, but under the current circumstances, the power plant only lasts ten. The solution would be to have some separate module for power generation. Either locally, near the dredge, or remote at the end of the pipeline. As every project and application will be different, it will be a challenge to design the specific solution. But I am looking forward in developing the solutions below with any interested customer5.

Transition schedule to convert to fossil fuel free dredging equipment
Transition schedule to convert to fossil fuel free dredging equipment

References

  1. We choose to go to the Moon, Wikipedia
  2. CEDA Dredging Days 2019, CEDA
  3. Programme 7 November 2019, Panel Discussion, CEDA
  4. CEDA Working Group on Energy Efficiency, CEDA
  5. Innovation at Damen Dredging Equipment, Damen

See also

My WODCON 2019 Presentation: Launching Robotic Dredging

Me, presenting my WODCON 2019 contribution.
Me, presenting my WODCON 2019 contribution.

Yesterday, I gave my presentation at the WODCON 2019 in Shanghai1. The WODCON is the triannual world dredging conference, were everybody in the dredging industry meets and exchanges knowledge and ideas. Just as I mentioned in my New Year’s post, I sometimes like to delve into some old archives, get inspiration and hatch new ideas2. So did I for this presentation.

Overview of the ‘Ketelmeer’ (Credit: Google Maps).
Overview of the ‘Ketelmeer’ (Credit: Google Maps).

A seminal dredging project concerning environmental dredging is the ‘Ketelmeer’ clean up dredging project, resulting in the creation of the contaminated sediment storage depot in the artificial island ‘IJsseloog’3. As careful removal of the contaminated sediment required novel dredging techniques, the government challenged the dredging industry to test four innovative concepts. The results were evaluated by the institute now called ‘Deltares’ and published in a report4. The original conclusion of the report was, that the auger dredge was the best in reducing the turbidity. Later, the bigger auger dredge ‘HAM291’ was constructed and used to actually clean up the lake. With the knowledge and the experience of the auger we also developed a range of auger attachments for our DOP pumps5.

Traditional auger attachment for a DOP pump excavator combination.
Traditional auger attachment for a DOP pump excavator combination.

Reading the Ketelmeer report again, it occurred to me, that one parameter had not been properly accounted for: the size of the dredge. The auger dredge was by far the smallest dredge in the game. With a weighed scoring method, the dredges were also compared in size and installed power. The reasoning is that a bigger dredge has more interaction with its environment. Naturally, the environment gets more disturbed and turbidity levels should be higher for a bigger dredge. And the data was there to support this hypothesis. Smaller is better! Still, this does not undermine the initial results of the concept, as that was evaluated for turbidity per cubic meter. The bigger dredges also delivered more production. But when comparing dredges of the same concept might the smaller ones will perform better on turbidity. And this is in accordance with our experience. Every project where we’ve supplied these auger dredge units, the contractor and the client where surprised and happy about the achieved turbidity levels. Now, we know why: smaller is less turbidity.

The next step in performance might be reached by further decreasing the size of the dredge. However, the DOP is already as small as it is for a viable application on an excavator. The conclusion is to have an auger operating directly on the bottom: an unmanned submarine dredging machine!

Possible general arrangement of a robotic dredge submarine.
Possible general arrangement of a robotic dredge submarine.

This machine should navigate by itself and self-supporting. The wear parts of the auger should be exchanged by itself and solar panels can provide extra energy for extended missions. It has only a small hopper and discharge should also be done quick and automatically. An unmanned barge or even a dump truck trailer at the shore of the waterway can be replaced at longer intervals. Obstacles and other tricky spots can be alerted to a human supervisor for later intervention. One machine alone does not have an impressive production. The real power is in applying them in numbers. As we are standing on the brink of a revolution in robotics and artificial intelligence, this scenario may be not as farfetched as from your first impression. Imagine a whole school of these mechanical fishes cleaning up your waterway, while you sleep…

Working method of robotic dredge submarine (Credit: Judith Korver).
Working method of robotic dredge submarine (Credit: Judith Korver).

References

  1. WODCON, Damen
  2. New Year’s post 2019, Discover Dredging
  3. Ketelmeer project, Wikipedia
  4. Rapportage baggerproeven Ketelmeer. RIZA Rapport, 97.023, ISBN 9036950708
  5. DOP Pumps, Damen

See also

HYDRO 2018 Gdansk: Selecting A Dredge For Your Reservoir Maintenance

Barrage du Ksob, M’Sila, Algeria with a DOP dredge 350

This week, I am here in Gdansk for a presentation on the HYDRO 2018 Conference1 and assist at the Damen booth at the corresponding exhibition. The paper and the presentation are already prepared and I am very excited to do the presentation, but I can’t wait till tomorrow and I like to share the story now, already. So, you, as my favourite audience, will have my personal spoiler after so many teasers have been floating around2,3,4.

General modes of siltation at the usual location in a reservoir

The thing is, dam maintenance and reservoir restoration is something already long on my attention list. Back already in 2008, I wrote a paper on this subject for the CEDA Dredging Days5. Over and over we’ve conveyed the message on various platforms, that dredging might be a viable solution for sedimentation problems in reservoirs. Usually, the solution by dam owners and operators is to flush, sluice or store the sediment. This looks horrible from a dredging perspective, but it is also to the environment. You either smother or starve the downstream river with sediment. As a right minded dredge enthusiast, you see many possibilities to dredge such a project. Immediately we can identify what dredge to use on which location for which purpose.

Selection of applicable dredges for reservoir dredging

If you are very close to the dam and the length of the discharge line allows it, you might even not need a dredge pump. (No wear parts!) It is a so called siphon dredge. But as soon as there is some further transport involved, either distance or uphill, you need a dredge like a cutter suction dredge or a DOP dredge. For even further discharge, you might employ a booster for increased discharge pressure. If the distance becomes very far, you might have to resort to grabs and barges.

Water injection dredging principle and example (this example would be too big for a common reservoir)

As an intermediate solution you might even consider using a water injection dredge. Usually the reservoir is in the mountains and a bottom gradient will be present, enabling the required gravity flow. The actual dredge should have created a silt trap where it can collect the inflowing material from the water injection dredge. Than it can handle the material as usual.

Alternative uses for the dredged sediment a) silt farming as fertile additive b) gravel extraction for concrete

Off course, the dredged sediment belongs to the river and the best thing would be to gradually release the sediment after the dam. But there might be conditions, where it is beneficial to extract the valuable fraction of the sediment and use it for agriculture or as aggregate in the construction industry.

Dredge selection diagram for reservoirs

We noticed, that it is often difficult to convey to dam owners and operators which dredge to select for which job. Sediment is seen as a liability and not as an asset and they rather neglect issues associated with the sediment. So, I made an attempt to have a plain and simple selection diagram. That is the core of my manuscript. But my objective is, that we will see many beautiful dredges contributing to a sustainable and viable operation of hydropower dams and reservoirs.

New DOP dredge family

References

  1. HYDRO 2018: Progress through partnerships, Hydropower and Dams
  2. LinkedIn Teaser, Saskia den Herder
  3. Damen: Spotlight on Hydro Power Dam Maintenance
  4. LinkedIn Teaser, Olivier Marcus
  5. Multi Functional Small Dredging Solution For Maintenance Of Deep Irrigation Reservoirs And Hydro Power Dams, CEDA

See also