The Ocean Cleanup Isn’t Capturing Plastic, But Organizers Are Testing A Solution
20 December, 2018 / Articles
Three months in, an ambitious project to clean up the Great Pacific Garbage Patch isn’t capturing tons of plastic as planned. But that’s why they call it a beta, organizers say. A System 001 left California in September and reached its target in mid-October, with an overall goal of cleaning up half of the massive patch in five years and a 90% reduction by 2040.
Sure, organizers are disappointed that the system isn’t performing as models predicted. But they’re but not deterred, says Lonneke Holierhoek, chief operating officer at The Ocean Cleanup.
A solution is being tested by engineering and technology teams, who hope to launch a System 002 in early 2020, ushering in plans to deploy an improved fleet of 60 units that can get the job done.
“We do not expect it will (affect the 90% by 2040 goal),” Holierhoek said. “If the cause of the problem we identified and the solution we have produced are correct, there will be no significant delay as we allowed for float in our schedule, exactly for this purpose …”
The problem
System 001 consists of a 600-meter (almost 2,000-foot) long floater, with a 3-meter (10-foot) deep skirt attached below. The floater is designed to prevent plastics from flowing over the system, while the skirt stops smaller particles from escaping underneath. The setup takes advantage of natural oceanic forces to catch and concentrate the plastic.
But apart from 2 metric tons of discarded “ghost nets,” no significant amount of plastic has been extracted from System 001 yet, group leaders say. Plastic enters the system, but is only retained for a few days, which is not long enough to harvest it and keep going. This problem came to light in mid-November, and The Ocean Cleanup’s engineering and technology teams have been working to identify the cause and a solution.
“The most-likely reason is that the system is not moving quickly enough at every occurring condition,” Holierhoek says. “It needs to move faster than the plastic at all times so as to retain all plastic it’s caught.”
The skirt is meant to create a downward flow to allow marine life to safely pass underneath it. “It is great that no negative impact on sea life has been observed so far,” she said. “And this is of course also a prerequisite for what we consider a successful design.”
You can follow movement of the system here. It’s traveled about 400 nautical miles in the past month and a half, but not in a straight line, of course. System speed varies with weather conditions. Ideally, the system should travel at 0.1-0.2 meters per second (or almost a half a mile per hour).
How they plan to fix it
Organizers say the solution is akin to putting a bigger sail on a boat. Increasing the span of System 001 is expected increase the surface that will effectively catch wind and waves, adding force and increasing the floater’s speed. They aim to make it 25% bigger, opening the U-shaped floater about 60-70 meters wider.
The Ocean Cleanup team is said to be working hard to come up with improvements every day. But not all of them can be implemented easily at sea. The floater is being followed by a support vessel.
Teams plan to assess adjustments to System 001 over the next month, and implement a solution to the retention problem as soon as possible.
“Once we have an optimal configuration and have successfully landed the first loads of plastic, we’ll start working on the next system design,” Holierhoek says. “This design will incorporate all learnings from the beta version, and should be optimized even further.
“As we want this new system design to be the blueprint of a whole fleet of systems, we believe we can scale up fast, starting to place more systems in the water in 2020.”
The Ocean Cleanup folks note that although plastic hasn’t been collected, more support has come since the Netherlands-based organization launched System 001 from San Francisco Bay. There was global attention and massive interest in the project, and potential sponsors have come forward to help, at the individual and larger corporate and philanthropic levels.
“Although plastic retention is crucial for the system to work, we have been pleased that all the other variables behaved according to models and planning,” Holierhoek says.
“We have always expected the unexpected and the reason we have decided to put out a beta system so early is to address these kinds of problems. The team has proven to be very resilient and is confident that finding a solution is only a matter of time.”
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