Around six years ago, the media went slightly crazy when a fresh-faced 17-year-old Dutch engineering student, Boyan Slat, claimed to have designed a means for using currents to clean plastic from the oceans. He was covered in the major press outlets, was interviewed on television, and gave TED talks. Despite all the enthusiasm, the unanswered question was, would the design work? So far, the results are not promising.

Remarkably, Slat and his non-profit Ocean Cleanup succeeded in raising $20 million to fabricate and deploy a 600-meter-long prototype boom designed to trap and collect plastic refuse. Their goal was to trap up to 68 metric tonnes of plastic during the boom’s first year at sea. If successful, Ocean Cleanup claimed that a full-scale system roll-out of their design could clean up 50% of the Great Pacific Garbage Patch in 5 years.

The problem, at least so far, is that the boom isn’t catching any plastic. Boyan Slat said the speed of the solar-powered barrier isn’t allowing it to hold on to the plastic it catches.

“Sometimes the system actually moves slightly slower than the plastic, which of course you don’t want because then you have a chance of losing the plastic again,” Slat said in an interview with The Associated Press.

A crew of engineers will reach the U-shaped boom Tuesday and will work for the next few weeks to widen its span so that it catches more wind and waves to help it go faster, he said.

“We’ve given ourselves a year after launch to get this thing working,” Slat said.

Thanks to Dexter Donham for contributing to this post.