1) I think the harbour is so full of trash that there's always some around? But it also looks like they put in a floating line to direct the trash. I bet they parked the thing in a place where garbage would normally collect/flow.

2) The wheel is normally powered by rainwater (think like an old-timey mill in a creek, but with rain in the buckets). The solar panels power pumps to put water into the buckets on the wheel for when it's not raining. I guess pumping water into the bucket-wheel means you don't need a high-torque motor, compared to turning the wheel directly with an electric motor.

I thought the wheel was powered by the current? When the solar pump is pumping water onto the wheel, how in the hell is that drizzle generating enough work to cycle that huge conveyer? I'm thinking the whole thing is secretly coal powered.

Not just any coal. Clean coal. Really. Clean. Coal. Trump promised this today.

Actually, It's not such a mystery. With a large enough gear ratio, it's a workable solution. Just seemed a little rube goldberg to me. I could see certain advantages over a direct drive motor, although the motor would allow you store power in a battery when the wheel is chugging along from the water current. That'd also give you a signal directly proportional to flow to determine when to power the motor rather than use it as a generator.

Do you hear all the times they say "river" and "Jones Falls"? It is poised where the river empties into the harbor. The trash is in the river and flows into the harbor, this machine basically skims off the floating debris as the current passes. This is how most trash ends up in the ocean, its not people throwing stuff directly into the sea, it is litter on the streets washing into storm drains, which ends up in harbors and beyond.

Oh man I bet he flicks it in the harbor after Mr. Trash Wheel passes be.

Not a totally stupid idea, but ocean-faring versions would likely be much more expensive, and you'd need a system to track them so humans could go out and fix 'em.

Maybe in the transition to a sustainable civilization, that'll be one of the tools we use? If only we would start said transition...