I hadn't known about this - thank you!

I followed the link to Sonihul; I’d suggest anyone with questions about how the technology works do the same. All I was unable to determine is the sq m coverage of each transducer.

Also, they mention that each transducer uses "3.6 Watt-hours". I would guess that they mean Watts, as the time component makes no sense.

Still, it looks like a major win for shippers and the ocean. Container ships have bags of electrical generation capacity to run the reefers, and associated air handling devices, so they might not need additional capacity.