I never thought I would say anything positive about a hybrid but here goes. But this isn’t the typical hybrid. This is an electric-assisted trailer to attach to a semi cab.
Basically it is a trailer with a battery and electric motors that senses what the cab is doing and adjusts appropriately. That adjustment can include regenerative breaking which is free energy over normal truck operation plus savings on brakes.
It’s an interesting idea. How practical it is will clearly depend on the use case of the semi but it could be a big benefit in a stop-and-go environment.
See more at https://newatlas.com/automotive/range-energy-electrified-trailer