Comment Travel trailers too (Score 2) 48
There are a few electric travel trailers out there now. They are fully electric, like these, but I guess when you combine with the hauling vehicle you could call the whole system a hybrid. Besides the usual regenerative braking, you could apply a little resistance on long flat stretches of road to top off the battery for either an upcoming hill, or to run a refrigeration unit. With route planning, the system could know if you have a big hill coming up and need to top off, or if you'll be dropping the trailer before then.