Baby steps. Our coaches are all electric when parked. That's a change over past years. If course, it's only a migration from propane to electric which isn't really what you're driving at.

Although the day may come, I struggle with seeing an all battery or even hybrid power being economical for the few miles most RV conversions are driven on annual basis. If CNG availability becomes widespread I suppose I could one day see our coaches becoming CNG/battery hybrid powered using the battery/CNG for house requirements as well.

Although this would be good with respect to carbon footprint, all would not be positive until we can fully migrate away from lead plated batteries.

We still need 500HP to move these big coaches, so an electric motor of this size, enough batteries to serve the power storage needs, and enough generator power may be substantial.

Never is a long way off, so I won't suggest this will never happen. My guess it could be 10+ years away unless hydrogen power or yet to be tapped energy option comes to market. Of course there's always the Tesla and tend option ;-)