Time travel. It's very expensive to move electricity into the future. Batteries are very cheap when you look at dollars per watt of onboarding/offboarding the o

Time travel. It's very expensive to move electricity into the future. Batteries are very cheap when you look at dollars per watt of onboarding/offboarding the one way time machine, but when you look at it dollars per Wh it does not look as rosy anymore. Still worthwhile for short hops. But for longer trips, you want to look at $/Whh and then batteries are atrociously expensive. Seasons are a thing and time travel is hard, even if it's only one way.