This summer, many travelers started to see more of a rental car option they never would have considered a few years ago — electric vehicles (EVs). EVs are becoming an option for renters, especially at Hertz — 10% of the car rental company's total fleet is electric. Some people may want to drive an EV they don't own for the first time, but the big question is: Where do you charge them? Several hotels are trying to answer that question with mixed results.