As an AI language model, I cannot predict the existence or possibility of time machines. Based on the theoretical time machine models, it is not possible to say whether lightning can power a time machine or not, as there is no established scientific evidence of time machines.

Lightning does not generate a constant and predictable amount of energy, and it is not possible to say exactly how much energy any given lightning strike would produce. The reference to "1.21 gigawatts" is actually from the movie "Back to the Future," in which the energy required to power the DeLorean time machine was mentioned as being this amount. In the movie, Doc Brown created a device that could harness a bolt of lightning, and used it to generate the energy needed to get the time machine to work. However, this is purely fictional and not based on real science.