The four repeaters in my area are run by one club. They do the Field Day exercise every year and from what I remember they run them around 150w per repeater. A small jenny could run those fuckers on 15gal a day fairly easily. In a huge emergency, though, you can relay morse on just 5w through 5 or less relaying techs to most of the world without repeaters at all. (1 if you’re lucky, but I’m being fair to real life interference).