Lighthouses are primarily powered by mains electricity, with some older models utilizing Radioisotope Thermoelectric Generators (RTGs) in remote locations. Wind and solar energy are potential alternatives, especially since lighthouses are often situated in windy areas, though reliability concerns exist. Backup power sources, such as diesel generators, are commonly used for lighthouses in isolated locations. The discussion highlights the innovative use of RTGs, likening them to mini nuclear power plants for lighting. Overall, lighthouses remain in operation, adapting to modern energy solutions where feasible.