If I invent a solar powered machine, I think battery charger for smartphone will be good. = If I would invent a solar powered machine, it would be a smartphone battery charger. Because solar power can't provide enough electricity for huse thing such as plant and car. =because solar power can't provide sufficient energy to huge electricity-generated things such as plants and cars lso efficiency is not good compared to fossil or nuclear energy. But size of solar powered system is small compared to those systems. It can be developed in portable and flexible.