They gave Curiosity and Perserverance a plutonium power source to avoid this issue. My experience with "why don't they just X" for space stuff is that there's

They gave Curiosity and Perserverance a plutonium power source to avoid this issue. My experience with "why don't they just X" for space stuff is that there's almost always a technical paper on it. This looks like a comprehensive review of different approaches to cleaning solar panels on rovers: "Cleaning Mechanisms for Solar Panels of Rovers and Other Extraterrestrial Unmanned Vehicles" https://doi.org/10.2514/6.2019-3452 https://doi.org/10.2514/6.2019-3452