If the inevitable fate of all Mars landers is to succumb to power failure caused by mere dust, why is it still standard practice to rely on wind? Why not equip the solar panels with windshield wipers?
It comes down to, "What percentage of energy output from the panels needs to be devoted to keeping them clean?" If it's 100% there's no point in going to Mars, if it's 0% there's no point in using solar panels.
At least back with Opportunity the solar panels did have wipers. They ended up lasting much longer than expected. I'm not sure whether Insight has wipers or not, but it's possible they shifted too far in the other direction.
I would have expected the answer to be "a tiny fraction, that will immediately pay for itself". We're talking about a rover equipped equipped with heaters so it doesn't freeze overnight. A couple of Joules to swish a soft brush across the panel every week seems like a good investment.
