That sort of maintenance can easily be done without the need for specialised engineers. A gardener can mow the lawn, a janitor can clean the panels, and most solar plants are not on tracks but static.
But that's not what I had in mind. When an inverter fails, it has to be replaced, and meanwhile a few panels don't produce power. A few, as opposed to all. You get many small failures that cause the plant to produce ninety-some per cent of its possible output instead of the nuclear kind, where the plant is down and produces zero energy, and can't be turned back on even with several days of advance warning.