I understand that the materials and process of manufacturing PV cells is similar to standard computer chips. How hard is it for a standard computer chip fab to output solar PV cells?
A chip fab has one of the same input materials as some PV cells: very high grade silicon wafers. And each will have a super-clean fabrication area, with staff trained to work in such an environment.
But that's about the sum of the similarities: all the tooling, testing, calibration and other materials will be different.
So it would be like asking if a standard car factory could output some bathtubs - they might both have components made from steel sheets, but that's about it.
Also, PV cells are getting pretty cheap now, and new PV fabrication plant can be built very quickly; furthermore, conversion from chip fabrication to PV production could be very expensive, so there's not really any market for it.