I've been considering the project enclosure, and I really want to print the case for the ZPC ("Zombie Plop Core") device. I could use a windowed project box like this one from Hammond Manufacturing, but then there'll be all sorts of kludgy hacks to get the boards and components fixed and stable in the right position. However, printing the case precludes having a truly clear window for the solar cell, because clear ABS plastics yellow and turn translucent when printed, significantly reducing the amount of energy to hit the cell. The solar cell could be attached on the outside of the case, but this device is intended to be hardy and long lived - placing a fragile solar cell on the outside of the enclosure doesn't meet that design requirement.

I think I'm going to try to get the best of both worlds - print a case with standoffs on top for the solar cell, and laser cut plexiglass or an equivalent material to affix over the cell (supported by the additional standoffs, not the cell) for impact protection. The case should also have large "ears" on the base that will allow it to be nailed or otherwise attached to a roof or wall with appropriate solar exposure.