One of the problems with a DIY (do-it-yourself) solar panel was removing the solar cells from the outside glass. Have to be really careful to not crack are scuff the wafer thin cells. Solar cells have a blue and gray surface. The blue surface faces the sun. During assembly, tiny dab of silicone should be added to the blue side and then attached to the glass panel. It ensures the strings of solar cells don’t shift around while the encapsulate applied (Slygard 184 or EVA). If the glass gets cracked, bit’s of glass should slide off to the fragile cells. So the choices are: carefully remove the cells from the glass and use a new sun facing glass, fill the cracks with a waterproof expanding sealant, or add another layer of glass. I went with the latter and used a single pane window.
Single pane windows work great for DIY solar panels. They already have the frame and easy to find. Normally find them up for free. I then use aluminium “C” channel on the ends to help hold the new window to the old. A banding of some sort also helps. Careful from using metal screws, they can be over tightened and crack the glass. I use a roofing style of screw with the built-in rubber gromets
Note: it will cut down on some of the sunlight and affect the overall wattage. If used in an array, remove it for a group or use a different charge controller.