I'm not exactly sure what needs a power source here. There's something with wires coming out of it (photos: front, back) at the heart of the cross; perhaps there is (or was) a light there? Here's a closer look at the solar cells.
Day 690
Solar-powered tombstone
November 19th, 2013
Very interesting! For years I’ve had an idea in my head of a solar panel on a tombstone, that would power a pre-recorded message (music, poem, etc.) from the deceased. Visitors could push a button and hear the recording. I’ve never built a prototype, but maybe someday….