If we had the ability to detect neutrinos in such a small volume as a solar panel they’d be immensely valuable for communication - we’d be able to beam signals directly through the Earth, or through deep water.
Following that same line, if we had that ability, it would be useful for communicating to deep submarines like the U.S. used to do with Project Sanguine[0] and ELF waves :)
[0] https://en.wikipedia.org/wiki/Project_Sanguine