Can you raise the limit on the tech tree or add more stuff to it because the late game you have billions of science and the only thing you can use them on is the UT attack upgrade.
If you want the solar panels to be worth it, you have to get them in a class O solar system where the luminosity is about 150,000. The enemy's are sufficiently harder in there though.
I buffed them enormously in v1.31 which I'll upload right now. Sadly green stars already initialized won't be buffed. :(