What are the prerequisite for the solar panel array research option?

[BigCheese]

The tech itself should be low tier (2500 tubes), but never shows up. I've been running an industry expert for decades, only picking cheap techs as not to bloat tech selection by opening up higher tiers. No luckso far. Am I missing something? At the moment playing Klingon, but getting it took me ages with Federation and Romulans as well.

[DarkestOnion]

The only thing you can do is hope the technology for Additional Research Options is semi-randomly offered. This is a feature likely designed in the interest or having each replay play out in different technological sequencing.