Factorio Forums

Looking at the current tech tree, I found a few things that seem odd. Tech requirements that are missing are kinda common, but there are also some extra requirements.

The two that spring to mind are the Armor Crafting 3, which requires speed module tech, and solar panel tech, which requires plastic research.

In both cases, those items have nothing to do with those particular prerequisites. I can totally see solar panels having used Advanced circuits, or maybe plastic, originally, instead of tons of green circuits and copper.

There are probably a bunch more, but I can't think of many.

Solar panels were fixed in 0.13.2.

Huh. Imagine that.

Electric Engines required advanced electronics and plastics to be researched, but don't use it.

Concrete uses the Electric Furnace Tech, but otherwise is unrelated.
Rocket Silo uses T3 Modules for speed and Productivity, but only needs T1 speed modules to build.