Look at how fast various nations ramped up advanced (for the time) military production before and during WWII, or the Manhattan Project, or the Apollo program, or China's rapid rise.

Engineers who know how to build factories, batteries, and solar panels could sit down and create a "war plan" to build out and scale infrastructure quickly if you asked them to do it and then got out of the way.

The EU has plenty of talent with the know-how to do this. If it couldn't be done even in a crisis situation, that's a political problem.

it’s my understanding that inefficient bureaucracy is the biggest stumbling block for rapid infrastructure or technological growth. engineers can get it done but the bottle neck will likely be to do with how fast government bodies can move

it’s my understanding that inefficient bureaucracy has always been significant stumbling block for infrastructure