You don't need to have a competitive advantage to gain from trade. You don't even need a comparative advantage.

You think that trading electricity to the rest of Europe will let them take your manufacturing industry. So your plan is to pointlessly increase Europe's electricity prices by breaking the market mechanisms that allow trade?

That is not a good plan. It's not a good plan if you want to support local industry and it's not a good plan if you don't. It's just not a good plan.

At best, you could claim that there's nothing else you can do that would work, and so this bad plan is better than all the other worse options but frankly it's not a very convincing case.