The assumption that Europeans can just absorb high energy prices is crazy. Ought to be a national imperative to invest in infrastructure to lower prices.
Investment won't help there in any way, because if that investment were worth it, it would already happen because of market forces. If it doesn't happen on its own, then the state (doesn't matter which level) has to do it, which means using tax money, which means that prices will rise. So that state investment will further skew the market equilibrium, putting the EU further behind.
This is very much a market-based solution. What the state has to do is provide permits and stuff for getting the batteries etc. actually built; which the state is doing but not as fast as it could right now. (at least in Germany)