I have not inverted the burden of proof, which is often simplified as "extraordinary claims require extraordinary proof" as the claims are not extraordinary. Multiple studies have concluded that with a well-connected grid, batteries can now be scalable. Equally, there have been studies suggesting the opposite. Since the debate seems reasonably balanced then claiming one side is guilty of 'magical thinking' and failing to provide proof doesn't strengthen your case. I'm actually on the fence about whether batteries will be scalable or not but all my reading suggests it is not the open and shut case you seem to think it is. Given that it appears not to be a simple case of preponderance of evidence one way or another, then citing sources is appropriate.