Storage is important to protect yourself. California had rolling brownouts and blackouts a couple years ago because of power issues.

I do think you should feed back the grid when you can and most systems do this. However if the grid goes down, your solar/wind/etc. system shuts down. The reason is that it can't "energize" the grid as that's a danger to a lineman looking to repair something. So you need some sort of of short term storage.

Out here we have a generator, so now the grid-connected systems start to make sense. Most people might not need a generator and would go with $2-3k in batteries instead of $5-10k for a generator.