I am looking into this myself. Based on the article, I would reiterate the importance of knowing your local laws and ordinances and even your HOA policy (if any) on batteries and solar.

My general stance is you should have a wide degree of freedom with what you build and do on your own property.

However I’d say any significant electrical work you do, you should pull a permit. This gets a extra set of eyes on the work (when it is inspected). It also gives you protection for insurance purposes. If your house burns down at some point, you don’t want to be in a position where you are telling the insurance company that you did a bunch of unlicensed and unpermitted electrical work.