Rooftop solar generally requires professional installation. Balcony solar, as discussed in the article, does not require professional installation and simply plugs directly into an outlet.
I do wonder if having an electrician come by after the fact to inspect it counts as "supervising", though.
The exam is much harder than one might expect, but if you're reasonably competent with residential wiring, far from impossible. It covers a bunch of stuff that is irrelevant for 90% of all residental solar installs, naturally.