Never put too much trust in your computer, or in society. You never know when either one might crash.
— Sean Kennedy, TFM
Ever tried viewing self-imposed blackouts (Earth Hour-style) as an exercise in seeing how you'd do without electricity?
Earth Hour is one hour. Try it a few times a year. Try once per month.
Then try a day at a time.
You may have to, sooner than you'd like; the Powers That Be would like nothing more than to rake in some extra cash, by way of upping the price of something they control by (de facto) monopoly. While telling you there's a shortage or something. (And "forgetting" that the "shortage" is cos they've deliberately elected to not make more.)
As such, Earth Hour would be an exercise in getting by without their control over you.
Failing that, get your own generator, your own solar panel, your own UPS. That way, next time they try a blackout, you can flip them the bird...