I double-checked and you're entirely right, i didn't know that, i've heard many years ago that a single big lightning strike could power a large city for months(, while it's indeed more a matter of minutes, if not less), and thought that it was a technological problem(, and that, e.g., flying devices anchored on the ground to either a portable infrastructure or a nationwide-extended network, could potentially make up for the unreliability and follow the storms, or even perhaps cause them one day).
Now i understand even better why solar power is preferred, thanks !