Windsun wrote:

... Basically, 100% uptime will cost you a lot more than 99% uptime.

If cloudy days were coinflips, storing enough energy for 1 day would
make 50% uptime possible, 2 would make 75%, with 3 for 88%, 4 for 94%,
5 for 97%, 6 for 98%, and 7 for 99%... 100% would be impossible.

Nick