Our new electricity provider seems to be less reliable than the old government utility, so our computing facilities are run off a bank of lead acid batteries with solar recharge.
The original battery charger was a commercial 2 amp charger, which could charge the batteries in a couple of days. I built a much more powerful charger that could deliver 100A of charge current from the mains. It was working quite well, until I replaced the output inductor with one with greater ringing. This blew the entire output stage from the over voltage and I have reverted to the old system until I can be bothered fixing it.
The current solar capacity is about 6W, which is not enough to charge the batteries, but can maintain them at full charge indefinetely while providing power to the monitoring circuitry. There is a government scheme to set up solar systems, but currently we have decided to leave it alone until we are sure we have enough roof space.