Sizing PV for a UPS

[Daox]

I get a monthly or so email from home power magazine. They have a section called 'ask the experts' where they answer letters sent in. This month, they answer this question:

In third-world countries, there is frequently unscheduled load shedding by utilities. In some areas, service is on for one hour and off for two to three hours. As a result, batteries used for uninterruptible power supplies (UPSs) get drained quickly and ruined. I want to install a solar-electric module to fully charge the battery, at least during the daytime hours. Can you tell me how to calculate PV module size to match a battery’s amp-hour capacity?

ASK THE EXPERTS: Sizing PV for a UPS | Home Power Magazine


I figured some of you would be interested.