2 hour power cuts (Loadshedding)

Within common sense, the autoflower plant cares not for the cycle of light and dark, merely what occurs per day... there's a "ceiling" of enery it can use in 1 day relative to various factors. You can hit that ceiling after 12 hours with a powerful light... Probably won't impact yield too much. Might have a slightly lankier plant... just a guess. Simply compensate on days this occurs by leaving it on long later, if you can. Make sure it's still getting it's 18/6 or 20/4 cycle each day, even if broken up. Probably the single biggest factor is light provided, so that's the primary concern.

Those random 2 hour periods of darkness won't be a problem. Do not bother with battery powered lights. They do not emit a useful amount of light so operating them is waste of batteries. Consider changing your light schedule. Most/all plants benefit from a rest period and most advise running lights for 16-20 hours a day with autoflowers, not 24 hours.