I wouldn’t say there are frequent outages. For the year I lived in Grecia, for example, we only had one power outage. It lasted 30 minutes. Some areas, especially rural areas, can get more outages because the power infrastructure isn’t in as good shape. The Caribbean coast has this issue. But even there, outages are not a daily occurrence or anything and usually it’s up and running within a couple of hours at most
That said, there are gas-powered and liquid propane generators available.