African safari accommodations in general have electricity, but not necessarily in the tent. Usually the rooms in lodges have power sockets in the rooms, but not all tents in tented camps have. Some tented camps, even luxury-tented camps, have power sockets in the lounge area where the guests can recharge their electrical devices. Mostly there are enough sockets to have always access to electricity, but it demands a bit of planning. When you for example want to charge the battery of your camera for the next morning game drive, bring the charger with you for dinner and let it there for the night. It is very interesting how used we are to the power coming out of the wall, everywhere and any time, but when you are in the bush, you realize power needs to be generated and in many camps this still happens with their own generator or solar power.
Check also before you go what adapters you need to recharge your devices. Some lodges and camps provide adapters, but not all.
When you go on African photographic safaris you should be prepared for all this. When you go on mobile safaris it is even useful to have an inverter to recharge while driving.