Depends on usage x the rate you will pay.
If you rent, then the unit rate will be anything from 5 bht upwards. If you own your condo then you will pay the basic government rate of around 5 bht p/kw
I pay 7 bht p/kw and we (x2) only use AC to bring the temperature down a few minutes each time, about 10 times a day. I have fans in living room then bedroom on constantly
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while we’re indoors. My electricity bill is around 1300 p/m.