whats the capacity of generator that can power 42 2hp air conditioners?

Answer 1

well, each hp is approx 746 watts. so 42 * 2 = 84
then 84 * 746 = 62,664 watts

Answer 2

Actually you are going to need to get the full load amp rating off of the air conditioners nameplate, then if you are sure that all of them will be running at the same time you will have to multiply that by 42. Generally when sizing power for compressors you would need to multiply the total by 125 percent but I do not think that would be necessary in this case because I doubt that they would all be starting and cycling at the same time. It is going to be a very large generator either way, probably a little under 100,000 watts.