i have a plan to supply electric power supply to a colony of around 250 houses each have a load of approximately : 3 x1.5 ton air conditioners and all the other stuff of household use. voltage required is 400v 3 phase or 240 volt single phase. my question is if some one can please calculate the requirement of load for the above requirement and what size of generator is required for this load. thanks
Here is a sample answer for gasoline generators to run a SINGLE HOUSEHOLD. Multiply the answer by 250 but just remember that diesel costs a lot more money. NorthStar Trifuel Generator — 614cc, 13,000 Surge Watts, 10,500 Rated Watts Fuel consumption is as follows: Gasoline:1.72 gallons per hour @full load. 1 gallon per hour @1/2 load. 1.72 gal @ $5 gal 41 gal $205 per day $1,435 7 days ($0.143 Minute) 1 gal @ $5 gal 24 gal $120 per day $840 7 days
With that large a system, you should get a quote from professionals. You need better numbers on power usage, both average and peak. And the pros can help with that. See if you can get a sample of 10 electric power bills and use that as an average to calculate the average power for all 250. Peak is difficult. They each have 4.5 ton worth AC? must be a hot climate. You can use 1.2 kW per ton, so that is 5.4 kW per house or 1.4 MW total just for the ACs Is there electric stoves, hot water, etc? that could double the above number. So we are up to perhaps 3 MW already. At that level, you probably need a higher voltage system, perhaps a 6 kV distribution system. That costs money, plus all the transformers, one per 2-4 house, plus all the underground digging. Assuming you want this underground, not on poles. Again, contact a company that does this, such as Siemens, Bosch, GE, they would be happy to give you a good quote. edit: when you look at the ratio of peak power to average power, you will see a large number, as high as 10. that means you could require a (eg) 3 MW generator although the average power is only 0.3 MW. That means the efficiency is low and the costa are high. That is why large power distribution systems are much better, as the peaks are not nearly as high, and also power companies have special units that are usually offline and come online to handle the peaks.
