Why is electricity generated as alternating current and not as DC?
2 Answers
This is not true
Explanation:
We have both AC and DC generators which generate AC and DC current , both run with same mechanism but differ by just , that DC generator uses split rings but ac uses slip rings . for more details you can see a proper demonstration on YouTube .
The main reason is that the voltage of Alternating Current can be "stepped up" for long distance distribution and then "stepped down" for local distribution, using transformers.
Explanation:
I believe that you are asking; "Why is Alternating Current commonly used by Electric Companies to provide electric energy to their customers?"
Here is an example:
Let's assume that you are a power company and you have chosen to use DC:
1 mega-Watt industrial load (
10 kilometers away from the power generator and the resistance of the power lines are
The loss of the power by the 2 power lines (one for + and the other for the -) is:
The voltage drop on the power 2 power lines
This means that your generator voltage is
Consider the same problem with AC and you can step-up to 250,000 volts for distribution and step-down at the load:
1 mega-Watt industrial load (
We step up the voltage to 250,000 volts for distribution:
10 kilometers away from the power generator and the resistance of the power lines are
The loss of the power by the 2 power lines (one for + and the other for the -) is:
The choice between losing 10 million Watts to deliver 1 million Watts or losing 32 Watts to deliver 1 million Watts to a customer is simple. That is why power companies use AC.