Why is AC cheaper to generate than DC?

  • Context: Undergrad 
  • Thread starter Thread starter R0nin
  • Start date Start date
  • Tags Tags
    Ac Dc
Click For Summary
SUMMARY

Alternating Current (AC) is cheaper to generate than Direct Current (DC) primarily due to the efficiency of AC generator designs and the ability to easily step up and down voltages using transformers. This capability allows high voltage AC power to be transmitted over long distances with minimal losses, making it more suitable for power distribution. While AC motors are simpler and more efficient, they do not inherently generate more energy than DC; the perceived potency is due to higher voltage levels in typical AC sources compared to DC sources like batteries.

PREREQUISITES
  • Understanding of AC and DC current principles
  • Familiarity with electrical generators and transformers
  • Basic knowledge of voltage levels and power distribution
  • Awareness of household electrical systems (110V and 220V)
NEXT STEPS
  • Research the design and operation of AC generators
  • Explore the principles of transformers and voltage conversion
  • Study the efficiency of AC versus DC motors
  • Investigate the safety considerations of high voltage AC transmission
USEFUL FOR

Physics students, electrical engineers, and anyone interested in understanding the fundamentals of electrical power generation and distribution.

R0nin
Messages
1
Reaction score
0
Hey guys! Novice physics scholar here who's studying electronics on his downtime. I have some questions concerning AC and DC. If you guys could answer them (simplistically please, I still have a lot to learn :P) I'd really appreciate it.

I'm reading here that 'AC costs less to generate then DC'. Why is that? If anything, I'd think that DC would be cheaper and easier to use. After all, wouldn't it require MORE energy to constantly alternate the direction of a current, as opposed to simply letting a current run a direct course, as it does in DC?

Now, new question... AC current DOES typically generate MORE energy then DC, right? Since the direction of current is constantly being mixed up, the SAME electrons end up traveling a FARTHER distance. Whereas in DC, because the direction of current is so linear, it would seem as if the electrons reach the opposite battery terminal far more quickly then they would in AC, thus lending a shorter 'current life' to DC then to AC. In other words, if you have a 10 V AC battery and a 10 V DC battery, the AC battery would last far longer then the DC.

Am I correct here? Or am I just not making any sense at all?
 
Physics news on Phys.org
R0nin said:
I'm reading here that 'AC costs less to generate then DC'. Why is that? If anything, I'd think that DC would be cheaper and easier to use. After all, wouldn't it require MORE energy to constantly alternate the direction of a current, as opposed to simply letting a current run a direct course, as it does in DC?
AC costs less to generate because the simplest and most efficient generator designs are AC designs but that is not the primary reason that power companies distribute AC. The primary reason is that AC voltage can be easily stepped up and down using transformers. High voltage power can be transmitted long distances with low losses, but is too dangerous for household use. Using AC makes it easy to step the voltage down to a less dangerous level when it reaches the consumers.

R0nin said:
Now, new question... AC current DOES typically generate MORE energy then DC, right?
No. AC motors are simpler and more efficient for the same reasons that AC generators are simpler and more efficient but AC does not inherently pack more punch.
The AC sources you are familiar with are household circuits that are either 110 or 220 volts. The most common DC sources are batteries that range from 1.5 to 12 volts. The AC sources are more potent but it is because the voltages are higher, not because they are AC. 110 volts DC would be just as potent as 110 volts AC.

R0nin said:
if you have a 10 V AC battery
I don't and neither does anyone else. There is no such thing as an AC battery.
 

Similar threads

  • · Replies 7 ·
Replies
7
Views
2K
  • · Replies 10 ·
Replies
10
Views
2K
  • · Replies 31 ·
2
Replies
31
Views
3K
  • · Replies 10 ·
Replies
10
Views
1K
  • · Replies 47 ·
2
Replies
47
Views
9K
Replies
13
Views
3K
Replies
21
Views
3K
  • · Replies 1 ·
Replies
1
Views
1K
  • · Replies 10 ·
Replies
10
Views
5K
  • · Replies 30 ·
2
Replies
30
Views
3K