Why is it economical to use high voltages for the transmission of electrical power?

Answer 1

Followings are few reasons.

1. At high voltage for the same power, value of current will be less.

2.If less current in line then less transmission loss(IR2) will occur,which will again save money.

3.If the current will be less then less size of conductor will be required and will save money.

4.If less size then less weight and less strength of poles will be required which will again save money.

I hope will these reasons you can understand the fact.

Answer 2

All transmission lines have resistance and therefore there is a voltage drop proportional to the length of the lines. Therefore you have to start with higher voltages to get usable voltages at the receiving end.

By using high voltage it its possible to send more power (wattage) with less

loss because W=V x A. There is a loss of voltage but that's not the primary reason.

Further Answer

The above answer is misleading, as using high-voltage transmission lines has nothing directly to do with compensating for voltage drop along the line. That is controlled using Transformers.

For any given load, the higher the voltage, the lower the resulting load current: i.e. I = P/V

Lower load currents are required to prevent excessively-high voltage drops from occurring along the length of the conductor.

Lower load currents also mean conductors with lower cross-sectional areas may be used. If lower voltages were to be used, then the resulting high load currents would require large cross-sectional areas resulting in conductors that are far too heavy to support (not to mention expensive!). The secondary reason is that lower load currents mean lower line (I2R) losses due to heat transfer away from the conductors.

Answer 3

High voltages are used due to the electrical definition of power: Power = Voltage * Current, or Current squared times resistance. Since resistance is an inherent characteristic of the wire used, as the power sent through the power line increases, so does the losses in the power line (the power line will heat up based on how much current is passing through it). This means for every kW of energy you need in your home, the power company has to create x kW more that is used up in the power line.

If the voltage is increased, then the current must decrease for the same amount of power (first equation), so the losses in the power line will also decrease.

Another Answer

The primary reason for using high voltage is to reduce the load current, so that the voltage drop along the length of the line is minimised. Line losses are a secondary reason.

Answer 4

In power transmission system, the distance of transmission does matter. The further distance, the more power loss will occurs. The is two main element in power transmission which is current (I) and voltage (V). The power loss can be minimized by reducing the amount of current in transmission. P=IV. So, increasing the voltage will cause the current will decreasing the current hence reducing the power loss.

Answer 5

For a given load, the higher the supply voltage, the lower the resulting load current. If we didn't transmit electrical energy at very high voltages, the resulting line current would

• require impractically-large conductors in terms of their cross-sectional area and weight.
• cause a huge voltage drop along the line.
• cause huge line losses .

Answer 6

Since power is the product of voltage and current, for a given load, the higher the supply voltage, the lower the load current. Reducing the current ensures (a) minimum voltage drop along the line, (b) minimum line losses, and (c) conductors of practical cross-sectional areas.

Answer 7

For the same power, higher voltage will have less current and less energy loss.

P=E*I, E goes up and I goes down for the same power.