Chapter 31, Problem 31.1DQ

Household electric power in most of western Europe is supplied at 240 V, rather than the 120 V that is standard in the United States and Canada. What are the advantages and disadvantages of each system?

To determine

The advantages and disadvantages of the Western Europe power supply system with $240\text{V}$ and United States, Canada power supply system with $120\text{V}$.

Answer to Problem 31.1DQ

Introduction: The High voltage power transmission is an effective transmission system, with reduced power losses to transfer the power economically and reliably.

Explanation of Solution

The transmission lines have the major power loss are $I^{2}R$ losses in terms of heat, this losses are proportional to the square of current and resistance of the line. To transmit the same power by increasing voltage level and reducing the current level, the power losses can reduce effectively.

$P_{\text{loss}}=I^{2}R$

Consider the same power $\left(P\right)$ transmission with these two given systems.

United States and Canada has the standard supply voltage $120\text{V}$, this is the low voltage and high current transmission line, and therefore the power losses are high, because of high power losses efficiency is reduced. It is uneconomical, non-reliable, and high risk.

Western Europe has the standard supply voltage $240\text{V}$, this is the high voltage  and low current transmission line, and therefore the power losses are very low, due to reduced power losses efficiency will be improved. It is economical, reliable and low risk.

Conclusion: Therefore the Western Europe power supply system has the more advantages than United States supply system and Canada power supply system.