When you can’t sleep, what do you think about? Last night I was thinking about power transmission over power lines and why power is transmitted at high voltage.
Here’s the background. Equation 1: P = VI (Power = Voltage * Current). Equation 2: V = IR (Voltage = Current * Resistance) which means Equation 3: P = IIR (Power = Current * Current * Resistance)
Resistance of the power line is fixed so the two variables are Voltage and Current. Looking at equation 1, if either V or I increase in the power line, power (which I’m pretty sure in this case is power loss) increases linearly with respect to the variable.
However, looking at equation 3 we can see that given the fixed resistance of the power line, the power increases by a square power of the current. Given the equations at hand, it makes sense that for a fixed power output, if you have a really high voltage, you have a really low current. Given that current*current is the determining factor in power loss, the lower you can make the current the better.
Therefore, powerlines always transmit power at high voltage to reduce the loss on the line.
Anyone got any better ideas?
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