Science · 6 pages · 12 min
Why long power lines run at high voltage
High voltage moves the same power with less current, and less current means less heating in the wire.
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From the opening
Long power lines run at high voltage so a given power can travel as a smaller current. Heating in the wire rises with the square of the current, so lowering the current cuts that loss faster than a small change in the metal would. The opening covers why loss follows current squared, what the step-up is doing, and why the voltage comes back down.
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Inside
- Why loss follows current squared
- What the step-up is doing
- Why the voltage comes back down
- Where direct current is used instead
- Where the idea stops applying
- A distinction worth keeping
Sources
- Resistive loss rising with the square of current
- Step-up and step-down transformers on a long line