SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/elec-hv-transmission

Why do utilities send electricity over long distances at very high voltage?

Higher voltage means smaller line losses.

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  1. High voltage is safer to touch
  2. Transformers only work at high voltage
  3. Power losses in the lines are much smaller ✔

Why: For the same power, higher voltage means less current. Line loss is current squared times resistance, so a small drop in current saves a lot of energy.

Huh, didn't know that: Power plants step voltage up with transformers to 330,000 volts or more for long-distance lines.

The dad joke
With great power comes great current squared times resistance.
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References

Answer: Power losses in the lines are much smaller. For the same power, higher voltage means less current. Line loss is current squared times resistance, so a small drop in current saves a lot of energy.

  1. OpenStax College Physics 2e, 20.5 AC vs DC openstax.org/books/college-physics-2e/pages/20-5-alternating-current-versus-direct-current
    High voltages can be transmitted with much smaller power losses than low voltages.
    Checked 2026-10-10.

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Trades & ShopOne ohm of resistance is defined as one volt for every what?Trades & ShopIn Ohm's law, current through a resistor is directly proportional to what?Trades & ShopIn a series circuit, which quantity is the same through every resistor?

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