Why does…? #8: Why do power lines use such high voltage?
same power at higher voltage = less current, and line loss = I² × R.
Why do power lines carry hundreds of thousands of volts? ⚡🗼
1️⃣ WIRES WASTE HEAT: every wire has some resistance, so it turns some power into heat. That loss = current² × resistance — twice the current means 4× the heat!
2️⃣ THE TRICK: power = volts × amps. Send the same 100 kW at 10× the voltage and you need only 1/10 of the current — and (1/10)² = 1/100 of the loss. A hundred times less waste!
3️⃣ THE GRID: transformers step it up to about 110,000–765,000 V for the long lines, then step it down for your home: 230 V · 50 Hz (India, UK, Europe) or 120 V · 60 Hz (USA, Canada).
High volts, low current, low loss!
Read the voiceover (transcript)
- Why do power lines use high voltage?
- Every wire wastes some power as heat. And that loss grows with the current squared!
- Ten times the voltage: a tenth of the current. That's a hundred times less loss!
- So lines run at hundreds of thousands of volts. Transformers bring it down for your home.
- High volts, low loss!
- Next: how your TV remote talks! Follow for more!
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