Hello I have a question about electricity. I know that transmitting power over long distance is better in AC. I also heard that the voltage needs to be high to reduce losses. I wanted to calculate this for myself.
Imagine there is a windmill that produces 100 kW of power. This 100 kW needs to be transported over a 1 km wire that has 1 ohm of resistance. We can transfer this 100 kW of power at 1kV or 10kV. But we are going to look which one is most beneficial.
When we send the 100 kW at 1 kV:
- This means we have 100 A (Power/Voltage) with a loss of 10 kW (Current2*Resistance).
When we send the 100 kW at 10 kV:
- This means we have 10 A (Power/voltage) with a loss of 0.1 kW (Current2*Resistance).
This proves that the losses are less when the voltage is high than when the voltage is low. However I noticed something odd. When we send the 100 kW at 1 kV I calculated that the current is 100 A via the power equation (100 000 / 1 000). But when I calculate the current via ohm's law I get 1 kA (1 000 * 1). What am I doing wrong?
EDIT: found it, can't use ohms law because not the full 1000 Volts is used on the transmission wire.