Calculate the cost of energy lost

Question

You should establish a power plant that needs 30 MW of power. 220V - will consist of a two-wire line of copper wire with a diameter of 0.5 mm. Calculate the cost of energy lost to heat per hour, per metre. Cost $0.15 per kW hour

Answer 1

Please, check given diameter of the wire.

It cannot be 0.5 mm, as it that case the wire would melt (P=30*10^6 W) instantly.

In any way, you need to calculate loss of energy P_lost= IR where I is current flows through the wire and R is resistance; R=ρL/A where L length of the wire and A is area of the wire.

To find the current you need use equation P=UI where P is power, I current, U voltage.