Reducing energy loss in electricity production,transmission and consumptionTraditional electricity system:over90%energy is lost to wasteenergy (e.g., heat).➢How can we improve energyefficiency?
Components of electricity supply industry(i) Generation:operates in large power plants; spare capacity required.(ii) Transmission:high voltage long-distance operation; national network.(iii) Distribution:low voltage regional/city operation; local network.(iv) Sales:monitor, record and bill electricity consumption.
Electricity transmission & distribution networkVoltage stepped down through substations using transformers
Transmission structuresthree-phase “live” wires500,000230,000138,00069,0007–13,000long-distanceneighborhoodto house
•What makes the transformer so valuable is the fact that thenumber of loops of wire in the primary and secondary can bedifferent, and the result is that the voltage and current in thetwo coils will be different.NABVtt==ppssVNVN=Transformers to step up or down voltage (I)applies to onlyalternating current
Transformers to step up or down voltage (II)𝑃 = 𝑉𝑝𝐼𝑝= 𝑉𝑠𝐼𝑠(conservation of energy)𝑉𝑝𝑉𝑠=𝑁𝑝𝑁𝑠→𝐼𝑝𝐼𝑠=𝑁𝑠𝑁𝑝→𝑉𝑝𝑉𝑠=𝐼𝑠𝐼𝑝