Supply Side Efficiency
Increasing efficiency within energy conversion to electricity has to be carried out at the stages of Generation, Transmission and Distribution.
Here, the overall efficiency for the coal based power plants ranges from 28% to 35% depending upon the size, operational practices and capacity utilization. After generation at the plant, electricity is transmitted and distributed over a huge network. The basic function of transmission and distribution equipment is to transfer power economically and efficiently from one location to another. Conductors in the form of wires and cables strung on towers and poles carry the high voltage and current. Energy loss in transmission lines occurs in the form of heat losses.
The power transmission and distribution system has several other components such as capacitors, circuit breakers, switches, relays, and fuses. Transformers are placed at strategic locations throughout the system to minimize power losses within the T&D system. They are used to modify the voltage level from low to high in step-up transformers and high to low in step-down units.
You might like to know what the energy efficiency is as electricity is transmitted from the power source to the end user. It is 87%. Therefore, the technical losses are of the order of only 13%. Here, the standard technical losses are around 17%, which implies an efficiency of 83%. Therefore, in the case of industrial users the whole energy efficiency is 50%. This is since at the user's premises, there is a network of transformers, sub-stations, motors, pumps, flow control valves/throttling etc. that further reduce the energy efficiency. So a change in efficiency at each stage of power is transmission from a thermal plant to the user. The efficiency of the T&D system from the output of the power plant to the end use is the product of all efficiencies (except the generation efficiency) given in the figure.
If you want to go into the technical aspects of supply side energy efficiency, you may like to read the information given in the box below. You may skip it if you are not technically inclined.