Contrary To Popular Belief, KPLC Does Not Sell Electricity!

By MUNGAI KIHANYA

The Sunday Nation

Nairobi,

21 August 2005

Charles Marwa is a bit confused about electricity; especially by the different figures used. Says he: “I buy a bulb that is 100 watts, my speakers are also rated in watts, my mains are 240 volts, 50 cycles (or something), my fuses are rated in Amps, then am charged by KPLC in watts per hour? What is a power, current, voltage etc and how are they related to each other, I must confess I am a bit confused.”

Electricity is the flow of electric charge, thus an easy way to understand these figures is to think of water flowing in a pipe. Suppose the pipe is connected to tank kept above the ground. The height of the tank would correspond to the voltage in electricity.

The speed at which the water flows in litres per second (or, strictly speaking, kilograms per second) would be equivalent to the electric current. In the case of electricity, the current is measured in Amperes (or “Amps” in short) and one Amp simply means one unit of charge flows through the wire every second.

The rate at which this flow transmits energy is the power; measured in watts (W). In the case of water, the total energy transferred to the ground would be weight multiplied by the height from where it is flowing. It is the same with electricity – power is equal to voltage times current.

The electricity we get from KPLC does not flow continuously from the generators to our houses. It makes a cyclic to-and-fro movement 50 times every second – that’s the 50 cycles stated on appliances, sometimes written as50Hz. That being the case, can we then take the electricity company to court for charging for something that they give and take all the time?

Imagine if the water company did the same – one moment they pumped the water to your house, the next sucked it out back to their reservoir. If they did this 50 times per second, would you have received any water by the end of the month? No. Would they then be justified to bill you? Of course not! Why then, is KPLC justified to charge for something they give and take?

The answer is that, contrary to popular belief, KPLC does not sell electricity – it sells the energy transmitted by the electricity. If the water company did the same, they would not charge for the volume consumed but for the energy contained in the flow.

To see the picture better, suppose you connected a small turbine to your kitchen tap and then used it to operate a fan for cooling the room. When the water is open to flow, the fan would rotate. If KPLC was managing the pipeline, they would not charge you for the volume of liquid but the energy used in rotating the fan. In fact, KPLC would have another pipe for returning the water back to their reservoir.

Thus the electricity bill shows consumption of kilowatt-hours (not “watts per hour” as Charles says) consumed instead of “electricity”. The total electricity consumed is obviously zero