Generators cannot to produce more power than what is demanded by consumers!

By MUNGAI KIHANYA

The Sunday Nation

Nairobi,

20 August 2023

One of the common complaints about the electricity supply system in Kenya is that Independent Power Producers (IPPs) are paid to generate more power than what the country needs. The reality is that this is quite simply not true. A generator cannot produce more power than what the consumers are demanding.

Power in an electrical system is determined by multiplying the voltage supplied multiplied by the current drawn. The generator supplies voltage and this allows the consumer to draw current. Thus, when the volts supplied are multiplied by the amperes drawn, we get the power – supplied and consumed!

Our household electricity is supplied at 240volts. If you don’t switch on any appliance in your house, you will be consuming zero power because 240V times zero current is equal to zero. Now think about it, the generator must be kept running at idling so as to supply voltage in your wires. This ensures that as soon as you turn on a device, it gets voltage immediately and begins to draw current.

Who pays the cost of keeping that generator running when your demand is zero? This is the reason why power purchase agreements between Kenya Power and all power producers (both IPPs and KenGen) cater for “capacity charges”. This is the fee for keeping generators running at idling speed (they are NOT sitting idle!) waiting for customers to draw power when needed.

If you have ever been in a house that runs on a petrol/diesel generator, you may have observed that sometimes when a heavy consumer (e.g., the kettle) is switched on, the lights dim momentarily as the generator tries to keep up with demand. You can even hear the generator straining to keep up. To avoid this effect, Kenya Power connects generators with higher capacity than the demand from consumers.

The capacity charges are levied on an hourly rate any time the generators are running regardless of the amount of power being drawn by consumers. According to the 2021/22 audited financial report of KenGen, its total revenue from electricity was Sh32.7 billion. Out of this, Sh25B was from capacity charges while only Sh7.7B was from actual energy supplied. In other words, the capacity charge is over three times the energy charge!

Unfortunately, being private companies, the financial reports of IPPs are not readily available, but I would expect to see the same trend – capacity charges are greater than energy charges several times over.