Why we asked GenCos to reduce generation — TCN

THE Transmission Company of Nigeria (TCN) on Monday gave reasons behind its directive to the Generation Companies (GenCos) to reduce power generation saying this was in a bid to ensure grid stability.

It said at a point, the System Operator, charged with the responsibility of power flow from the grid noticed a high system frequency of more than 50HZ.

The General Manager, Public Affairs unit of the company, Mrs Seun Olagunju, in a statement she issued in Abuja explained that there is a power flow balance equation that determines system frequency, with the target of operating at 50HZ frequency.

According to her, the option to bring down the frequency to the normal 50HZ to avoid system disturbance was for either the Distribution Companies to absorb more load or Generation companies to reduce generation.

She maintained that somehow, for unknown reasons, Distribution Companies DISCOs failed to take more load as generation increases.

This, she said, led to the decision of the System Operator to ask the GENCOs to reduce generation to ensure grid stability.

The statement reads in part: “In general, electricity is not stored, but is used as it is being generated. Therefore at any particular moment in time, there is a power flow balance equation that determines system frequency, with the target of operating at 50HZ frequency.

“It is the duty of the system operator to monitor the power flow on the national grid to ensure optimal operating conditions; this will ensure the system is operated at a frequency close to 50HZ, and at voltages within tolerable limits.

“Recently, high system frequency (more than 50HZ) has been observed, necessitating corrective measures. The options to bring down the frequency to 50Hz are: Distribution Companies to absorb more load, or Generation companies to reduce generation.

“The first option is the appropriate line of action. However, due to inexplicable reasons, some DISCOs failed to take more load as generation increases.

“The directive to GENCOs to reduce generation is imperative to maintain the integrity of the grid, as frequency higher than 50HZ could result in system disturbance.”

Olagunju noted that the directives are issued with a high sense of duty and responsibility to the nation and the entire electricity industry adding that at normal operating frequency of 50Hz, the active power generated is equal to the active load consumed and losses.

However, she said if the generated power is more than the load connected, the frequency rises higher than 50Hz, which can result in system disturbance.

“To correct this imbalance, the system operator whose duty it is to maintain system stability has no choice than to ask the generating stations to drop the load to sustain the network integrity. This is the practice all over the world.

“On the contrary, if the load connected is higher than the generated power, the frequency drops below 50Hz and can also lead to system collapse,” the statement reads.

She stated that the highest generation level stands at 4,650MW while the wheeling capacity of TCN is 6,500MW.

“It is therefore not a wheeling capacity challenge but a demand side management problem from some DISCOs rejecting available power,” it concluded.‎