Ernest Mupwaya, AEDC CEO

The Abuja Electricity Distribution Company (AEDC), has explained that the present channel of electricity supply nationwide forced it to embark on loadshedding to prevent system collapse.

It noted that the structure of power supply in Nigeria today makes the transportation of electricity through a middle man which the Transmission Company of Nigeria (TCN) represents, inevitable.

Using power supply in Karu, a satellite town of the Federal Capital Territory, Abuja as an example, AEDC expressed optimism that TCN will see value in a line as well as transformer upgrade from 2 x 60MVA to 2 x 100MVA at Karu considering the ever growing population in the area.

It maintained that “the power supply issue in Karu axis is largely as a result of transformer capacity limitation on the TCN trading points, resulting in massive loadshedding as a result of lack of capacity for more load.

“Conscious of the need to improve on the supply in Karu, AEDC has radiated an additional 33kV fdr (k5) & made it dual with k4 at Karu aimed at improving power supply and flexibility of the network. The evacuation of power from Keffi, which is currently on going will reduce the challenges at Karu TS.”

Using technical terminologies, AEDC stated as follows that: “The TCN facility in Karu is a 2 x 60MVA transformer from which we have radiated 5 feeders viz K1 – K5.

“While k1 – k3 is serviced from TR1, TR2 caters for k4 & k5. Using a power factor of 0.8, the capacity of the 2 x 60MVA transformers translates into 96MW.

“Two load categories exist in most DisCo network and AEDC is not an exception. They are line load and the 11kV load.”

Its Load Analysis shows that: *Fdr. K1* Line Load = 15.0 11kV fdr. = 14.5
Total. = 29.5; *Fdr. K2*
Line Load = 18.5 11kV fdr = nil
Total = 18.5; *Fdr. K3* Line Load = 3.7
11kV fdr. nil Total = 3.7; *Fdr k4*
Line Load = 16.0 11kV. While A23 is 14.7, J22 is 19.5 Total = 50.2 and *Fdr. K5* Line Load = 24.0 11kV fdr. = 6.3 on J32 Total = 30.3.”

According to the AEDC, “Industry practice for loading a transformer is often 75%. But assuming we deviate from this and apply 80%, which we are sure will never be done by TCN, the total load that TCN will allow on the 2 x 60MVA transformers will be 76.8MW at anytime yet we have need for 132.5MW.

Since we cannot provide for the balance of 55.7MW, which translates into 30 percent of our customers, we are forced to embark on a regime of loadshedding at any point in time. It also means that TCN has both line and transformer limitation.

“In the short run, we are evacuating power through the reactivation of our 33kV line that runs from Keffi TS to J32 injection substation (2×7.5MVA) at Nyanyan Gwandara & about 10MW of the line load on K5.

“In the long run, we intend to radiate a different feeder from Keffi TS to Karshi through the Keffi-Abuja bypass road.

“We also plan to provide two additional injection substations on feeder k2 & k4 in order to reduce the level of line load for better operational flexibility and improve power supply to our customers in that axis.”