The Ghana Grid Company (GRIDCo) has successfully installed and commissioned a new 120/145MVA Siemens Energy power transformer at the Afienya Substation.

The project marks a major upgrade from the previous 66MVA transformer. It more than doubles the station’s capacity. It also strengthens the grid to meet rising demand across Accra, Dawhenya and surrounding communities.

According to Dr Benefit E.A.K Patu, Supervisor for Electrical Maintenance, the project was driven by the urgent need to address overloading in the area.

He explained, “The [capacity] of the original transformer (50/66MVA) was nearing its limit due to increasing demand from ECG’s extended distribution lines.

"With the new 120/145MVA transformer, we now have the capacity to accommodate more load and extend a reliable power supply to more communities.”

The upgrade doubles capacity at the Afienya Substation. It also strengthens the National Interconnected Transmission System (NITS). This ensures a more stable and efficient power supply for current and future needs.

The installation involved several critical stages. Engineers positioned the transformer on its foundation and completed the full assembly of its components and accessories.

The team carried out oil filtration to ensure the transformer core and conservator were properly filled. The OLTC unit was also prepared with oil to support efficient operation.

During oil treatment, engineers focused on reducing moisture content to acceptable PPM levels. Continuous monitoring showed single-digit results.

These were submitted for technical validation and subsequently approved.

The Protection and Control team played a key role in ensuring safe operation.

Led by Francis Koomson, the team decommissioned old cables, installed new wiring and conducted comprehensive protection tests, including trip testing.

“Our responsibility was to ensure the transformer operates safely. We verified that in the event of a fault, the system will trip as expected,” he stated.

Following extensive testing and validation, the transformer was approved for commissioning.

The project was executed entirely by GRIDCo engineers. The team was led by Dr Patu, with support from Francis Koomson and Albert Baiden-Amissah, Supervisor for Line Maintenance.

The successful commissioning highlights GRIDCo’s commitment to operational excellence, innovation and reliability in power transmission. It also reinforces the company’s role as a backbone of Ghana’s power sector.