Prestea - Bogoso 161kV Transmission Upgrade Project / Ghana
Design, Supply, Installation and Commissioning of a 161kV Transmission Line and Substation.
To improve power evacuation from the western to the northern part of Ghana, the existing Prestea Bogoso 161kV transmission line was to be decommissioned and replaced by a new 161kV double circuit, twin-bundle conductor transmission line and the 161/34.5kV outdoor substation at Bogoso was to be upgraded. The contract was put out to international competitive tendering and BES was awarded the contract as the best evaluated bidder.
Products and services supplied
The works included the decommissioning of the existing 161kV power line, the complete design of the new line, demolition of the old line, construction of new foundations, erection of towers, installation of fittings, stringing of conductor and OPGW shield wire and their termination at the Prestea and Bogoso Substations.
The 34.5kV obsolete indoor switchgear was decommissioned and replaced with a new 34.5kV metal clad air insulated switchgear; two sets of three-phase 161kV pantograph disconnector switches were decommissioned and replaced by new ones and an emergency 50kVA diesel generator set was supplied and installed. BES also designed, supplied and installed a new mosaic MIMIC control and metering panel board and an annunciator panel to control the entire 161/34.5kV substation. All the installed equipment was commissioned by BES.
The work required careful planning as there were strict limits to power outages due to the fact that the existing line and substations were the main supply to large gold mines in the area. To that effect the supply was re-routed through the temporary construction of a loop-in loop-out solution for the transmission line and of a by-pass for the substation.
BES arranged the finance for the project through its UK bankers with support from the Export Credit Agency of the UK Government.
The project was completed on time and within budget and the power outages were kept to a minimum as the customer required.