The Northern Cape-based Khobab and Loeriesfontein wind farms announced last month that they had received their main transformers, which were transported by road from Johannesburg.
The 160 MVA transformers are to be housed in substations, from where all the generated power from the wind farms will be transferred to the national grid. “These transformers are responsible for increasing the voltage from 33 kV to 132 kV, which is the voltage required to transfer power to [State-owned utility] Eskom’s national grid,” explains Khobab wind farm project manager Kevin Foster.
Each wind turbine is connected to a step-up transformer, which boosts the generating output of the wind turbine generator from 690 V to 33 kV. A step-up transformer is located at the base of each wind turbine, from where the cables throughout the wind farms transport the respective 33 kV of electricity to convene at the substation where the main transformer is situated.
The main transformers, which were manufactured by electromechanical equipment company Actom, play an important role in a wind farm’s power generation efficiency.
Power infrastructure solutions provider Conco is responsible for the electrical component of the balance of plant works, including the engineering, procurement and construction of the medium-voltage collector system, substation and overhead line connection.
About 500 workers are currently employed by the two wind farms, 70% of whom are from the Loeriesfontein community and range from general labourers to machine operators. “We are pleased that construction is on track so far – in fact, we are ahead of schedule on a number of components,” added Loeriesfontein wind farm project manager Leo Quinn.
In June this year, all turbine foundations at Loeriesfontein were completed; Khobab is expected to complete all its turbine foundations by the end of this month.
Transportation of the various wind turbine components to the two farms started in April this year.
The Loeriesfontein Wind Farm achieved more than a million hours without a lost-time incident in October.
The wind farms officially started operations in September.
The wind farms form part of Round 3 of the Renewable Energy Independent Power Producer Procurement Programme and will be managed in terms of construction and operations by Mainstream Renewable Power South Africa.
Both are expected to be operational by December next year.