The first solar power generation system to be installed at ACTOM’s main factory complex at Knights, Germiston, in Gauteng went into operation in mid-2023.
The grid-tied PV solar system at ACTOM MV Switchgear’s Knights factory is designed to generate around 1 MW of power.
MV Switchgear is the largest consumer of power among the various manufacturing divisions at the Knights site and was therefore selected as the first division to be equipped with a solar generation system.
ACTOM plans to introduce solar generation systems progressively at other factories on the site as well as at group factories and workshops elsewhere in Gauteng and around the country in due course.
After installation and commissioning was completed in June, the solar installation at MV Switchgear, went into operation in July. It is a grid-tied PV solar system, designed to generate around 1 MW of power, which is about equivalent to the division’s power consumption at peak load and about 50% of the peak load drawn by all the factories at the Knights site.
“We consequently expect the system to reduce the Knights site power consumption from the national grid by up to 50%, which represents a significant cost saving for us,” commented Rhett Kelly, MV Switchgear’s Design & Development Manager. He said the reduction in power consumption from the grid can only be roughly estimated at this stage, as the solar generation system has not yet been in operation for long enough for a more accurate figure to be determined.
“MV Switchgear’s energy consumption and thus its electricity bill are expected to drop by up to 75%. This figure will depend on the weather and the extent of operations carried out during the night hours when the solar system is unable to generate power,” he added.
The system comprises two identical 550 kW grid-tied PV solar-powered inverter installations, which have been installed, respectively, at the two main transformer locations in MV Switchgear’s network supplying power to various parts of its extensive factory. The solar panels are installed on the main factory roof and are linked to the inverter stations at the two transformer locations.
Each inverter station comprises five 110 kW inverters, an inverter collector box and a data management system. “Each inverter system is tied into the low voltage electrical installation of its respective main distribution board. If the power generated at the inverter station exceeds the power demand at its location, any excess power generated is fed back-via the transformer into the Knights site 11 kV ring network and can be used to supplement the power demands at other locations on the site. This ensures that no PV generated power goes unused,” said Kelly.
Johan Jordaan, Technology Development Specialist at MV Switchgear, further explained: “The system operates without battery backup and therefore requires ac (50 Hz) mains supply to support the load when inconsistent or no power can be generated from the solar panels, due to overcast conditions or at night. By definition, a grid-tied solar generation system without a battery storage system cannot operate in isolation, its purpose is to reduce the energy consumed from the grid.”
For some time, the division has relied on diesel-powered generators as an alternative source of 50 Hz ac power to the mains supply from the grid, as is required typically – and increasingly in recent times – when loadshedding occurs.
“Here again, as with mains supply from the grid, our adoption of solar generated power enables us to reduce our dependence on expensive diesel-powered generation. We cannot do without it, but having brought solar generation into play, we need it less than previously and can achieve substantial energy cost savings as a result,” Jordaan said.
For more information visit: www.actom.co.za
