Alternative energy system installers, AdSolar EPC chose photovoltaic (PV) innovation by Schneider Electric to power the creation of a new 22-room Rhino Ridge luxury game lodge bordering the Hluhluwe Game Reserve in KwaZulu-Natal.
Photo credit: Isibindi Africa
Sebastian Brogan, renewable energy consultant and project manager at AdSolar EPC, says that an alternative energy solution was a necessity as the national power grid supply to the building site was intermittent and capped at 20 amps.
“This limited power supply was certainly not sufficient for the loads required by the new resort,” states Brogan.
The project team thus worked on designing a system that would meet four prerequisites: to fall within budget, to integrate with a back-up generator, to utilise the available national grid supply, and to be deliverable within a very short period of time.
“The budgetary constraints forced us to scale back our full-proposed delivery to some extent, resulting in the panel array and the battery bank to be a third of the ideal size initially, but we could not skimp on the inversion,” says Brogan.
Consequently, six Schneider Electric Conext XW+ 8.5kVA hybrid inverters were selected to form the 51kVA three-phase hub that would deliver the required power.
Leon Hailstones, transactional products channel manager for southern Africa’s Solar Business at Schneider Electric, explains that Conext XW+ is an adaptable single-phase and three-phase hybrid inverter with grid-tie functionality and dual AC power inputs.
Available solar charge controllers, monitoring, and automated generator control modules enable further adaptability of the system. From a single Conext XW+ unit, to clusters up to 102 kW, the Conext XW+ is a scalable system that allows for the integration of solar capacity as required.
“Adaptable and scalable, the Schneider Electric Conext XW+ system is the one solution for grid-interactive and off-grid, residential and commercial, solar and backup power applications,” adds Hailstones.
Brogan says that the system at Rhino Ridge will be large enough to generate all of its own power, but until then the 20kW solar PV array has to do its best to keep the batteries topped-up.
During the continued building stage this should be sufficient, but – just in case – there is a large generator that will be sent a signal from the system to auto-start and charge the batteries to full.
“When we arrived on site to commission early in January 2015 everything seemed to be ready. Seventy-eight panels at a 28 degree angle facing true north, seven charge controllers regulating the voltage, six hybrid inverters, and forty eight battery cells, all installed and wired up correctly. Integration with the national grid supply was in place and all we had to do was flick the switch. But just before we did that we thought we had better check the supply. Red phase was fine at 230V, but the white and blue phases were 150V and 80V respectively.
“This imbalance rendered the national grid supply almost entirely useless. Our system, however, delivered the full power and stands ready for the national grid supply to rectify issues on its end. In the meantime the battery bank, which can deliver 2376 amp hours of power in as little as a five-hour period, is getting ample charge for its duties from the PV array and the generator when necessary,” concludes Brogan.