A paradoxical risk regarding the adoption of solar energy as a power source for commercial and industrial customers was loadshedding, vertically integrated independent power producer New Southern Energy CEO Dave Masureik told Engineering News & Mining Weekly at the Africa Renewables Investment Summit in Cape Town last month.

The rotating scheduled power cuts imposed by national electricity utility Eskom, called loadshedding, had been both a blessing and a curse for the solar power sector.

“Loadshedding has increased the uptake of solar, but if you don’t install batteries or back-up power, under the regulations, you have to shut down the inverters,” he reported. (Inverters convert the direct current electricity produced by solar panels into alternating current electricity, which is what is used by transmission grids.)

“For a solar inverter to work, you need something to form a grid; if the Eskom grid goes away, because of loadshedding, then solar energy can’t work,” he explained. However, batteries or generators can form a grid, thereby allowing solar panels to continue to supply electricity.

It was not merely a matter of solar panels charging a battery while the battery was supplying power. If the capacity of the solar array was great enough, it could both charge the battery and supply electricity directly, because of the ‘grid forming’ role played by the battery.

“In South Africa today, solar should always be coupled with batteries,” he highlighted. “Batteries increase the capital costs, but they mitigate against loadshedding.”

During the panel discussion, Masureik pointed out that the solar energy market in South Africa had matured over the past five years. It had moved from having potential to concrete opportunities and projects. The technical risks with solar were known and managed.

Solar power systems needed to be properly designed, correctly installed, and properly operated. Once operational, they needed to be cleaned and correctly maintained.

“We include all of that in our offering,” he assured. “If you don’t have that, you’re at serious risk of underperforming.”

He also cautioned that each solar power site was different (even if they were close to each other). The nature and location of each site had to be taken into consideration when designing the solar power system to be installed there.