There aren’t many examples of mini-grids in South Africa. This is partly because of the country’s universal electrification policy, which aimed to get power into all homes by 2012, through grid or non-grid supply, explains Damian Conway with the Sustainability Institute Innovation Lab (SIIL) outside Stellenbosch in the Western Cape.
For those who can’t connect to the grid, non-grid options usually involve solutions that are geared towards individual homes’ needs.
‘This could be single appliance solutions, such as individual solar lights or cellphone chargers. Or it could involve a system where a small PV panel and battery run basic appliances in a single home, such as lights and a TV,’ he says.
A mini-grid is a step between the national grid-scale solution, and the single solar home solution: it’s an off-grid, electricity generation system that links and supplies anything from 10 to 150 neighbouring households. In the African context, it’s usually used in rural communities that are too far from national infrastructure to be connected to the electricity supply network. In South Africa, it’s regarded as a stop-gap until the state links a community to the grid, and therefore hasn’t been used much.
A mini-grid needs fairly costly infrastructure – an energy source such as PV panels or a wind turbine, batteries, and a distribution and metering system – as well as technically competent maintenance and operating systems, says Conway.
It is generally only viable in a high-density community. The longer the distance between the power source and the user, the greater the energy loss along the cables, which calls for a higher voltage system (this means more heavy-duty hardware and higher technicians’ skill levels).
Zonke Energy’s Hendrik Schloemann scouted about Cape Town to find a community in which to pilot a fledgling mini-grid idea, to test both the technology as well as the financial model.