Embattled power utility Eskom has announced that stage 4 load shedding will continue for the rest of the week, with energy analysts warning that the situation could deteriorate further in the coming months.
Fortunately, South Africans who wish to produce their own power can use a combination of solar panels to generate, and battery backup systems to store electricity.
Solar panels use photovoltaic (PV) cells to convert sunlight to electricity. When a panel of PV cells absorbs light, electrons that generate electric current are released. The electric current produced can be used as a direct power source or stored in batteries as a backup power solution.
According to data provided by the City of Cape Town, there are two main types of solar PV systems to choose from:
Grid-tied SSEG systems
These are connected to the electricity grid either directly or through your property’s internal wiring. There are two types of grid-tied systems:
- Grid-tied feed-in system (also known as an SSEG with export option): the electricity generated by the PV system is used on the property. Excess electricity generated from the system is fed back into the electricity grid,
- Grid-tied non-feed-in PV (also known as an SSEG without export option, with reverse power flow blocking): the electricity generated by the PV system is used on the property only when there is a demand for it. Excess electricity generated is blocked from feeding back into the grid.
Off-grid or standalone SSEG systems
These systems have no connection to the grid. They are physically separated and electrically isolated from the grid. An example would be connecting a pool pump directly to a solar PV system instead of connecting it to the building’s wiring.
The costs of installing solar PV panels will vary widely depending on the use case of each homeowner and what appliances they are looking to power – as well as the number of solar panels they install.
Pricing from energy specialists SolarAdvice shows that a lower-end system, built specifically to power some appliances during load shedding for a couple of hours, will set users back R34,700.
By comparison, a ‘starter’ off-grid power kit that will power small households for a short time will cost around R49,000. Those looking for a kit to give power continuously can expect to pay upwards of R90,000.
Speaking to MyBroadband in August, Nick Roche, chief product officer at energy company Rubicon, said that it will cost around R250,000 to install a power generation and storage system that is sufficient to take a small household completely off of Eskom’s grid.
Roche said when it came to the ideal system for households, there was no “one-size-fits-all” solution. Factors you should consider will include:
- System size – Amount of output power and capacity
- Roof details –Size of the roof section with sufficient exposure to the sun
- Autonomy – How long the system must keep providing power during periods of low generation.
- Budget – How much you want to spend.
Roche said there were a few easy wins to decrease the required system capacity and costs when planning a solar system. He added that South Africans may be better served by making smaller changes first before moving completely off the grid.
“Firstly, hot water geysers should be converted to alternative supplies such as solar energy,” Roche said. “Next, converting the stove and oven to gas can greatly reduce usage, as these appliances are among the most power-hungry. Alternatively, induction plates have a much lower electrical load.”
Lastly, Roche recommended updating certain other loads or old appliances to energy-efficient options – such as LEDs for lighting or using modern fridge and freezer technologies.