How much it really costs to go completely off-grid in South Africa

Key topics:

• Off-grid solar system costs start from around R150,000

• Prices have dropped up to 17% compared to last year

• Larger homes require higher inverter and battery capacity

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By Hanno Labuschagne

South African households can go entirely off-grid with a solar PV and battery backup power system, starting from around R150,000, depending on their power usage.

Many frustrated households expressed keen interest in ditching their Eskom connections completely during the severe load-shedding experienced in previous years.

That interest would quickly wane once a solar power installer explained exactly how much they would need to spend to go off-grid.

Filling the generation gap left by prolonged periods of inclement weather requires roughly two to three times the panel and battery capacity of a grid-tied system that can meet 80% to 90% of their demand.

That is because solar power generation efficiency can drop to less than 10% of normal output during particularly gloomy days.

It was far more cost-effective to get a system that could supply just enough backup to last through load-shedding or reduce demand from the grid so that it would pay itself off in the shortest time possible.

However, the prices of solar panels, inverters, and batteries have plummeted in recent years, which has made it cheaper than ever to invest in self-generation.

While load-shedding is less of a concern, Eskom and many municipalities have begun implementing higher fixed charges, making it significantly more expensive to remain grid-tied.

Many utilities also have complex and costly requirements for connecting hybrid systems to their grid. Going off-grid eliminates this hassle.

MyBroadband configured off-grid systems from major solar power installer Solar Advice for households with four different monthly energy consumptions to see how much it costs to go off-grid in late 2025.

To ensure the households could meet all their instantaneous demand at any given time, the minimum inverter capacity we chose was 10kW.

This was increased to 15kW for the more power-intensive households. Many homes could get away with a smaller inverter by avoiding the use of high-demand appliances simultaneously.

However, this would require additional effort compared to having a grid-tied system, where any supplementary power can simply be taken from the municipality or Eskom.

A parade of panels and battery barrage

For the solar panels and batteries, we used an oversizing factor of 2.5 over what the household would require to meet 80% to 90% of its regular demand.

The battery capacity was based on the average nighttime energy consumption. To calculate this, which assumes 60% of a home’s energy is used at night and 40% during the day.

Homes that shift more of their energy demand to daytime hours could get away with smaller batteries, but once again, this would require extra effort compared to simply using a grid-tied system.

For example, a household that consumes 450kWh in a month would use about 15kWh in a day. If 60% of that were used overnight, they would consume roughly 0.75kWh per hour.

With our technical parameters in place, we used Solar Advice’s online system sizing tool to configure the most cost-effective system for each energy usage profile.

For a small household with an average consumption of 450kWh, the cost of a fully off-grid system from Solar Advice meeting our criteria was approximately R150,453, 13% cheaper than a year ago.

For households with 600kWh and 900kWh consumption, off-grid systems currently cost 14% less than they did a year ago.

Our off-grid system for large households with 1,200kWh consumption costs R301,402, about 17% less than at the same time last year.

Technical parameters of configured systems

Detailed system specifications

*This article was first published by MyBroadband and is republished with permission.