Solar Inverters Explained: Choosing the Right Inverter for Load Shedding

If solar panels are the muscle of a solar system, the inverter is the brain. It converts the direct current (DC) produced by your panels and stored in your batteries into the alternating current (AC) your home uses, and it decides moment to moment whether to draw from solar, battery or the grid. Choosing the right inverter is the most important decision for surviving load shedding.

The three types of inverter

• Grid-tied inverters: the cheapest option. They feed solar power into your home and the grid during the day, but they switch off when the grid goes down, so they offer no load-shedding backup on their own.
• Hybrid inverters: the most popular choice in South Africa. They manage solar, batteries and the grid together, and switch over automatically during an outage to keep selected circuits running.
• Off-grid inverters: built to run a property entirely on solar and batteries with no grid connection, used on farms and remote sites.

For a deeper look at how these map to full systems, see our guide to grid-tied, hybrid and off-grid systems.

Sizing an inverter for your home

Inverters are rated in kilowatts (kW), which is the maximum load they can run at once. To size one, add up everything you want to run during load shedding at the same time:

• Lights, TV, Wi-Fi and phone chargers use very little, often under 0.5 kW combined.
• A fridge and freezer add roughly 0.3 to 0.6 kW.
• High-draw appliances like kettles, geysers, microwaves, stoves and pool pumps each pull 1.5 to 3 kW and quickly add up.

Most SA homes land on a 5 kW or 8 kW hybrid inverter. Trying to run a kettle, oven and geyser at the same time as everything else is what trips an undersized inverter, so it helps to stagger heavy appliances. Our system size calculator gives you a quick starting estimate.

Match the inverter to panels and batteries

Three numbers need to work together: inverter size, panel array size and battery capacity. A common balanced setup for a medium home is around a 5 kW inverter, 5 to 6 kW of panels and 5 to 10 kWh of battery. The inverter and battery determine how much you can run during an outage, while the panels determine how quickly the battery recharges.

Quality and compliance matter

Stick to reputable inverter brands with local support and warranties, and confirm the unit carries a valid NRCS Letter of Authority so it is legal to use in South Africa. You can browse leading inverter brands on our brands directory. Installation must be done by a qualified person who issues a Certificate of Compliance.

Ready to spec a system? Get free quotes from verified installers who will size the inverter to your exact needs.