The Load Shedding Problem
South Africans have lived with load shedding for years, but the intensity escalated dramatically in recent years. At its worst, Stage 6 load shedding meant up to 12 hours without power per day — a situation that is not just an inconvenience, but a genuine threat to household wellbeing and business viability.
For homes, load shedding means spoiled food, disrupted sleep, inability to work from home, and the constant stress of unpredictability. For businesses, it means halted production, lost trading hours, damaged equipment, and unhappy customers. The cumulative economic cost runs into billions of rands annually — and most of that damage is entirely avoidable.
The frustrating reality is that load shedding is a structural problem with the national grid, not a temporary blip. The right response isn't to simply wait it out — it's to remove your dependence on the grid during outages entirely.
How Solar + Battery Solves It
A hybrid solar system with a properly sized battery bank is the most effective solution to load shedding available to homeowners and businesses today. Here's how it works:
- During daylight hours, your solar panels power your property directly and simultaneously charge your battery bank.
- When load shedding begins, your hybrid inverter detects the grid failure within milliseconds and seamlessly switches to battery power — fast enough that most appliances and devices don't even register the transition.
- Your essential loads continue running on battery power for the duration of the outage.
- When the grid returns, the inverter switches back and resumes charging the battery from the grid or solar, ready for the next outage.
The entire process is automatic. You don't flip switches, you don't wait for a generator to start, and you don't lose your alarm system or Wi-Fi. It simply works — quietly, reliably, and continuously.
Essential vs Non-Essential Loads
One of the most important concepts in designing a load shedding solution is understanding the difference between essential and non-essential loads. Your inverter is connected to a dedicated essential loads circuit — meaning only the appliances on that circuit are backed up during an outage. High-draw appliances remain on the grid supply.
Typical essential loads (back these up)
- Lights (LED throughout makes a big difference)
- Television and media equipment
- Wi-Fi router and internet equipment
- Phone and laptop charging
- Security alarm system and electric fence
- CCTV cameras and access control
- A few plugpoints for general use
- Smaller kitchen appliances (microwave, coffee machine)
Non-essential loads (leave on the grid)
- Electric geyser (unless you have solar water heating)
- Pool pump
- Air conditioning (high draw — consider scheduling around solar)
- Electric oven and stove
- Tumble dryer
By keeping high-draw appliances off the battery circuit, you dramatically extend how long your battery lasts during an outage — allowing a smaller, more affordable battery to cover longer outage windows.
Sizing for Load Shedding: How Much Battery Do You Need?
Let's work through a practical example for Stage 6 load shedding, which can produce a 4-hour outage window. Assume an average essential load of 800W — lights, TV, Wi-Fi, and some plugpoints running simultaneously.
- Energy required: 800W x 4 hours = 3.2 kWh
- Add 20% buffer for efficiency losses and partial discharge protection: 3.2 x 1.2 = 3.84 kWh
- A 5 kWh battery with 90% DoD gives approximately 4.5 kWh usable — comfortably covers this scenario
If you're in a Stage 6 situation with two outage slots per day (potentially 8 hours total), you'd want a 10 kWh battery or larger. Your solar panels recharge the battery between outages during daylight hours, restoring capacity for the next slot.
For businesses with higher loads — servers, point-of-sale systems, lighting across large spaces — a 10–30 kWh system is more appropriate. Our team will size this precisely based on your actual load profile.
Tips for Maximising Your Battery During Outages
- Switch to LED lighting everywhere: A standard incandescent bulb uses 60W. An LED equivalent uses 8–10W. Across 10 lights, that's a 500W saving — a massive reduction in battery drain.
- Avoid running the kettle or toaster during load shedding: These are 2,000W+ appliances that will drain your battery in minutes. Boil water before the scheduled outage window.
- Pre-cool or pre-heat your space: If you have air conditioning, run it before load shedding starts so you're starting from a comfortable temperature.
- Set your geyser timer to heat before the outage window: Your geyser is insulated — water heated before load shedding stays hot for several hours.
- Monitor via your inverter app: Most modern inverters (Sunsynk, Victron, Sungrow) offer real-time monitoring via a smartphone app. Use it to see your battery state and adjust usage accordingly.
Why a Hybrid System Beats a Generator Long-Term
Many households and businesses turned to petrol or diesel generators as a load shedding stopgap. While generators provide power, the comparison with a solar-battery hybrid system is stark:
- Running costs: A generator consuming 1.5 litres of petrol per hour costs R35–R45 per hour to run at current fuel prices. A hybrid system running on stored solar energy costs effectively nothing per hour.
- Noise and fumes: Generators are loud, produce exhaust fumes, and can't be run indoors or in garages. Hybrid inverters are silent and odourless.
- Maintenance: Generators require regular servicing, oil changes, and fuel storage management. Hybrid systems require almost no maintenance.
- Reliability: A generator that hasn't been run in weeks may fail to start exactly when you need it. A hybrid system runs continuously and is always ready.
- Security: Generators are a theft target. A hybrid system is fixed infrastructure that can't be stolen from your roof or wall.
The upfront cost of a hybrid system is higher than a generator, but the total cost of ownership over 5–10 years — factoring in fuel, maintenance, and replacements — makes the hybrid system the clear winner. And unlike a generator, your hybrid system keeps paying you back through electricity bill savings long after load shedding is a distant memory.