How to Choose the Right Inverter for Load Shedding in South Africa
Home Backup Power | Updated February 2026
Load shedding has become part of daily South African life. Whether you are on Stage 2 or Stage 6, finding yourself in the dark for 2-4 hours at a stretch is frustrating — and for many households, genuinely damaging to food, work and security. A well-chosen home inverter system solves this problem permanently.
But walk into any electrical shop and you face a wall of options: pure sine wave vs modified sine wave, 1kVA vs 5kVA, lead-acid vs lithium, hybrid vs standalone. This guide cuts through the confusion and gives you the straight South African picture on what to buy, what to spend and what to avoid.
Step 1: Calculate Your Load
The single most important step is knowing how much power you need. List every appliance you want to run during load shedding and note its wattage:
| Appliance | Typical Wattage | Priority |
|---|---|---|
| LED lights (x6) | 60W | Essential |
| Wi-Fi router | 15W | Essential |
| Laptop/PC | 60-150W | High |
| LED TV (55") | 80-120W | Medium |
| DStv decoder | 30W | Medium |
| Fridge (medium) | 150-200W running / 600W startup | High |
| Microwave | 900-1200W | Low (brief use) |
| Kettle / toaster | 1500-2200W | Avoid on inverter |
Rule of thumb: Add up the wattage of everything you want to run simultaneously. Choose an inverter rated at least 20-25% higher than that total to handle startup surges and leave headroom.
Step 2: Pure Sine Wave vs Modified Sine Wave
You will see modified sine wave inverters at lower prices — do not choose them for a home setup. Here is why:
- Modified sine wave produces a stepped, choppy waveform. Fine for simple resistive loads, but it causes problems with motors (fridge compressors, ceiling fans), LED drivers, CPAP machines and audio equipment. It can shorten appliance lifespans significantly.
- Pure sine wave produces clean AC power identical to Eskom's supply. Every appliance in your home will run exactly as intended — no humming, no overheating, no damage risk.
For a home backup power system, always choose a true sine wave inverter. The price difference is modest and the protection it offers your appliances is worth every rand.
Step 3: Choosing the Right Inverter Size (kVA)
| System Size | What It Runs | Best For |
|---|---|---|
| 1kVA - 1.5kVA | Lights, router, TV, phones, laptop | Apartment, small home |
| 2kVA - 3kVA | Above + fridge, ceiling fan | Medium family home |
| 4kVA - 5kVA | Above + additional appliances | Large home, home office |
| 8kVA+ | Near full-house coverage | Large property, business |
For most South African family homes protecting essentials plus a fridge, a 3kVA system is the sweet spot. If you are only protecting lights, internet and screens, 2kVA is sufficient.
Step 4: Standalone Inverter vs Hybrid Inverter
Standalone / UPS Inverter
Connects to your battery bank and switches to battery when grid power fails. Charges batteries from grid when Eskom is on. Cannot accept solar panels. Lower cost upfront, but a dead-end if you later want to add solar.
Hybrid / Solar Inverter with MPPT
Does everything a standalone does, but also accepts solar panel input via a built-in MPPT charge controller. During daylight hours your solar panels charge batteries and offset your grid draw — even when Eskom is on. This is the smart long-term choice.
Recommendation: If you can stretch the budget, buy a hybrid inverter now. Even if you cannot afford solar panels immediately, you will be able to add them later without replacing your inverter — true future-proofing.
Step 5: Battery Type
Sealed Lead-Acid (AGM/Gel)
- Lower upfront cost (roughly R1,500-R3,500 per 100Ah)
- Proven technology, widely available in South Africa
- Should not be discharged below 50% — you only use half the capacity
- Lifespan: 3-5 years with proper care
- Heavy and bulky; emits hydrogen gas during charging
Lithium Iron Phosphate (LiFePO4)
- Higher upfront cost — but we stock the Nava Solar 5kWh 48V at R13,500 incl VAT
- Can safely discharge to 80-90% — you use nearly all the capacity
- Lifespan: 8-15 years (2-3x longer than lead-acid)
- Lighter, faster charging, better in South Africa's heat
- Safe for indoor installation — no gas emission
Read our detailed comparison: Lithium vs Lead-Acid Batteries for Home Backup Power.
Step 6: How Much Battery Capacity Do You Need?
- Determine your total load in watts (e.g. 400W)
- Decide how many hours of backup you need (e.g. 4 hours for a Stage 4 double slot)
- Energy needed: 400W x 4h = 1,600Wh = 1.6kWh
- For lead-acid (50% usable): you need 3.2kWh of rated capacity
- For lithium (85% usable): you need only 1.9kWh of rated capacity
This is why lithium gives you so much more real-world runtime from the same rated capacity.
Estimated System Costs for South Africa (2026)
| System | Approximate Installed Cost |
|---|---|
| 1.5kVA + 100Ah AGM (essentials only) | R10,000 - R15,000 |
| 3kVA + 200Ah AGM (fridge + essentials) | R22,000 - R32,000 |
| 3kVA Hybrid + 100Ah Lithium | R28,000 - R40,000 |
| 5kVA Hybrid + 200Ah Lithium + 2kWp Solar | R55,000 - R85,000 |
Installation and Safety
A properly installed inverter system should be wired by a qualified electrician and connected to a dedicated DB board circuit. Key points:
- Inverter and batteries should be in a ventilated, cool space — heat shortens battery life
- Cable sizing must match the inverter current draw — undersized cables create fire risks
- Install a DC circuit breaker between batteries and inverter
- Lead-acid batteries produce hydrogen gas during charging — never install them in an enclosed room without ventilation
Ready to get a professional assessment? Contact us or use our Home Backup Systems request form for a free quote.
Frequently Asked Questions
What size inverter do I need for load shedding at home?
For a typical home running lights, TV, router and phone chargers, a 1kVA to 2kVA inverter is sufficient. Add a fridge and step up to 3kVA-5kVA. Always size at least 20% above your calculated total load to handle startup surges.
What is the difference between pure sine wave and modified sine wave?
Pure sine wave produces clean AC power identical to Eskom — safe for all appliances. Modified sine wave is cheaper but can damage motors, LED drivers and sensitive electronics. Always choose pure sine wave for home use.
How long will an inverter last during load shedding?
Runtime depends on battery bank capacity and your load. A 100Ah 12V lead-acid battery powering 200W will last roughly 4-5 hours. The same Ah in lithium delivers closer to 6-7 hours because you can safely discharge them deeper.
Should I buy a hybrid or standalone inverter?
Buy a hybrid if you can stretch the budget. Even without solar panels now, you can add them later without replacing the inverter. Standalone inverters are a dead-end for solar upgrades.