The Short Answer
If you own your home and can afford R85,000+ upfront (or solar finance), solar is cheaper long-term. It pays for itself in 3-7 years, then saves you money for the next 20+ years.
If you rent, need backup this week, or have less than R10,000 to spend, a generator is the practical choice — just know that it will cost you R2,000-R5,000/month in fuel during heavy load shedding.
Cost Comparison: Real Numbers
Let's compare a 5kW solar system vs a 5kVA petrol generator for a typical Gauteng home with a R2,500/month Eskom bill, experiencing Stage 4 load shedding (8 hours/day, 20 days/month):
Solar (5kW System)
- Upfront: R85,000 — R130,000 (panels + inverter + mounting + installation)
- With battery (5kWh): Add R25,000 — R45,000
- Monthly running cost: R0
- Monthly Eskom saving: R1,500
- Payback period: 4-7 years
- 25-year total saving: R1.2M — R2M (assuming 12% annual Eskom increases)
Generator (5kVA Petrol)
- Upfront: R10,000 — R22,000
- Monthly fuel (Stage 4): R2,500 — R5,500
- Monthly maintenance: R300
- Monthly Eskom saving: R0 (generator doesn't reduce your Eskom bill)
- 5-year total cost: R178,000 — R374,000
- 10-year total cost: R346,000 — R726,000 (including one generator replacement)
Beyond Cost: Other Factors
Noise
Generators produce 68-80 dB — about as loud as a vacuum cleaner running constantly. If you live in a complex, sectional title, or have close neighbours, this is a real problem. Many body corporates now restrict generator use. Solar is completely silent.
Maintenance
Generators need oil changes every 50-100 hours, spark plug replacements, air filter cleaning, and fuel filter changes. During heavy load shedding, that's a service every 1-2 months. Solar panels need cleaning 2-3 times per year — that's it.
Reliability
Generators have moving parts that wear out. A petrol generator typically lasts 5,000-10,000 hours — at Stage 4 load shedding, that's 3-6 years before replacement. Solar panels are warrantied for 25 years and typically produce power for 30+.
Property Value
Solar installations increase property value by 3-5% according to multiple international studies. Generators have near-zero resale value after a few years.
Environment
A 5kVA generator running 8 hours/day produces approximately 15-20 kg of CO2 per day. Over a year of Stage 4 load shedding, that's 3-4 tonnes of CO2 — plus noise pollution and local air quality impact. Solar produces zero emissions.
The Hybrid Option
Some homeowners combine both: solar for daily savings and daytime backup, plus a small generator (2-3kVA) as a fallback for extended outages or nighttime load shedding before they add battery storage. This gives the best of both worlds but at a higher total cost.
What About Inverters + Batteries (No Solar)?
An inverter + battery system (R15,000-R80,000) stores Eskom power when the grid is on and releases it during load shedding. It's simpler than solar and cheaper upfront than a full solar system. The downside: it doesn't reduce your Eskom bill — you're still paying Eskom for the power you store. Think of it as a silent, maintenance-free generator that runs on electricity instead of fuel.
Decision Framework
Ask yourself these 5 questions:
- Do I own my home? If no → generator or inverter+battery
- Can I afford R80K+ upfront (or solar finance)? If no → generator or inverter+battery
- Will I stay in this property 3+ years? If no → generator
- Do noise and fumes matter? If yes → solar or inverter+battery
- Do I want to reduce my Eskom bill permanently? If yes → solar is the only option
Solar Finance Options
Can't afford the upfront cost? Several SA providers offer solar finance:
- GoSolr: Monthly subscription from R1,299/month. No upfront cost. They own and maintain the system.
- Nedbank MFC: Asset finance up to 96 months. Competitive rates.
- Standard Bank: Energy Loan up to R300,000 with government guarantee.
- FNB: Solar loan via home loan, discounted rate.
- ooba Solar: Multi-lender originator (like a solar mortgage broker).
With finance, your monthly repayment is often less than what you save on Eskom — meaning solar can be cash-flow positive from month 1.