Solar Sizing in Cape Town: How to Get the Right kVA
A solar system that's too small wastes capital on something that fails to cover load-shedding; too big and you bank capacity you never use. A practical sizing guide for Cape Town homes.
Cape Town's solar market has matured fast — most installers can spec a system in their sleep. But "spec" varies wildly: a R140,000 quote and a R220,000 quote for the same brief usually differ on inverter brand, battery chemistry and panel count, not just margin.
Start with your actual usage
Pull your last 3 months of City of Cape Town electricity bills. The kWh-per-day figure is the only honest input to sizing. A typical 3-bed CT home runs 18-30 kWh/day; a household with electric geyser, 2-3 aircons and a pool pump runs 35-60 kWh/day.
What to size for
- Backup-only system — covers essentials during load-shedding (lights, fridge, Wi-Fi, charging). 5kVA inverter, 5-7 kWh battery: R75,000-R110,000.
- Hybrid grid-tie — runs from solar by day, battery at night, grid as fallback. 8kVA inverter, 10kWh battery, 6-10 panels: R130,000-R200,000.
- Higher-capacity hybrid — covers a bigger household plus pool. 12kVA inverter, 15-20 kWh battery, 16+ panels: R220,000-R360,000.
What separates good installers
- PVGreenCard/SAPVIA membership
- Detailed equipment list with model numbers (Sunsynk vs Deye vs Victron — known brands have known support)
- LiFePO4 battery (not lead-acid) with 10-year manufacturer warranty
- City of Cape Town SSEG approval handling — they file the paperwork
- Monitoring app that actually works for the long term
Browse Cape Town solar installers on Handi-za, share your last 3 months of usage, and you'll get sized, costed quotes back fast.
Frequently asked questions
Do I need to register my solar system with the City of Cape Town?
Yes — any grid-tied solar system needs a Small-Scale Embedded Generation (SSEG) application. Most reputable installers handle the paperwork. Without registration you can be fined and your insurance may not cover system damage.
How long do solar panels last?
Tier-1 panels (Canadian Solar, JA, JinkoSolar, Longi) carry a 25-year linear performance warranty — they'll still produce ~85% of their original output at year 25. Inverters last 8-15 years; batteries 10-15 years for LiFePO4.
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