27/05/2026
*Before You Install Solar, Understand Your Power First*
A client called me frustrated one evening.
“Mr Ndou,” they said, “I spent a lot on solar, but I’m still rationing power like before. What did I actually pay for?”
I asked one question:
“Did anyone analyze your daily power usage before designing the system?”
They went quiet. That’s usually the problem.
Solar is a System, Not Just Hardware
Most people think solar means buying panels, an inverter, and a battery. That’s only half the story.
Solar works when *generation, storage, and consumption are balanced*. If you don’t know how much energy you use and when you use it, even a R100k system will disappoint you.
The Main Reason Systems Fail
Systems are usually sized based on:
- Budget constraints
- What a neighbor or friend has
- Marketing claims online
- *“My friend has a 5kVA system”*
They should be sized based on:
- *Actual load profile*: What devices run, and for how long
- *Peak demand*: The highest power draw at any moment
- *Autonomy required*: How many hours you need backup without sun
- *Day vs night usage split*: Solar charges in the day, but most homes use power at night
Not All Loads Are Equal
A 100W LED light and a 100W fridge are not the same.
Motors, compressors, and pumps have *high startup currents* that can be 3-7x their running wattage. If your inverter and battery aren’t sized for those surges, the system will shut down.
Batteries Have Limits
A battery doesn’t store “unlimited” power.
If you draw 2kWh per night but your panels only recharge 1.5kWh per day, you’ll deplete the battery daily. That kills lifespan fast.
Key battery rules:
- *Lead-acid*: Keep depth of discharge above 50% for decent lifespan
- *LiFePO4/Lithium*: Can go to 80-90% DOD, lasts 3000-6000 cycles
- *C-Rate matters*: A 100Ah battery discharged at 1C gives 100A for 1hr. Discharge faster and you lose usable capacity
Sun Isn’t Constant
Solar panels are rated at Standard Test Conditions – 1000W/m² irradian
