☀️ Always On Energy Solar system client education series Post 1 :

Planning for Off-Grid Solar in a Failing Grid Environment

Audience: Residential and small business owners within 60–80km of Cresta MallPurpose: Equip clients to design scalable solar systems that anticipate Eskom’s decline and prepare for full energy independence, for sustainability and security during no power.

📘 Post 1:  First step.

Designing for 100% Sunlight Days (Winter Benchmark)

🔧 Assumptions:

• Winter is the peak consumption season due to heating and longer nights.

• Average daily usage: 25 kWh/day (adjustable per client)

• Solar generation window: ~4.8 hours/day

• Night-time load: 0.51 kW/hour × (24-4.8)19.2 hours = 9.79 kWh battery need

• Assuming Battery Dod C-rate: 0.7C → Must sustain 0.51 kW for 19.2 hours

🔋 Battery Sizing:

Parameter	Value
Load during non-solar hours	0.51 kW × 19.2 hrs = 9.79 kWh
C-rate (DOD)	0.7C
Recommended Battery	~13–14 kWh (nominal, assuming 70% DoD)

☀️ PV Sizing:

• Winter irradiance in Johannesburg: ~4.8 kWh/day per kW installed

• To generate 25 kWh/day:

  • Required PV = 25 ÷ 4.8 ≈ 5.2 kW

    
    

Post 2 will follow in the next Post from Always On Energy to look at a 50% Solar day.