What Does “System Size” Mean?
System size is the total DC power of all panels combined.
Formula:
System Size (kW) = Number of Panels × Panel Wattage ÷ 1000
Example:
10 panels × 400W = 4,000W = 4.0 kW system
Step-by-Step: How to Size a System (Sales Method)
STEP 1: Understand the Goal
- Reduce bill?
- Offset 70–90%?
- Add battery backup?
- EV now or later?
💬 Sales Script:
“We’re not guessing — we design the system around how you actually use power.”
STEP 2: Estimate Required System Size
- Small home: ~4.0–4.5 kW
- Medium home: ~4.8–5.6 kW
- Larger home: ~6.0 kW+
STEP 3: Convert kW → Panels
Panels = (System Size × 1000) ÷ Panel Wattage
Example:
5.6 kW system with 400W panels
→ (5,600 ÷ 400) = 14 panels
Knowledge Check
If a medium home needs ~5.6 kW and panels are 400W each, how many panels are required?