When homeowners start comparing solar panel quotes, the first instinct is to look at the bottom line. But unlike many home improvements, solar quotes are rarely like-for-like — even when they appear to use similar equipment.
At Quantum Electrical Services, we regularly speak to customers who are confused by wildly different prices for what seems like “the same system”. In reality, the differences are often hidden in the design.
What Most Solar Quotes Don’t Show You
A solar quote typically lists panels, an inverter, and an install price. What it often doesn’t explain is:
How the panels are configured electrically
Whether shading has been properly modelled
If the inverter is correctly sized
How future batteries or EV chargers will integrate
Whether performance assumptions are realistic
Two systems can use the same hardware and still produce very different results over 25 years.
Design vs Product Pricing
Solar performance is driven by system design, not just components.
Key design differences that affect output include:
String layout across roof faces
Panel grouping and voltage balancing
Shading mitigation strategy
Cable routing and voltage drop
Monitoring setup and commissioning quality
These factors rarely show up clearly on a quote — but they directly affect how much energy your system produces.
Why the Cheapest Quote Often Underperforms
Lower-priced quotes often rely on:
Generic system layouts
Minimal site assessment
No allowance for future upgrades
Optimistic generation estimates
The system may “work”, but quietly underperform year after year.
Over time, that lost generation can outweigh the initial saving.
What to Compare Instead of Price Alone
When reviewing solar quotes, focus on:
Expected annual generation (and how it’s calculated)
How shading is addressed
Whether the system is future-ready
Who will support the system long-term
A well-designed system should still make sense five, ten, and twenty years from now.
