Comparing quotes for solar panels

You request three quotes and the amounts are close together. Yet there can be a world of difference between them. What one quote simply includes appears in another as extra work, or is not mentioned at all. These points help you compare like with like.

1. Look at capacity, not the number of panels

Twelve panels means nothing without the watt-peak capacity. Compare the total capacity in Wp and, more importantly, the expected annual yield in kWh for your specific roof. A quote that does not mention that calculation is incomplete.

2. Ask about the inverter

A single central inverter is cheaper, but with shade or several roof surfaces it costs yield. Micro-inverters cost more to buy and give insight and output per panel. If the quote only says "inverter", ask for the brand, type and warranty period.

• Compare Wp and expected kWh per year
• Ask the brand and type of inverter
• Check what is not included
• Four different warranty terms

3. Watch what is not in there

Is the mounting structure included? The cabling and the roof penetration? Registration with the grid operator? Tidying the cables away inside? And who is responsible if a roof tile breaks? A complete quote answers those questions without you having to ask.

4. Warranty is not a single number

There is product warranty on the panels, performance warranty on the yield after fifteen or twenty years, warranty on the inverter and warranty on the installation work itself. Those four terms differ. Ask for all four and you know where you stand.

In practice this subject belongs with sales and installation and led lighting. There you can read how we work and what is possible, or you can request a no-obligation quote straight away.

Further reading: heat pumps in Kaatsheuvel, what does advice and design cost?, what does sales and installation cost?.

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