12 Questions to Ask Before You Buy a Solar System

A solar system is a long-term purchase. Most problems that appear after installation can be traced back to questions that were not asked at the start. Use these twelve as a checklist when you talk to installers and compare quotations.

Key takeaways

• Ask for brands and model numbers, not just "branded" equipment.
• A design drawing and a site visit should come before the final price.
• Warranty terms, who services the system and how fast matter as much as the price.
• Written answers are better than promises.

1. About the equipment

1. Which brand and model are the panels, inverter, batteries and mounting structure?
2. Are the panels and inverter supplied with manufacturer warranties, and for how many years?
3. What are the efficiency and the temperature coefficient of the panels?

Our guides on solar panel types and the solar inverter guide explain what these mean.

2. About the design

1. Was the roof visited and measured, and was shade checked?
2. How many kilowatts of panels and what size of inverter, and why?
3. Is there a drawing showing the layout, the strings and the connections?
4. What protection is included: DC isolator, breakers, surge protection, earthing?

3. About installation and approvals

1. Who will install it: the company's own team or a sub-contractor?
2. Who deals with the electricity company for net metering, and what does it cost?
3. How long will the installation take, and what is the payment schedule?

4. About service

1. Who services the system after installation, and how quickly can they come?
2. What is covered under the warranty and what is not, for example cleaning, travel or labour?

What a good answer sounds like

A good installer answers with specifics: model numbers, a drawing, a written warranty and a named contact. Be cautious of vague words such as "best quality" or of a price that is far below others without a clear reason. For a longer look at price, read what decides solar system cost.

Next step

Take this list to every installer you meet. If you would like our answers in writing, request a quotation through the quotation form.