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Questions to ask solar installers

Use a disciplined question list before you sign or pay a reservation fee.

Part of the: Choose and compare solar installers

SolarGabay Editorial Sources reviewed Updated July 20, 2026 · 13 min

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SolarGabay Editorial Team — independent consumer-focused writers who translate technical sources into practical homeowner guidance.

Technical review

Reviewed against the published methodology, source hierarchy, and stated limitations. This is educational guidance, not site-specific engineering.

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Last reviewed July 20, 2026. Corrections are logged through the public corrections process and material changes update this date.

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Practical answer

What you should know first

The right questions help you separate a careful installer from a fast-selling one. Your goal is not to sound technical. Your goal is to make sure the installer can explain the design, the risks, and the support process clearly.

The best questions test whether the installer understands your property and will remain accountable after commissioning.

Decision map

Ask questions that require evidence

Show me

Roof layout, shade study, model numbers, calculations, and protection diagram.

Explain why

System size, inverter choice, battery runtime, and expected generation.

Who is responsible

Permits, roof leaks, utility approval, faults, warranties, and replacement labor.

The variables that matter

Strong installers explain assumptions instead of hiding behind jargon.

Good answers include documents, not just verbal reassurance.

Support questions matter because the system will need attention long after installation day.

Honest installers will admit uncertainty where site inspection or utility confirmation is still required.

Questions about the design

Ask which bills and measurements were used, how shading was assessed, why the inverter and panel count were selected, what annual production is expected, and which assumptions have not yet been verified.

For backup systems, ask for the supported circuits, continuous power, surge power, usable battery capacity, reserve setting, and behavior when the battery is depleted.

Roofing crew completing installation work that should be defined in a solar quotation — Strong questions force an installer to connect sales claims to the roof, electrical design, production model, outage behavior, warranty, and service plan.

What could change after the site inspection?

How was the production estimate calculated?

Which electrical and roof upgrades are included?

[1] U.S. Department of Energy [2] U.S. Department of Energy

Questions about the company and support

DOE guidance recommends checking credentials, experience, subcontractors, warranties, and references. Add practical service questions: who answers monitoring alerts, who carries replacement stock, and what labor is charged during a manufacturer warranty claim.

A credible installer should be comfortable explaining limitations. Ask what conditions would make them recommend delaying or reducing the project.

Who signs the design and who supervises installation?

What is the fault-response process after handover?

Can the company provide recent references for similar projects?

[1] U.S. Department of Energy [2] U.S. Department of Energy

Worked example

Replace “Is the warranty good?” with a traceable question

Ask who files the claim, who removes and reinstalls the equipment, whether labor and transport are covered, how long response normally takes, and what happens if the installer closes.

Specific questions produce usable commitments.

Decision rule

Prefer the installer that answers with documents, calculations, and named responsibilities instead of reassurance alone.

Practical checklist

Ask what system assumptions could still change after a site visit.

Ask who handles warranty claims and how response times are managed.

Ask how monitoring alerts, underperformance, and faults are handled post-installation.

Ask what would make them tell you not to install solar yet.

Evidence, scope and limitations

A serious installer should be comfortable with serious questions.

International references are used for engineering and consumer principles. Philippine utility procedures, tariffs, permits and legal requirements must be confirmed using current local rules.

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