Path-Q Solar

What should I do if a solar installer will not provide a detailed production estimate?

Answer

Ask once in writing for the production estimate, monthly output, modeling assumptions, and system design needed to evaluate it. If the installer still refuses or provides only a vague savings claim, treat that as a comparison and transparency concern and seek another proposal.

Key points

  • Request expected annual and monthly production rather than only bill savings or payback.
  • Ask for system size, layout, shading assumptions, loss factors, weather data basis, and degradation treatment.
  • Clarify whether the figure is modeled production, a guarantee, or a sales projection.
  • Compare the estimate with independent modeling or other proposals using consistent assumptions.
  • Do not accept a production guarantee unless its measurement method, exclusions, remedy, and duration are written clearly.

What it depends on

  • The installer's modeling process and willingness to disclose assumptions
  • The complexity of the site and system
  • Your ability to compare proposals
  • The contract's treatment of production and remedies

Risks and trade-offs

  • Without production detail, you cannot fairly assess system size, value, or underperformance.
  • Savings depend on electricity use and billing terms, not production alone.
  • A detailed estimate is not proof of accuracy if its assumptions are optimistic or unsupported.

Information you may need

  • Proposed system size and layout
  • Monthly and annual production estimate
  • Weather, shading, and loss assumptions
  • Any written production commitment and remedy

Your next step

What to do next

Send a written request for a complete production model; if it is not provided before contract signing, pause the decision and obtain a comparable proposal from another installer.

Path-Q

Find the right next step

Answer a few questions and we’ll narrow your options.

Loading…

SQ00428