This article is to help you compare solar installation proposals. I encourage people to get at least two bids, and to avoid any financing not fully understand.

Note on terms: Bids, quotes, proposals… all the same to me. We are talking about the contract a solar installer is proposing.

As a former solar installer, seller, researcher, and site-planner I would look at any solar installation quote with an eye to the following considerations.

Considerations for homeowners seeking solar bids:

  Consideration What to ask your installer What to look for
1 Price per installed kilowatt Is the price on your bid showing a pre-incentive price? Or a post-incentive price? Both are fine, but be sure to know which you are comparing.
2 Convenience & Installation Schedule When does work start and finish? Who handles permits and utility interconnection? Typically the installer handles the building permits, and assists the homeowner to apply for utility interconnection.
3 Risks What does the contract actually say about warranties, cancellation, and financing? The financing should be easy to understand.

Price of the system (per installed kilowatt)

The most important thing to understand for comparing bids is price in terms of $/installed kilowatt. The system designs may vary from different installers, which is fine. The way to handle that difference as a buyer is to compare price per installed kilowatt. Let the installer worry about factoring in the cost of trenching, or navigating your funky roof. Your job is to understand installed kilowatt price: total contract price/system size in kW.

The installed kilowatt price bundles everything required to get the system producing power:

  • Modules (panels).
  • Inverter(s) — converts DC from panels to AC your home uses. Could be a string inverter, microinverters, or power optimizers.
    • My opinion is that people should go with microinverters, unless the site has absolutely ZERO shade.
  • Racking & mounting hardware. {roof attachments, rails, clamps}
  • Wiring, conduit, disconnects, breakers.
  • Labor {installation crew, site survey crew, system design, structural engineering, electricians}.
  • Permitting fees.
  • Utility interconnection fees.
  • Installer overhead & margin.

Terms:

  • Pre-incentive price — compare raw system cost before federal tax credit (ITC), state rebates, or utility incentives.
  • System size (kW) — confirm you’re comparing similarly sized systems. A cheaper quote may simply be a smaller system.
  • Equipment tier — premium panels and inverters cost more but affect long-term yield and warranty coverage.

Premium panels compared to economy panels

My take is that both are great, and the panel that pays for itself best is the one pointed directly at the sun. Premium panels will usually have less of a gradual decline in performance, and be more space efficient. Economy panels may pay for themselves faster. shrugs Either choice is fine.

Convenience & Installation Schedule

What the installer typically handles:

  • Pulling building permits with the city or county.
  • Scheduling the physical installation crew.
  • Submitting interconnection paperwork with Idaho Power.

What the homeowners, typically handle:

  • Signing the utility interconnection agreement.
  • Being available for the utility’s final inspection.
  • Monitoring system activation (some installers help; many don’t).

Timeline to expect in the Treasure Valley:

Phase Typical Duration Notes
Contract to permit approval 2–6 weeks Ada County and Boise City are generally straightforward
Physical installation 1–2 days Most residential systems go up in a single day
Utility interconnection 2–8 weeks Idaho Power’s queue varies by season
Permission to Operate (PTO) Same day as inspection You cannot legally turn on the system until PTO is granted

Boise note: Idaho Power is your utility if you’re in most of the Treasure Valley. They have an interconnection process that is generally smooth, but can slow down in spring when many installers submit at once.

What to compare timeline-wise across bids:

  • Does the installer give you a projected timeline in writing?
  • Do they handle all permit submissions, or do they hand that off to you?
  • Is there a clause about delays — who is responsible if the project drags past a promised date?
  • Is the installation crew in-house, or subcontracted? (Subcontracted crews can mean less accountability if something goes wrong).

Risks

Most solar installations go smoothly. But knowing where things can go wrong is probably wise. There are a few good companies in the Treasure Valley. I would prefer a warranty from a more seasoned company, with offices within 100 miles.

Roof condition Solar panels are warrantied for around 25 years. If your roof needs work in year 8, you’re paying to remove and reinstall the panels. Ask your installer to assess your roof age and condition honestly before signing. If they don’t mention it, ask.

Fun trick: If a solar installer diagnosis a roof replacement as neccessary for installation, you may be eligible for tax credits to help pay for the roof repair.

Shading changes over time Trees grow. A system designed around today’s shading may underperform in 10 years. Ask if the site assessment accounted for tree growth, and whether microinverters or power optimizers were specified for that reason.

Production estimates Every proposal includes a first-year production estimate (in kWh). These are projections, not guarantees. Ask what assumptions were made — tilt, azimuth, shading factor, degradation rate. A suspiciously high estimate is a sales tool.

Warranty coverage gaps There are typically three separate warranties:

  • Panel manufacturer warranty — usually 25 years on performance, 10–12 years on product defects.
  • Inverter warranty — 10–25 years depending on brand and type.
  • Installer workmanship warranty — covers roof penetrations, wiring, mounting. Often only 5–10 years, and only as good as the company backing it.

If the installer goes out of business, the workmanship warranty goes with them.

How long has the installer been around so far?


Good luck with your solar panels!
Thomas Lansing