Solar Proposal Checklist: What a Real Quote Must Show

A solar proposal is a technical and financial document, not a marketing flyer, and the single most useful thing you can do before signing one is check whether it actually contains the information needed to evaluate it. A complete proposal states its assumptions clearly: how production was estimated, what equipment is included, what the warranty actually covers, who handles interconnection with the utility, whether monitoring is included, and what is explicitly excluded. A proposal that skips these details and jumps straight to a price and a payment schedule is not necessarily dishonest, but it is incomplete, and incomplete information is exactly what allows two very different systems to look similar on a one-page summary.

Start with the production estimate, because every other number in the proposal, including any bill savings figure, depends on it. Ask whether the estimate was built from a generic average for your city or from an actual site-specific model using your roof's orientation, tilt, and a documented shade analysis. A credible estimate is shown month by month, not just as a single annual number, so you can compare it against your own monthly usage from electricity bill basics for solar. If the proposal does not disclose the software or method used, or cannot show you how shade or soiling losses were accounted for, ask directly before accepting the number at face value. Sizing should also be justified against your actual annual usage rather than simply filling available roof space; the reasoning covered in sizing your solar system is a useful benchmark for what a properly justified system size looks like.

The equipment list deserves line-by-line attention rather than a single combined price. It should name the specific module make, model, and wattage, and the specific inverter make and model, not a generic category like "400W panel" or "string inverter." Once you have model numbers, you can look up datasheets yourself and compare efficiency, temperature coefficient, and degradation figures across competing quotes, topics covered in solar panel efficiency and solar degradation explained. If the proposal recommends microinverters, string inverters, or optimizers, ask why that architecture fits your specific roof, referencing the trade-offs in microinverters vs string inverters, rather than accepting it as the installer's default package regardless of site conditions.

Warranty language is one of the most commonly glossed-over sections, and it usually contains three separate coverages that a homeowner should not treat as one. Product warranty covers manufacturing defects in the hardware itself. Performance warranty guarantees a minimum output curve over time, typically for modules. Workmanship warranty, provided by the installer rather than the manufacturer, covers installation quality and may or may not include labor for future repairs. A proposal should state all three separately, along with their duration and what triggers a claim; the distinctions and typical terms are covered fully in solar panel warranty guide. Ask specifically what happens if the installer goes out of business: does the manufacturer warranty survive independently, and is there a labor-only cost if a future repair is needed.

Interconnection and permitting scope should be spelled out as clearly as the equipment list. Confirm which party submits the interconnection application to your distribution company, who pays any associated fees, and what happens if the utility requests design changes after review, a process detailed in solar permits and interconnection in Iran. A proposal that simply states "permits included" without naming the specific approvals involved is not giving you enough information to judge whether that line item reflects real scope or is a placeholder. The same applies to the site survey that should precede any serious proposal; compare what your installer actually did against solar site survey checklist to confirm the production estimate was built on a real inspection rather than satellite imagery alone.

Monitoring and post-installation support are easy to overlook when you are focused on the upfront price, but they affect how easily you will notice a problem years into ownership. Ask what monitoring platform is included, whether it is free for the life of the system or requires a subscription after an introductory period, and what data it actually shows: production only, or consumption and export as well. A system without usable monitoring makes it much harder to catch a failing inverter or a new shade source early, a gap that becomes expensive over time.

Exclusions matter as much as inclusions. Ask explicitly whether the quoted price covers any necessary roof repair, electrical panel upgrades if your service capacity is insufficient, structural reinforcement, tree trimming for shade mitigation, or scaffolding and access equipment for difficult roofs. A proposal that is silent on these items is not necessarily hiding costs, but you should assume they are not included unless stated, and get written confirmation before signing rather than discovering a surprise change order mid-project.

Once you have gathered this information from more than one installer, compare proposals using the same categories rather than the same headline price. A slightly more expensive quote with a documented, conservative production model, named equipment with real datasheets, clearly stated warranty terms, defined interconnection scope, and included monitoring is very often the better long-term decision, even against a lower price built on vaguer assumptions. Feed the verified numbers from your strongest proposal into the payback method in solar roi payback method Iran so your final decision rests on your own calculation rather than a number printed on someone else's cover page.

Keep a copy of every proposal you receive, even the ones you decline, along with any written answers to the questions above. If a dispute arises later over what was promised versus what was delivered, a written record of the original assumptions is far more useful than a memory of a sales conversation. Treat the proposal stage as the last point where you have full negotiating leverage: once a contract is signed, correcting a missing detail is harder and often more expensive than asking for it in writing beforehand.