Solar Quotation Checklist: Compare Installer Quotes

A solar quotation checklist should make every installer price comparable against the same requirement. Normalise capacity, exact equipment, design assumptions, installation scope, protection, metering, monitoring, taxes, exclusions, payment, approvals, testing, warranty, service, and handover. Rank price only after each bid passes the technical and responsibility checks.

Two totals are not comparable if one includes a complete commissioned system and the other omits protection, application work, monitoring, taxes, structural work, or customer handover. Use this worksheet to expose those differences before selection.

What should be fixed before requesting solar quotes?

Give every installer the same site and requirement brief before requesting a price. Include electricity data, connection details, site survey, usable roof, shading, structural constraints, target operating mode, backup loads, equipment preferences, approval scope, access conditions, expected deliverables, commercial format, and a deadline for written assumptions and exceptions.

The request should define:

Do not let each installer define a different problem and then compare only totals. Unknown inputs should remain to be verified, with responsibility and price treatment stated.

If export must be limited, use the zero-export inverter comparison to specify the exact control accessory and commissioning evidence every bidder must price.

How should equipment and capacity be normalised?

Compare exact model numbers, quantities, capacity definitions, electrical limits, intended operating mode, and supporting documents in one table. Separate module DC capacity, inverter AC rating, battery power and energy, and backup-load capacity. A larger headline number in one field cannot compensate for incompatibility or missing scope elsewhere.

Reject equivalent model language unless the agreement defines equivalence, evidence, customer approval, price effect, design recheck and document update. Use the inverter-selection scorecard after the technical pass/fail review, not before it.

Which design and installation items should be itemised?

Require the quote to itemise survey, engineering, layout, structure, cabling, connectors, isolation, protection, earthing, metering, communication, access, civil work, installation, labels, testing, commissioning, cleanup, and restoration. Each item needs a specification, quantity or measurement basis, responsible party, acceptance evidence, and stated exclusion where it is absent.

Ask for:

1. site survey and final array layout;
2. structural assessment and mounting specification;
3. DC and AC cable type, size basis, routing and approximate quantity basis;
4. connectors, enclosures, isolators and protective devices;
5. earthing and lightning or surge-protection scope;
6. grid, backup, meter, CT and communication arrangement;
7. scaffolding, lifting, access, waterproofing and roof restoration;
8. shutdown, permit, safety and customer-coordination responsibilities; and
9. labels, test records, as-built drawings and final cleanup.

An inverter or module datasheet does not define the complete installation. Ask the engineer to connect every major component to the approved single-line diagram and acceptance test.

Which application, metering and monitoring items should be clear?

The quote should allocate every application, document, fee, inspection, meter, portal, utility, monitoring, and data-access task. It should say what is included, what depends on an authority, which information the customer supplies, which submission evidence is delivered, and what happens if requirements, capacity, equipment, or timing changes.

Check whether the quote covers:

Do not accept a guaranteed approval or disbursement date from a seller when the authority controls the decision. The net-metering application guide explains what the DISCOM controls and what a seller can promise.

How should taxes, prices, exclusions and changes be compared?

Compare the contracted amount only after identifying taxes, freight, finance, application charges, provisional sums, unit rates, customer-supplied work, exclusions, validity, escalation, substitutions, and change-order rules. The quote should state what triggers extra cost, who approves it, how the amount is calculated, and whether work can proceed before written approval.

Use a commercial reconciliation:

Do not compute or publish a result when excluded quantities and rates are unknown. Instead, mark the bid commercially incomplete.

Keep government assistance, export credit, bill savings, and financing separate from the seller’s contract price. If an installer uses them to show a net cost, require both the full payable amount and the dated source and eligibility assumptions for each offset.

How should warranty, service and maintenance be compared?

Separate manufacturer product warranties from installer design, workmanship, application, commissioning, monitoring, maintenance, and service duties. Compare covered events, exclusions, remedy, parts, labour, freight, removal, reinstallation, response process, evidence, escalation, duration, transfer, and the responsible organisation. A headline number of years does not answer those questions.

Request the actual warranty documents before payment. Ask which tasks the owner must perform, who is authorised to open equipment, and how an unresolved fault is escalated. Any paid maintenance or monitoring agreement should identify scope, visit or condition triggers, reports, exclusions, parts, travel, renewal and termination.

Use the solar inverter warranty guide and installation-versus-product warranty guide to keep the obligations separate.

What payment and schedule terms should be reviewed?

Tie payment milestones to objective deliverables, inspection rights, documents, title and risk where applicable, and a correction process. The schedule should identify dependencies, customer actions, authority decisions, access, force majeure or delay treatment, storage, substitutions, change orders, suspension, cancellation, refund, retention, and completion evidence without promising a universal timeline.

Example milestone questions:

• What document or physical result makes the milestone due?
• Can the customer verify model numbers and quantity before payment?
• When do title and risk pass for equipment delivered to site?
• What happens if the authority, survey or final design changes capacity or scope?
• How are damaged, delayed, rejected or substituted items handled?
• Which defects or missing handover documents prevent completion?
• What balance remains until testing, commissioning and handover are complete?

Obtain legal and financial review for material contract terms. A percentage sequence copied from another project is not a substitute for risk allocation on this one.

What must be tested and handed over?

The quote should define commissioning tests, acceptance criteria, witnessed operating scenarios, authority records, as-built documents, monitoring access, owner instruction, warranties, service contacts, and open-item closure. The handover pack must identify the installed models, serial numbers, settings and results so a later technician can reconstruct the approved system.

Use the solar inverter commissioning guide to develop the project checklist. At minimum, require the approved and as-built single-line diagrams, array and protection details, equipment schedule, serial register, settings record, test results, inspection documents, monitoring ownership, warranty documents, invoice, maintenance instructions and unresolved-item log.

What is the final quote-comparison decision rule?

First reject or hold bids with unresolved safety, compliance, compatibility, approval, scope, responsibility, or evidence gaps. Then normalise the remaining bids commercially and compare supported preferences such as service, schedule, monitoring, warranty, and price. Document the selection, conditions, open items, and who approved every exception.

Final review sequence:

1. Confirm every bidder answered the same requirement.
2. Complete the exact-model and design pass/fail review.
3. Reconcile included, excluded and provisional scope.
4. Check application, authority and customer dependencies.
5. Compare warranty, service, payment, change and handover terms.
6. Price required gaps only with supported quantities and rates.
7. Record technical, commercial, financial and legal reviews.
8. Carry agreed clarifications into the signed contract and schedules.

Qbits is an inverter manufacturer and does not install systems or issue installation quotes. Use the completed comparison table with your chosen installer; if a quote names a Qbits inverter and you have questions about the model, contact Qbits. Installers can apply through become our partner, and owners can find service through the authorised service partners. Confirm engineering, tax, legal and commercial terms for your own project before relying on this template.

Sources checked 23 September 2026: current Qbits datasheets, inverter-selection, warranty, installation-warranty, commissioning and net-metering guides. No claim is made that a generic inclusion, tax treatment, payment milestone, price or service term applies to every project.