What Should Be Included in a Professional Solar Quotation and BOQ?

A professional solar quotation should tell you much more than the system size and total price.

If one proposal says “10kW solar system” with a final amount and another provides equipment models, quantities, electrical protections, structure specifications, warranties, installation scope and expected performance, the two quotations are not equally informative.

This is where a BOQ becomes important.

BOQ stands for Bill of Quantities. In a solar project, it should clearly identify the equipment, materials, quantities and major work included in the proposed system.

A detailed quotation and BOQ help the customer understand what is actually being purchased and make it easier to compare competing proposals fairly.

What Is the Difference Between a Solar Quotation and BOQ?

A solar quotation is the commercial proposal for the project.

It normally includes:

• Proposed system capacity.

• Project scope.

• Equipment.

• Price.

• Payment terms.

• Timeline.

• Warranties.

• Commercial conditions.

The BOQ provides a more detailed breakdown of the equipment and materials.

For example, instead of writing only:

“Solar panels included”

a proper BOQ may specify:

• Manufacturer.

• Module model.

• Wattage.

• Quantity.

• Total DC capacity.

The quotation explains the overall offer, while the BOQ explains what is physically included in that offer.

System Capacity Should Be Clearly Defined

The quotation should clearly state the proposed solar capacity.

Do not accept vague wording such as:

“Approximately 10kW system.”

The proposal should distinguish between relevant capacities where necessary, particularly:

• Solar-array DC capacity.

• Inverter AC capacity.

• Battery capacity for hybrid or off-grid systems.

For example, a project may have a solar-array capacity slightly different from the inverter's nominal AC rating.

That does not automatically indicate a problem, but the design should be clear enough for the customer to understand what is being supplied.

The Solar Panel Specification Should Be Exact

The quotation should not simply say:

“Tier-1 solar panels.”

It should identify the proposed module as accurately as possible.

Important information includes:

• Manufacturer.

• Model or series.

• Cell technology.

• Module wattage.

• Number of panels.

• Total array capacity.

• Module efficiency where relevant.

• Product warranty.

• Performance warranty.

This is particularly important when comparing N-Type TOPCon, PERC or bifacial modules.

Two quotations offering the same number of panels may contain very different equipment.

Our guide to N-Type TOPCon, Mono PERC and bifacial solar panels explains the main technology differences.

The Inverter Must Be Fully Specified

The inverter is central to the performance and functionality of the solar system.

The BOQ should state:

• Manufacturer.

• Exact model.

• Inverter rating.

• Single-phase or three-phase configuration.

• On-grid, hybrid or off-grid architecture.

• Quantity.

• Warranty.

For hybrid systems, battery compatibility and backup capability should also be understood.

A quotation that says only “10kW hybrid inverter” leaves too much information unanswered.

Our solar inverter selection guide explains why MPPT limits, PV input specifications, backup output and battery compatibility matter.

Battery Storage Needs More Than a Brand Name

If batteries are included, the quotation should identify:

• Battery manufacturer.

• Model.

• Battery chemistry.

• Nominal capacity.

• Usable capacity where specified.

• Quantity.

• System voltage.

• Warranty.

The quotation should also explain what the proposed storage is intended to achieve.

For example:

• Essential-load backup.

• Whole-home backup.

• Evening energy shifting.

• Off-grid operation.

A battery should not be sold only as:

“10kW battery.”

Battery energy is normally discussed in kWh, while power capability is expressed in kW.

Our battery-sizing guide explains how backup load and duration should determine the required storage.

Mounting Structure Should Be Included in the BOQ

The structure holding the solar panels is part of the system, not an optional detail.

A professional quotation should describe the proposed mounting arrangement.

Depending on the project, this may include:

• Rooftop mounting structure.

• Elevated structure.

• Ground-mounted structure.

• Solar carport.

• Customized fabricated structure.

Useful details can include:

• Material type.

• Galvanization or corrosion protection.

• Proposed tilt.

• Structural design assumptions.

• Installation method.

For larger or unusual installations, structural suitability should be evaluated rather than assuming every rooftop can support the same arrangement.

Electrical Protection Should Be Clearly Listed

Electrical protections should not be hidden under a vague line such as:

“Complete electrical accessories.”

A professional solar BOQ may identify items such as:

• DC isolators.

• AC isolators.

• DC circuit protection.

• AC circuit protection.

• Surge protection devices.

• Distribution boxes.

• Earthing equipment.

• Appropriate breakers.

• Protection enclosures.

The exact protection design depends on system architecture and electrical requirements.

Customers should know that safety equipment is included rather than discovering later that important items were treated as additional cost.

Cables and Connectors Matter

Solar systems operate for many years, so cable quality matters.

The BOQ should distinguish relevant solar and AC cabling where appropriate.

Important considerations may include:

• Solar DC cable.

• AC power cable.

• Cable size.

• Cable route.

• Connectors.

• Conduits or cable trays.

• Required terminations.

Cable sizing should reflect current, voltage, distance and installation conditions.

Using high-quality panels and inverters does not compensate for poor electrical installation.

Expected Solar Generation Should Explain Its Assumptions

A quotation may include estimated monthly or annual electricity generation.

That can be useful, but the number should not appear as a guaranteed result without context.

Expected production can be affected by:

• Location.

• Panel orientation.

• Tilt.

• Shading.

• Temperature.

• Dust.

• Equipment efficiency.

• System losses.

• Weather variation.

A professional proposal should distinguish an engineering estimate from a guaranteed electricity figure.

Customers should also ask what assumptions were used to produce the forecast.

The Quotation Should Explain the System Architecture

The proposal should clearly identify whether the project is:

• On-grid.

• Hybrid.

• Off-grid.

The system type changes how the inverter, batteries, grid connection and backup loads operate.

For hybrid projects, the quotation should also clarify which loads are expected to receive backup power.

Do not assume the term “hybrid” means the entire property will remain operational during an outage.

Our comparison of on-grid, hybrid and off-grid systems explains these differences.

Grid-Connection and Approval Scope Should Be Clear

For grid-connected projects, the quotation should clarify which approval-related services are included.

Possible scope may include:

• Application preparation.

• Required documentation.

• Interconnection coordination.

• Metering-related support.

• Technical submissions.

• Applicable regulatory processing.

The proposal should also identify any government, utility or regulatory fees that are included or excluded.

This prevents disagreement later about who is responsible for the approval process or additional charges.

Installation Scope Should Be Written Down

“Installation included” can still be too vague.

The quotation should define the expected scope, such as:

• Site survey.

• Engineering design.

• Equipment delivery.

• Mounting structure installation.

• Solar-panel installation.

• Inverter installation.

• Battery installation where applicable.

• Electrical wiring.

• Protection equipment.

• Earthing.

• Testing.

• Commissioning.

• System handover.

For commercial projects, documentation, monitoring configuration and operator training may also be relevant.

Warranties Should Be Separated

Not all solar warranties are the same.

The quotation should distinguish between:

• Solar-panel product warranty.

• Solar-panel performance warranty.

• Inverter warranty.

• Battery warranty.

• Installation or workmanship warranty.

• Structure warranty where applicable.

It should also be clear whether warranty support is provided directly through the installer, distributor or manufacturer.

Do not treat one long panel performance warranty as though it covers every component in the system.

Project Timeline Should Be Realistic

A professional quotation should give the customer an expected project schedule.

The timeline may include:

• Equipment procurement.

• Site preparation.

• Installation.

• Testing.

• Commissioning.

• Grid-related processing where applicable.

External approvals can sometimes affect the final completion date, so the proposal should distinguish installer-controlled work from timelines dependent on third parties.

Payment Terms Must Be Clear

The quotation should explain when payments are due.

For example, the commercial structure may involve:

• Advance payment.

• Equipment-delivery milestone.

• Installation milestone.

• Final payment after commissioning.

The exact arrangement varies by project.

What matters is that payment terms are written clearly before work begins.

Check What Is Excluded

Exclusions can be just as important as inclusions.

A quotation should identify significant work that is not covered.

Possible exclusions may include:

• Major civil work.

• Roof strengthening.

• Utility fees.

• New transformer requirements.

• Significant electrical-panel upgrades.

• Long-distance cable work.

• Generator integration.

• Additional battery backup.

• Internet connection for monitoring.

A low quotation can become expensive later if essential work was simply left outside the original scope.

How to Compare Two Solar Quotations Properly

Do not compare only the final price.

Compare quotations line by line:

1. Solar DC capacity.

2. Panel manufacturer and model.

3. Inverter manufacturer and model.

4. Battery specifications.

5. Structure.

6. Electrical protections.

7. Cabling.

8. Monitoring.

9. Installation scope.

10. Approval support.

11. Warranties.

12. Estimated production.

13. Payment terms.

14. Timeline.

15. Exclusions.

If one proposal is cheaper, identify exactly what is different.

The lowest total price is not necessarily the lowest-value project, and the highest price does not automatically mean better engineering.

Red Flags in a Solar Quotation

Be cautious if a quotation:

• Lists no exact equipment models.

• Provides no panel quantities.

• Does not separate inverter and solar capacity.

• Promises unrealistic electricity production.

• Leaves batteries poorly defined.

• Does not list electrical protection.

• Has no warranty information.

• Hides exclusions.

• Provides no installation scope.

• Recommends capacity without reviewing electricity consumption.

A professional quotation should make the project easier to understand, not harder.

A Good Solar BOQ Protects Both Customer and Installer

A detailed BOQ reduces ambiguity.

The customer knows what equipment and services are being purchased.

The installer has a documented scope against which procurement and execution can be managed.

For residential installations, this improves transparency.

For commercial and industrial projects, a clear BOQ becomes even more important because equipment quantities, structures, electrical works and commissioning requirements can be substantially more complex.

E&E Industries provides engineering-led solar EPC services covering assessment, design, procurement, installation, testing and commissioning for residential, commercial, industrial and agricultural projects.

Before approving a quotation, make sure the proposed system is technically defined rather than represented only by a kW size and total price.

Frequently Asked Questions

What does BOQ mean in a solar quotation?

BOQ means Bill of Quantities. It provides a detailed breakdown of the equipment, materials and quantities included in the proposed solar project.

Should a solar quotation include exact panel and inverter models?

Yes. Exact models make it easier to verify specifications, warranties and whether competing quotations contain comparable equipment.

Should electrical protection be listed separately?

A professional BOQ should clearly identify the major protection equipment included rather than hiding everything under a generic accessories line.

Should estimated solar generation be guaranteed?

Solar generation should normally be presented as an estimate based on stated assumptions because weather, temperature, shading, soiling and operating conditions affect actual production.

What warranties should a solar quotation include?

Look for separate information covering panels, inverter, batteries where applicable, installation workmanship and structural components where relevant.

Should grid-connection costs be included in the quotation?

The proposal should clearly state which application, interconnection, metering or regulatory services and fees are included and which remain the customer's responsibility.

How can I compare two solar quotations?

Compare system capacity, exact equipment, quantities, protections, structure, installation scope, warranties, expected generation, payment terms and exclusions rather than comparing price alone.