A low solar quote can conceal missing protection equipment, an unsuitable roof design, weak warranty support, or an approval problem that delays operation. By checking the company, site survey, system design, contract, and after-sales obligations in a fixed order, you can compare proposals on evidence rather than package size or sales promises.
Key takeaways
- Match the quotation, contract, invoice, permits, and warranties to one legal entity.
- Ask for the site survey, roof-load findings, shading measurements, and proposed electrical layout.
- Confirm panel, inverter, protection-device identities, ratings, warranties, and code compliance.
- Define monitoring, maintenance, workmanship warranties, and subcontractor responsibility before signing.
Verify the company’s legal status, role, and local authority
Establish accountability by matching the legal entity on the quotation, contract, invoice, permits, and warranties. Check its company registration, tax identification, business address, electrical licence, liability insurance, workers’ compensation cover, and evidence of completed rooftop projects. Ask who employs the installation crew and who remains responsible if a subcontractor causes damage.
Confirm which role you are hiring:
- A manufacturer makes equipment but may not install or obtain approvals.
- A distributor supplies equipment and may refer installation to another party.
- An EPC contractor designs, procures, installs, commissions, and coordinates approvals.
- An electrical contractor handles defined electrical work, not necessarily the complete project.
- A lead-generation reseller may only pass your details to an unnamed installer.
Name the responsible EPC contractor in the contract, even when a manufacturer or distributor sells the system. Require an itemised quotation, system design, single-line diagram, structural assessment, installation scope, warranty terms, payment schedule, and named project manager.
Ask the company to state the code edition, local authority having jurisdiction, permit requirements, inspection steps, and utility interconnection rules. Obtain written utility approval identifying export limits, fees, studies, protection equipment, and permission-to-operate conditions; mechanical completion does not authorise grid export.
Before signing, have a qualified party verify roof remaining life, attachment locations, structural capacity, waterproofing, and local wind, snow, and seismic loads.
Test the site survey before approving the design
Approve a design only after the installer has inspected the roof, electrical connection, and surrounding property in person. A phone estimate can miss a short roof life, unsafe access, a service-panel limit, or a tree that shades the array after 2 p.m.
1. Demand roof measurements showing usable length, width, obstructions, setbacks, access paths, and attachment locations. The drawing should also record orientation and tilt, roof age, covering type, drainage paths, skylights, vents, parapets, and areas that cannot be penetrated.
2. Ask for a shade analysis covering nearby trees, buildings, tanks, poles, and future obstructions. Require the survey to show shade by time of day and season; a roof that looks clear at noon can lose production during morning and winter hours.
3. Require a structural assessment by a qualified professional. It must address roof remaining life, racking and attachment loads, waterproofing details, and local wind, snow, seismic, and rooftop conditions—not panel weight alone. Installing on a roof due for replacement can force module removal and a second mobilisation.
4. Have the installer inspect the meter, main switchboard, earthing, cable routes, service capacity, fire access, equipment location, and construction access. Request the proposed code edition, permitting authority, utility interconnection rules, export limit, and inspection requirements in writing; a design accepted elsewhere can fail your local authority having jurisdiction.
Insist on signed survey drawings and photographs before approving the layout.
Check system sizing, equipment identity, and code compliance
Size the array from 12 months of electricity bills, not from roof area alone. Compare the proposed annual generation with your consumption, check the sanctioned load against the proposed inverter capacity, and ask the designer to show assumptions for shading, orientation, seasonal output, and future load growth.
Demand exact equipment identities. The quotation must state each panel model number, wattage, quantity, inverter model and inverter capacity, mounting system, protection devices, cable sizes, and monitoring equipment.
“Tier 1” is a marketing label, not a safety certification; check module and inverter certificates accepted in your jurisdiction, such as UL 61730 in the United States or IEC 61215 and IEC 61730 internationally.
Use this checklist before approving the design:
- Confirm the roof has adequate remaining life, attachment points, waterproofing, and structural capacity for local wind, snow, seismic, and rooftop loads—not panel weight alone.
- Request the adopted electrical, structural, and fire code editions, the permitting authority, inspection stages, and utility interconnection rules in writing.
- Obtain the utility’s written approval, including export limits, fees, study requirements, protection equipment, and permission-to-operate conditions. Mechanical completion does not permit grid export.
- For batteries, require a one-line diagram showing service equipment, transfer equipment, critical-load panel, battery limits, rapid shutdown, and anti-islanding functions. “Backup” may cover only selected circuits.
- Check that the design fits the utility’s sanctioned load and local safety rules; a system approved elsewhere can fail your authority having jurisdiction.
Compare the quotation and contract line by line
Do not sign until the itemised quotation, contract scope, and drawings describe the same system. Have a qualified party verify roof remaining life, attachment locations, structural capacity, waterproofing, wind, snow, seismic, and rooftop loads. A roof replacement after installation can force module removal and a second mobilisation.
| Quotation line | Require in writing | Risk if missing |
|---|---|---|
| System design | Panel wattage and model, inverter capacity and model, annual energy, assumptions, P50/P90 figures, single-line diagram, mounting structure material, cable sizes, earthing, monitoring, and protection devices | You cannot compare output, equipment, or safety scope |
| Commercial scope | Labour, transport, taxes, permits, utility fees, maintenance, payment stages, completion date, exclusions, and responsibility for damage | The lowest price can conceal major extras |
| Approvals | Code edition, permitting authority, AHJ inspections, utility interconnection rules, export limit, study requirements, application fees, and permission-to-operate conditions | A finished system may remain unable to export power |
| Warranty | Separate module product and performance warranties; inverter term and replacement process; covered labour, travel, shipping, removal, exclusions, degradation formula, claims, monitoring, and firmware support | A long warranty may still leave you paying for repair |
Ask who pays if the utility rejects the design or the AHJ requires changes. Compare every line against competing offers, and reject allowances such as “standard protection” unless the devices and ratings are named.
Assess service, monitoring, and responsibility after commissioning
Make the post-installation contract assign every failure to a named party, a response time, and a remedy. Without that detail, the installer can blame the equipment maker, roofer, or utility while your system remains idle.
Put these obligations in writing:
- Roof leaks: state the workmanship warranty term, inspection and response deadline, repair method, and whether membrane restoration, interior damage, labour, and consequential damage are covered. Exclude only identified pre-existing defects, storm damage, or later-roofer damage.
- Inverter warranty logistics: specify who submits the claim, pays shipping, labour, travel, and removal, and whether a replacement can be a different model. Confirm that monitoring and firmware support continue if the installer closes.
- O&M service levels: define alarm acknowledgement, site response, corrective-action deadline, preventive inspections, vegetation and soiling duties, spare-parts policy, reporting, and exclusions. Treat preventive maintenance, corrective maintenance, monitoring, and reporting as separate services.
- Monitoring-data ownership: require your own portal credentials or an exportable data feed covering interval production, inverter alarms, and revenue-grade meter data. A contractor-controlled login can disappear with the contractor.
- Approval responsibility: identify who obtains the utility’s written permission to operate, pays application or study fees, installs required protection, and resolves export limits or AHJ comments.
Check module product and performance warranties separately; neither automatically includes shipping, removal, labour, or lost generation. Ask Madhuri Solar to show these assignments in its service schedule, not merely promise support in conversation.
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Frequently asked questions
Which legal documents should you check before hiring a solar company?
Match the company name across the quotation, contract, invoice, permits, and warranties. Check company registration, tax identification, business address, electrical licence, liability insurance, workers’ compensation cover, and completed-project evidence.
What should a rooftop solar site survey include?
Review roof condition and load capacity, shading measurements, roof dimensions, electrical-panel location, cable routes, access requirements, and the proposed equipment layout before approving the design.
How can you check whether a solar system is correctly sized?
Compare the proposed system size with your electricity-use records, roof area, shading results, inverter capacity, panel ratings, expected energy yield, and the site’s electrical connection limits.
What should you compare in solar quotations and contracts?
Compare equipment models, quantities, mounting structure, protection devices, permits, taxes, civil and electrical work, payment stages, exclusions, completion criteria, warranties, and delay or cancellation terms.
Who is responsible after a rooftop solar system is commissioned?
The contract should name the party responsible for monitoring, maintenance, fault response, warranty claims, documentation, and damage caused by employees or subcontractors.
