15 Questions to Ask Before Signing a Solar Contract in India

A rooftop solar quotation can look attractive while leaving important details—equipment models, approvals, warranties, payment milestones or performance assumptions—unclear.

Check equipment, pricing, warranties, approvals and service terms before signing your rooftop solar contract.

Before paying an advance or signing an agreement, ask the installer these questions and get the answers in writing. This is especially important for residential grid-connected systems, where DISCOM procedures and government-scheme requirements may affect the project.

1. What Exactly Is Included in the Quoted Price?

Ask for an itemised scope, not just a single “₹/kW” figure. It should state whether the price includes modules, inverter, mounting structure, AC/DC cabling, protection devices, earthing, monitoring, labour, transport, taxes, application work, metering support and any required civil or waterproofing work.

Also ask what is excluded. A low quotation can become expensive if essential items appear later as extras.

2. Which Exact Solar Modules Will Be Installed?

Ask for the manufacturer, model number, wattage per module, quantity, technology and applicable warranties—not only the brand name.

If the project falls under a government-supported scheme or another category with equipment-eligibility rules, ask the vendor to confirm the current ALMM, domestic-content or other applicable requirements in writing. MNRE updates its Approved List of Models and Manufacturers, so eligibility should be checked against current rules.

3. Which Inverter Model Will I Receive?

The contract should identify the inverter make, model and rated capacity. Ask whether it is grid-tied, hybrid or designed for battery backup.

A normal grid-connected inverter generally does not keep your home powered during a grid outage. If backup matters, the design must specifically include the required backup architecture and safe grid isolation.

4. How Was the Recommended System Size Calculated?

Ask why the installer recommends 3 kW, 5 kW or another size. The answer should consider electricity consumption, sanctioned load, roof area, shading, orientation and local interconnection rules.

Remember: kW measures power capacity, while kWh measures energy generated or consumed over time.

5. What Generation Can I Reasonably Expect?

Request an annual generation estimate and its assumptions. Ask what irradiation data, shading, temperature, inverter, cable and other system losses were considered.

Treat “guaranteed savings” cautiously unless the guarantee, exclusions and remedy are written clearly. Actual output depends on location, roof orientation, shading, weather, soiling, equipment quality and system losses.

6. Who Handles DISCOM Approvals and Metering?

The agreement should assign responsibility for applications, technical feasibility, documentation, inspection, metering, commissioning and portal updates.

Net metering, net billing and gross metering rules can vary by state, DISCOM, consumer category and system size. Do not assume one process applies everywhere. Official net-metering agreements themselves operate with reference to applicable state regulations and DISCOM procedures.

7. If I Am Claiming a Subsidy, What Must the Vendor Do?

Ask whether the installer is eligible under the applicable scheme and whether the proposed equipment meets current requirements.

For PM Surya Ghar-related installations, official guidance routes eligible residential consumers through the National Portal and applicable registered-vendor process. MNRE guidance also advises consumers to incorporate applicable technical standards and specifications into the vendor agreement.

Do not rely only on a salesperson’s statement that subsidy is “guaranteed”.

8. What If Approval or Subsidy Is Delayed or Rejected?

Ask what happens if the proposed capacity is not approved, redesign is required, subsidy is delayed, or the application is rejected.

The contract should explain refund conditions, payment obligations and which risks are controlled by the vendor versus the DISCOM or government agency.

9. What Are the Payment Milestones?

Avoid vague terms such as “80% advance, balance on completion” unless completion is defined.

A clearer contract links payments to milestones such as material delivery, installation, testing, commissioning and handover. It should also state the total price, taxes, refund conditions and consequences of delay.

10. What Warranties Apply—and Who Will Honour Them?

Ask separately about:

·        module product warranty;

·        module performance warranty;

·        inverter warranty;

·        other component warranties;

·        installation or workmanship warranty; and

·        service support.

A manufacturer warranty is not the same as an installer workmanship warranty. Ask who handles claims, whether labour or transport is chargeable, and what happens if the installer stops operating.

11. What Safety Measures Are Included?

Electrical and rooftop work should be carried out by qualified professionals. Ask the vendor to document earthing, overcurrent protection, surge protection, isolation, cable routing and other protections required for your installation.

The Central Electricity Authority maintains regulations relating to electrical safety and supply, including the 2023 regulations and a 2026 amendment. The contractor should follow the requirements applicable to your installation and utility connection.

Do not open electrical enclosures or alter rooftop DC wiring unless you are appropriately qualified.

12. How Will the Mounting Structure Affect My Roof?

Ask how the structure will be fixed, what material and corrosion protection are used, and how waterproofing will be protected.

For tiled, metal-sheet or fragile roofs, the fixing method matters. The contract should state who is responsible for roof damage or water ingress caused by installation work.

13. What Documents and Monitoring Access Will I Receive?

Confirm whether monitoring is included and whether the account remains accessible to you.

At handover, ask for equipment serial numbers, datasheets, warranty documents, invoice, approval records, commissioning documents, monitoring credentials and shutdown instructions.

14. What After-Sales Service Is Included?

Ask about service-response commitments, preventive maintenance, fault support and chargeable visits.

Clarify whether cleaning is included, whether monitoring is actively reviewed and how inverter or communication failures will be handled.

15. What Happens If the Project Is Delayed or Equipment Changes?

The contract should include a realistic schedule and a process for approving changes.

If the installer proposes a different module, inverter or major component, require your written approval for an equivalent or better specification. Also define cancellation, termination, delay and dispute-resolution terms.

A Simple Rule Before You Sign

"If a promise matters to your decision, put it in the contract."

A good solar agreement clearly identifies the equipment, scope, price, responsibilities, timeline, approvals, warranties and remedies. Compare quotations on the same technical scope so you are comparing like with like.

Before final payment, verify that the installed equipment matches the contract and that commissioning, documentation and monitoring access are complete.

Conclusion

A rooftop solar system may operate for many years, while the sales discussion may last only a few hours. Spending extra time on the contract can prevent misunderstandings about equipment, approvals, subsidy, generation expectations and after-sales support.

Use these questions as a pre-signing checklist. For unusually large, financed or legally complex projects, consider an independent solar professional or legal adviser.

If you are planning rooftop solar, continue learning about system sizing, net metering, inverter selection and solar warranties before choosing an installer.