Solar Contract Checklist: 15 Things to Verify Before You Sign

Print this page or open it alongside your solar contract. Go through each item one by one. If anything is missing from the contract, ask the installer to provide it in writing before you sign. Do not rely on verbal promises — solar contracts are long-term obligations, and the written terms are what matter in the end.

Verify the exact make, model, and quantity of each major component: solar panels (manufacturer, model, wattage), inverter(s) (manufacturer, model type — string vs. microinverter vs. optimizers), racking/mounting system, and battery (if included). The contract should list all of these individually, not as a single line item. Cross-check against the proposal. Confirm the total system size in kW DC and expected annual kWh production.

Premium panel manufacturers (SunPower/Maxeon, REC, Qcells, Silfab, LONGi, JinkoSolar) typically offer 25–30 year product warranties and 25–30 year linear power output warranties. The warranty should guarantee at least 80–85% of rated output at year 25. Some budget panels offer shorter warranties or non-linear degradation guarantees. If the contract says 'standard manufacturer warranty' without specifying the duration and terms, ask for the full warranty document.

Inverters typically have shorter warranties than panels. Microinverters (Enphase, Hoymiles): 25 years. String inverters (SolarEdge, SMA): 10–12 years standard, extendable to 20–25 years for an additional cost. Power optimizers (SolarEdge): 25 years. Confirm the inverter warranty period in the contract. If it is shorter than the panel warranty, confirm the cost of a replacement when the inverter fails. Inverter failure before year 15 is common and can cost $1,500–$3,000 to replace.

This covers labor for repairs caused by faulty installation. SEIA recommends a minimum 10-year workmanship warranty. Some installers offer 25 years. If the contract only offers 1–2 years, that is a red flag. Roof penetration leaks are one of the most common post-installation issues — the warranty should specify coverage for leak repairs related to the solar installation.

Lease and PPA contracts often include a production guarantee: the provider guarantees the system will generate a minimum number of kWh per year. If production falls short, the provider compensates you, typically as a credit. Verify: the guaranteed kWh per year, the compensation rate for shortfalls (full payment credit or only partial), and what is excluded from the guarantee (shading from new construction, utility curtailment, grid outages). Independent testing labs like UL or CSA should certify that the system meets safety standards.

Solar installation requires drilling into your roof for mounting. The contract should specify: who is responsible for roof repairs if the installation causes a leak, the warranty period for roof penetrations (10+ years is standard from reputable installers), and what happens if a roof replacement is needed during the solar system's lifetime. Some contractors offer a bonded roof penetration warranty separate from the general workmanship warranty.

Verify that the system includes monitoring (online portal or app) and confirm it is included in the price, not an optional upgrade. For leases and PPAs: confirm you have read access to monitoring data. For purchased systems: confirm you have full control. Check whether the monitoring platform charges an ongoing subscription fee after the first year.

If financing, check: APR and whether it is fixed or variable, dealer fees (often 15–30% for zero-down loans — these are added to the principal, not disclosed as a percentage), prepayment penalties (some solar loans charge a penalty for early payoff), and whether the loan is secured (UCC lien filed against your home, which can affect credit and home equity). Confirm the total financed amount, not just the monthly payment.

For leases and PPAs: contract length (typically 20–25 years), monthly payment or per-kWh rate, annual escalator clause (1–3% yearly increase is common — ask what the payment will be in year 10 and year 20), buyout option (can you buy the system early and at what price?), renewal options (what happens at the end of the contract term), and removal cost (who pays if the system needs to be removed for roof repair). The contract should state the full payment schedule or rate schedule, not just the first year.

The contract should state: who handles the interconnection application with the utility (most installers handle this, but confirm), the expected timeline for interconnection approval, and which net metering or net billing tariff applies. In California (NEM 3.0), Massachusetts, New York, and other states, the specific tariff determines export credit rates. If the contract assumes a net metering tariff that no longer exists in your area, that is a problem. Ask the installer to state the current applicable tariff by name.

Confirm the installer handles all required permits (building, electrical, and HOA if applicable). The contract should specify: who applies for permits, who covers permit fees, who schedules inspections, and who covers re-inspection fees if the initial inspection fails. Failure to obtain proper permits can create issues when selling the home or filing insurance claims.

The contract should include: estimated installation start date, estimated completion date, and what happens if the installer misses these dates (is there a penalty or right to cancel?). For lease/PPA: what is the timeline from signing to interconnection and when do payments start? Payments should start only after the system is operational and interconnected, not at contract signing.

For purchased systems: confirm the warranty transfers to a new homeowner if you sell. For leased/PPA systems: confirm the new buyer can assume the contract subject to credit approval. Check: are there transfer fees? (Some contracts charge $250–$500). What is the credit qualification requirement for the buyer? Is there a buyout option if the buyer does not qualify? (If the buyer cannot assume the lease, you may need to buy out the contract — often at a depreciated value).

Federal law gives you a 3-business-day right to cancel (rescind) for contracts signed away from the seller's regular place of business. Some states offer longer cancellation periods. Check: does the contract state your cancellation rights? Are there penalties for cancellation after the rescission period? Can you cancel if the utility denies interconnection? (Some contracts try to hold you responsible for the full system cost even if the utility will not approve the interconnection.)

Check: does the contract require binding arbitration? (If yes, you waive your right to sue in court. Some contracts include a class action waiver.) Which state's law governs the contract? Who pays legal fees if there is a dispute? (If the contract says 'prevailing party pays legal fees,' that cuts both ways — it discourages nuisance claims but can also make you liable for the installer's legal costs if you lose.)