OwlYour solar system is producing less than your contract's guarantee promised, you've documented the shortfall, and your installer is slow to respond. A written demand letter is the first formal step. This page gives you a free, copy-friendly template you can adapt, plus guidance on when to send it and what to attach.
A note on what this page is. This is a free, public template — not legal advice. OwlWatt is not a law firm. The template states facts and requests a remedy; it does not opine on your legal rights. Whether to send it, what to include, and what comes next are questions for a licensed attorney in your state. A licensed attorney can also use your documentation as evidence.
When and Why to Send a Written Demand
A phone call leaves no record. A written demand does. It puts your claim in front of the installer in specific, dated, documented terms — and it gives them a clear chance to resolve the matter before you escalate to a state Attorney General complaint or an attorney.
Send a written demand once you have a documented shortfall in hand and an informal request hasn't worked. Email creates a record; a mailed letter (certified, return receipt requested) creates a stronger one. Many homeowners get a response at this step simply because a specific, sourced demand is harder to brush off than a phone call.
In some states a written demand is more than good practice — it's a legal prerequisite. Massachusetts, for example, requires a written demand at least 30 days before filing certain consumer-protection claims (see Massachusetts Chapter 93A and solar installers); California's CLRA and the Texas DTPA have their own pre-suit notice rules too. For how the major states' consumer-protection statutes apply to a solar installer, see California, Texas, Florida, New Jersey, and New York. Whether any applies to you is a question for a licensed attorney in your state.
A strong demand letter does five things:
- Identifies you and your system — your name, address, and the system's size and install date.
- Quotes the production-guarantee clause from your contract by section number, including the kWh commitment, the measurement period, and the remedy it names.
- States the documented shortfall — guaranteed production minus actual production, weather-adjusted so it isn't dismissed as "just a cloudy year."
- States the dollar amount you're claiming, and shows the calculation.
- Requests a specific remedy and sets a deadline — the remedy the contract names, with a reasonable response window.
If your contract's remedy clause is vague or missing entirely, quoting it precisely gets harder — that gap is exactly what our guide to solar production guarantee contract red flags covers, for readers who haven't signed yet and want to catch it before it becomes a demand-letter problem.
The Template
Fill in every [bracketed] field. Keep it brief and factual. Select the text below to copy it.
[Your Name]
[Your Street Address]
[City, State, ZIP]
[Email] · [Phone]
[Date]
[Installer / Company Name]
[Attn: Warranty or Contract Contact, if named in your agreement]
[Company Street Address]
[City, State, ZIP]
Re: Demand for relief — production-guarantee shortfall, contract no. [contract number]
Dear [Installer / Company Name],
I am the owner of a [size] kW (DC) rooftop solar system that [Installer / Company Name] sold and installed at [system address]. The system was installed in [install month/year] under contract no. [contract number], dated [contract date].
Our contract includes a production guarantee at [section/clause number], under which you guaranteed the system would produce at least [guaranteed kWh] kWh over [measurement period] and agreed to [the remedy the contract names — e.g., compensate me at $[rate] per kWh of shortfall].
The system has not met that guarantee. Over [measurement period], the system produced [actual kWh] kWh against a guaranteed [guaranteed kWh] kWh — a shortfall of [shortfall kWh] kWh. This figure is weather-adjusted: the expected output was modeled against actual local weather for the period using NREL's PVWatts model, so the shortfall is not explained by an unusually cloudy or snowy year. Applying the contract's compensation rate of [$ rate per kWh], the amount owed under the guarantee is approximately [$ amount owed]. I have the underlying production report and data and can provide them on request.
I am requesting that you [the specific remedy — e.g., pay the $[amount] shortfall compensation the contract provides for] within [number, e.g., 30] days of the date of this letter. Please respond in writing to the contact information above.
I would prefer to resolve this directly and promptly. If I do not receive a response by [deadline date], I will consider further steps available to me, which may include a complaint to my state's consumer-protection authority and consultation with an attorney.
Sincerely,
[Your Name]
Enclosures: copy of contract; production report and data; prior correspondence.
These figures are the heart of the letter. OwlWatt documents your exact production shortfall against your contract's guarantee using NREL's PVWatts model — the weather-adjusted kWh gap and the dollar amount owed, in a report you can attach. Start free → and pull the numbers this letter asks for. OwlWatt is not a law firm and does not provide legal advice; a licensed attorney in your state can use this documentation as evidence.
What to Attach
A demand letter is far stronger with the supporting documents attached. Include three things:
- The signed contract — at minimum the page(s) containing the production-guarantee clause, the kWh commitment, the measurement period, and the remedy. The whole contract is better if you have it.
- Your production report — the documented shortfall: guaranteed kWh, actual kWh, the weather-adjusted expected baseline, and the dollar calculation. OwlWatt produces this automatically for Enphase systems. The weather-adjusted baseline is the piece that defeats the "it was just bad weather" response.
- The email thread — any prior correspondence showing you raised the issue and what response (if any) you got. Read receipts, if you have them, help establish the timeline.
Keep a copy of everything you send, and note the date you sent it and how. If you mail it, send it certified with return receipt requested and keep the receipt.
What Comes After the Letter
If the demand resolves the matter, you're done. If it doesn't, the letter becomes the first dated step in a documented escalation. Our guide to escalating a solar production claim walks through the full ladder — written demand, state Attorney General complaint, and consulting an attorney — and includes a 15-state Attorney General consumer-protection directory.
If your installer has gone out of business, the path is different; see when your solar installer goes bankrupt.
Further Reading
- Solar Production Guarantee Contract Red Flags — the clauses to check before you sign, so a vague remedy never becomes a demand-letter problem.
- Escalating a Solar Production Claim — the full escalation ladder after the demand letter, plus a state Attorney General directory.
- Massachusetts Chapter 93A and Solar Installers — when a demand letter is a legal prerequisite, and what double/treble damages and attorney's fees can mean.
- How to File a Production Shortfall Claim — assembling the documentation package the letter relies on.
- Solar Production Guarantees, Explained — what the guarantee clause actually obligates the installer to do.
- Weather-Adjusted Solar Production — why the weather-normalized baseline is the figure that holds up under pushback.
The Numbers Make the Letter.
A demand letter is only as strong as the shortfall it documents. OwlWatt tracks your production against your contract's guarantee and produces the weather-adjusted, dollar-denominated report you attach to the letter. OwlWatt is not a law firm and does not provide legal advice.
Start free and document the shortfall behind your demand.