Your solar company changed hands or went bankrupt. The guarantee may not have.
We check your system's real output against your lease's production guarantee, and draft the claim letter if a shortfall is found.
No account required. Works for any company: you enter your own lease numbers. Sunrun customer? See the Sunrun performance guarantee page. New here? Read the Terms of Service first.
| True-up period | Guaranteed | Actual | Variance, before any carryover |
|---|---|---|---|
| Period one | 18,400 | 15,760 | -2,640 |
| Period two | 18,400 | 18,610 | +210 |
| Period three | 17,900 | 14,980 | -2,920 |
| Periods with a shortfall | 2 of 3 |
Who services your lease now?
For a SunPower or Sunnova system, SunStrong Management's own pages point to itself. For a PosiGen lease, Omnidian's PosiGen customer support site points to Renewbrook. Your latest bill is the final word.
| Original company | Company to ask | What its own site says |
|---|---|---|
| SunPower | SunStrong Management | SunStrong describes its app as "formerly mySunPower", for former SunPower customers. |
| Sunnova | SunStrong Management | SunStrong's customer service form lists Sunnova as an original provider. |
| PosiGen | Renewbrook | Omnidian's PosiGen customer support site says Renewbrook has taken over PosiGen customers' assets. |
A shortfall, filled in by the kilowatt-hour.
Each filled bubble is 1,000 kWh your system actually produced. An outlined bubble is production the guarantee promised and the roof did not deliver.
- True-up period oneGuaranteed 18,400, actual 15,7602,640 kWh short
- True-up period twoGuaranteed 18,400, actual 18,610target met
- True-up period threeGuaranteed 17,900, actual 14,9802,920 kWh short
1,000 kWh your system producedpromised by the guarantee, not producedEach bubble is filled to scale. Example numbers only.
Four lines. You only see the last one if a shortfall is found.
- EnterYour servicer, and the guarantee numbers from your lease.$0
- CompareYour output against your guarantee. Enphase, SolarEdge, or an upload.$0
- ReadA shortfall, or no shortfall. Honest either way.$0
- ClaimClaim letter and evidence packet. Only when a shortfall is found.$99
Free to check. $99 only if a shortfall is found. See the full steps.
Optional: GuaranteeCheck Plus is $3.99 per month or $29.99 per year. It lowers the claim letter and evidence packet to $49 instead of $99 while active, records your checks (a record only: nothing re-runs automatically) and emails you before the true-up date of each system you track. Letters are not included. Plus renews automatically; cancel any time. See Plus pricing.
Someone who is not the company that set the number.
GuaranteeCheck is not owned by, paid by, or partnered with any solar servicer. It compares numbers and drafts a letter. It does not contact your servicer or file anything, and you decide whether to send the letter. It is not legal advice. Read the methodology.
Filled box: the party with a financial stake in the number.
- Step 1The servicer sets the numberWrote the guarantee into your contract, and pays any credit.Has a stake
- Step 2Your system measures itOutput comes from your Enphase or SolarEdge account, or your own upload.No stake
- Step 3GuaranteeCheck comparesChecks the two numbers and drafts a letter. Owned by no servicer.No stake
- Step 4You decideYou read the letter and send it, or not. We never contact your servicer.Your call
Read the research before you write.
- Read
Did my Sunnova production guarantee survive the bankruptcy?
What a Chapter 11 filing does and does not tell you, and how to check your own contract.
- Read
How to check whether your production guarantee was met
The numbers to gather and the arithmetic, step by step.
- Read
What is a production guarantee true-up?
Definition, the cycle, surplus carryover and a worked example.
- Read
Claim checklist for SunPower, Sunnova and PosiGen homeowners
What to gather, what to send and where, with the source of each date shown.
All guides · All servicers · Shortfall estimator
Checking your utility's net-metering true-up bill, not a lease guarantee? Use the free true-up bill check.
Before you ask.
Is this actually free?
The check is free. You only pay $99 if a shortfall is found and you want the claim letter.
Are you affiliated with my servicer?
No. We are not owned by, paid by, or partnered with any solar servicer.
What if there is no shortfall?
Then we tell you that, for free, and you are done.
Did my guarantee survive the bankruptcy?
That depends on your own contract and any notices you received, so we cannot decide it for you. Our guide shows what to check. Read the guide, or see the Sunnova production guarantee page.
What do I need to start?
Your servicer name and the production guarantee numbers from your lease. The check then compares your actual output, from Enphase, SolarEdge or an uploaded export, to what your contract promised.
Checking costs you nothing. Find out if a credit is due.
Hero photo: Michael Pointner on Unsplash.