The One Signal That Works: Installation Year Plus Inverter Type
Standard string inverters from SolarEdge, Fronius, and SMA typically carry only a 10 to 12-year warranty. That means a system installed roughly between 2013 and 2016 is now sitting inside, or approaching the far edge of, that exposure window as of 2026. Installation year alone is not enough, though, because it does not distinguish a genuine repowering candidate from a system that was never exposed to this gap in the first place.
Why Enphase Systems Don’t Fit This Profile
Enphase is the one inverter technology on the market that ships a standard 25-year warranty out of the box, matching the panel warranty directly rather than lapsing a decade or more early. A 2013-to-2016-vintage system running Enphase microinverters is not a repowering candidate on warranty-gap grounds, even though its installation year matches the window above. Installation year is the first filter, inverter brand and type is the second, and a candidate genuinely needs both before this specific pitch applies.
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Book a Solar CallA Second, Overlapping Signal: Is the Original Installer Still in Business
A separate, overlapping signal worth checking is whether the homeowner’s original installer is still operating at all. Titan Solar Power, SunPower, Sunnova, PosiGen, and Freedom Forever have all filed for bankruptcy or ceased major operations between 2024 and 2026, part of a wider wave of more than 100 US solar company bankruptcies and closures since 2023, and a homeowner whose system traces back to one of those companies is simultaneously a solar-orphan candidate and, if the installation year and inverter type also line up, a repowering candidate. The two signals reinforce each other rather than competing: a system that is both old enough to be near end-of-warranty and installed by a company that no longer exists is a stronger candidate than one that only meets one condition.
What This Methodology Doesn’t Give You
This is a targeting methodology, not a population count. It tells a sales team which specific, checkable facts, installation year, inverter brand, and original installer status, identify a genuine candidate. It does not attempt to estimate how many US solar systems currently fall into that window nationally, since that is a separate statistical question requiring its own dataset rather than an extension of the mechanical facts above. Treat any specific national count offered elsewhere with the same scrutiny this guide applies to a single homeowner’s system.
| Signal | What Qualifies | What Doesn’t |
|---|---|---|
| Installation year | Roughly 2013 to 2016, inside or approaching the 10 to 12-year string-inverter warranty window as of 2026 | Systems installed after roughly 2016 are typically still inside warranty |
| Inverter type | String inverter from SolarEdge, Fronius, SMA, or similar | Enphase microinverters carry a 25-year warranty and do not fit this profile |
| Original installer status | Installer among the bankruptcy-wave names (Titan, SunPower, Sunnova, PosiGen, Freedom Forever) or otherwise out of business | An installer still in business and reachable for service |
The strongest candidates meet more than one signal at once.
What this means for you
- Standard string inverters (SolarEdge, Fronius, SMA) typically carry only a 10 to 12-year warranty, meaning a system installed roughly 2013 to 2016 is now inside or approaching that exposure window.
- Enphase microinverters ship a 25-year warranty matching the panel warranty, so an Enphase system in the same installation-year window is not a warranty-gap candidate.
- A homeowner whose original installer, among them Titan Solar Power, SunPower, Sunnova, PosiGen, or Freedom Forever, has since gone bankrupt is a second, overlapping signal worth checking alongside installation year.
- Installation year and inverter type identify individual candidates. They do not estimate how many systems nationally fall into this window, a separate question this guide does not attempt to answer.
Sources
The external data in this guide draws on the sources below. Figures described in the text as estimates or industry triangulations are directional and are not attributed to a single dataset.
- GreenLancer, solar inverter warranty guide
- Solarinsure, complete list of solar bankruptcies and closures
- pv-magazine-usa, Freedom Forever files Chapter 11 bankruptcy
- EnergySage, SunPower is bankrupt, what now