Three warranties, three different layers of protection.

1. Panel performance warranty — 25 years

A Tier-1 monocrystalline solar panel from Q Cells, REC, SunPower, LG, or Panasonic comes with a 25-year power-output warranty: the manufacturer guarantees the panel will produce at least 85–92% of its rated wattage at year 25.

Translation: a 400 W panel covered at 92% will produce at least 368 W at year 25. In real world Long Island sunlight, panels typically over-perform their warranty curves — most installs see 90%+ retention at year 25 in practice.

On top of the performance warranty, Tier-1 brands also include a 12–25 year product warranty against defects (delamination, hotspots, junction-box failure). Budget brands often skip the product warranty.

2. Inverter warranty — 12 years (extendable)

Inverters work harder than panels — they handle every kWh the system produces, day in and day out. Standard warranties: Enphase microinverters ship with a 25-year warranty, SolarEdge and other string inverters with 12 years (extendable to 20–25 for an added fee).

The most likely failure mode in any solar system over 15 years is an inverter — Long Island humidity + summer heat stresses electronics. The warranty includes a free replacement unit; the labor to swap it is normally out of pocket, so it is worth checking what a prospective installer charges for that before you sign.

3. Workmanship warranty — 10 years

The workmanship warranty covers the installer's labor: roof penetrations + flashing, panel mounting, electrical conduit, conduit-to-junction-box terminations, monitoring setup. Standard across the Long Island residential solar industry is 10 years.

The most common workmanship claim is a roof leak. Properly flashed and sealed solar mounts almost never leak — but if one does, the workmanship warranty covers full repair, including any drywall or insulation damage caused by the leak.

What happens if your installer goes out of business?

Solar installers go under more than you'd think — especially residential-only shops that ride the federal tax credit cycle. When that happens:

- Panel and inverter warranties are unaffected. The manufacturer honors them directly — Q Cells, Enphase, Tesla, SolarEdge, etc. all have direct warranty claim paths. You file with the manufacturer; they ship a replacement.

- Workmanship warranty lapses. If your installer is gone, the workmanship warranty has no one to honor it. This is the real risk of going with a shop that may not be around in 10 years.

- Practical consequence. A homeowner with an orphaned system can still claim equipment from the manufacturer, but has to find a contractor willing to do the labor. That is worth pricing into the decision when you compare quotes today.

Before you sign

Warranty terms belong in the contract, not in a brochure — panel product and power-output terms, inverter term and whether it is extendable, battery term if one is included, the workmanship period and exactly what it covers, and who holds the monitoring subscription. Ask for the warranty letter before you sign; if an installer cannot produce one, walk away.