Solar 101
How long do solar panels last?
5 min read
Tier-1 monocrystalline solar panels are designed to produce usable electricity for 25-30 years. Manufacturer warranties cover the full 25 years on parts and on guaranteed minimum output. The actual production curve is gradual: panels lose roughly 0.4-0.5% of their rated wattage per year — by year 25, a panel still produces about 90% of its day-one output.
Inverters and batteries have shorter lives. Here's the honest breakdown of every component you'll be living with on your roof.
Component lifespan at a glance
| Component | Manufacturer warranty | Typical real-world life |
|---|---|---|
| Solar panels (tier-1 mono) | 25 years | 30+ years |
| Microinverters (Enphase) | 25 years | 25+ years |
| String inverter | 10–12 years | 12–15 years |
| Tesla Powerwall 3 | 10 years | 12–15 years |
| Enphase IQ Battery 5P | 15 years | 15+ years |
| Mounting hardware | 25 years (workmanship) | 30+ years |
What 'panel degradation' actually looks like
A panel rated 400W on day one will produce roughly:
- Year 1: 99-100% (~398-400W)
- Year 5: 98% (~392W)
- Year 10: 96% (~384W)
- Year 15: 94% (~376W)
- Year 20: 92% (~368W)
- Year 25: 90% (~360W)
What kills panels (and how to avoid it)
- Hail strikes above 1" diameter at high velocity — rare in Texas; covered by homeowner's insurance + manufacturer warranty.
- Micro-cracks from foot traffic — prevent by leaving the roof to install / service crews only.
- Hot spots from shading — modern panels with bypass diodes handle partial shade; severe shade still degrades affected cells faster.
- PID (potential-induced degradation) — a manufacturing-era issue mostly solved in tier-1 panels post-2018.
- Connector corrosion at panel edges — prevented by tier-1 weatherproofing and 25-year manufacturer warranty.
When to replace components
- String inverter — usually around year 12-15. Most homeowners with string inverters plan one inverter swap during the panel's life.
- Battery — when capacity drops below ~70% of rated, typically year 12-15 for Powerwall, year 15+ for Enphase IQ.
- Panels — typically not replaced; system runs at 90% output indefinitely after the warranty period.
- Microinverters — same 25-year life as the panels they sit under, so usually no swap needed.
Common questions
Frequently asked
- How long do solar panels really last?
- 25-30 years of usable production. Manufacturer warranties guarantee 25 years; the panels keep producing electricity well beyond that, just at gradually reduced output (down to ~90% of day one by year 25).
- Do solar panels stop working after 25 years?
- No. They keep producing — just at slightly lower output each year (about 0.4-0.5% degradation per year). Many systems are still running at 30+ years with 85% output.
- Will I have to replace anything during the panel's life?
- If you have a string inverter, expect one inverter swap around year 12-15 ($1,500-$3,000). If you have microinverters or battery storage, those have their own warranties (15-25 years) and usually run the panel's full life. Mounting hardware lasts as long as the panels.