How Long Do Solar Panels Last? Lifespan, Degradation & Warranties

Solar Panel Lifespan: 25-30+ Years

Most solar panels are warranted for 25 years of production, but they don't stop working after that. Studies of panels installed in the 1980s show they're still generating electricity 40 years later, just at reduced efficiency.

The industry standard warranty guarantees panels will still produce at least 80-85% of their original output after 25 years. Premium brands like SunPower and REC guarantee even higher output levels.

How Much Power Do Panels Lose Over Time?

Solar panels degrade at approximately 0.3-0.8% per year, depending on the panel quality, climate, and installation. This is called the degradation rate.

What Degradation Looks Like in Practice

Year 1: 100% output (some panels have a slightly higher first-year degradation of 1-2%)
Year 10: ~95% output
Year 20: ~90% output
Year 25: ~87% output (within warranty)
Year 30: ~85% output (still very usable)

Based on 0.5% annual degradation. Premium panels degrade at 0.25-0.3%.

Understanding Solar Warranties

Solar panels come with two types of warranty. Understanding both is important:

Product Warranty (Workmanship)

Covers manufacturing defects, faulty materials, and premature failure. Typically 10-15 years for budget panels, 25 years for premium brands.

Performance Warranty (Output)

Guarantees the panels will still produce a certain percentage of their rated output after a set period. Standard is 80% after 25 years. Premium panels guarantee 88-92% after 25 years.

Warranty Warning

A warranty is only as good as the company behind it. If a budget panel manufacturer goes out of business in 5 years, their 25-year warranty is worthless. This is why established brands with a track record in Australia (like LONGi, Jinko, Canadian Solar, SunPower, REC) are worth the small premium.

Inverter Lifespan: The Weak Link

While panels last 25-30 years, your inverter will likely need replacing after 10-15 years. The inverter converts DC power from your panels to AC power for your home, and it works hard every day.

String inverters (Fronius, SMA, Goodwe): 10-15 year lifespan, 5-10 year warranty
Micro-inverters (Enphase): 15-25 year lifespan, 15-25 year warranty
Replacement cost: $1,500-3,000 for a string inverter

Budget for one inverter replacement over the life of your system. Or choose micro-inverters upfront for a higher initial cost but longer warranty and lifespan.

What Affects Solar Panel Lifespan?

Heat

High temperatures accelerate degradation. Western Sydney panels (regularly hitting 40°C+) may degrade slightly faster than coastal panels. Good airflow under the panels helps. Roof-mounted panels should have at least 100mm clearance.

Salt Spray

Coastal suburbs (Cronulla, Manly, Dee Why) need salt-mist rated panels and mounting hardware. Standard aluminium frames can corrode within a few years in salt air. Ask your installer about IEC 61701 salt mist corrosion certification.

Installation Quality

Poor installation is the biggest threat to panel lifespan. Micro-cracks from rough handling, incorrect mounting angles, and bad wiring connections can all cause premature failure. Always use a CEC-accredited installer.

Maintenance

Solar panels require very little maintenance. Rain does most of the cleaning. An annual visual inspection and a professional health check every 2-3 years is all most systems need. Avoid high-pressure washing, which can damage seals.

When Should You Replace Solar Panels?

In most cases, you don't replace solar panels. They just keep producing slightly less each year. The only reasons to replace panels are:

Physical damage (hail, fallen branches, storm damage)
Manufacturing defect covered by warranty
Major upgrade (replacing old 250W panels with modern 440W panels to double your system output)
Roof replacement (panels need to come off anyway, good time to upgrade)

The 30-Year Financial Picture

Year 0: Install 6.6kW system ($6,500)
Years 1-4: Payback period (~$1,800/year savings)
Years 5-12: Pure savings (~$1,700/year)
Year 12: Replace inverter ($2,500)
Years 13-25: Continued savings (~$1,600/year)
Years 25-30: Bonus years (~$1,400/year)
Total 30-year savings: ~$43,000
Total cost (system + inverter): ~$9,000
Net benefit: ~$34,000

Bottom Line

Solar panels are one of the most durable home investments you can make. Buy quality panels from a reputable brand, use a CEC-accredited installer, and your system will quietly generate savings for decades. The only component you'll likely replace is the inverter around the 10-15 year mark.

How Long Do Solar Panels Last?