Solar is sold on a twenty-five year horizon, which is accurate for the modules and misleading for everything else. A realistic picture requires separating the parts that last the full term from the parts you should budget to replace along the way.
How it works
Modules are the long-lived component and rarely fail outright; they decline slowly, typically around half a percent a year, which is why manufacturers warrant performance at 25 years rather than promising fixed output. The inverter is the part that will most likely need replacing once during that period. Mounting structure and cabling last the full term if they were specified properly, and are a common place for cheap quotes to save money invisibly.
| Component | Expected life | Replacement expectation |
|---|---|---|
| Solar modules | 25+ years | Rarely replaced; output declines gradually |
| String inverter | 8-12 years | Budget one replacement in system life |
| Mounting structure | 25+ years | None if hot-dip galvanised |
| DC and AC cabling | 20-25 years | None if UV-rated and correctly routed |
| Protection devices | 10-15 years | Periodic checking, occasional replacement |
Indicative service lives for typical equipment in Indian rooftop conditions. Actual life depends on product quality, installation standard, and operating environment. Confirm specific warranty terms against the products quoted to you.
The engineering view
Two different warranties are routinely conflated. The product warranty covers manufacturing defects and is often 10 to 12 years on modules. The performance warranty is a separate undertaking that output will not fall below a stated percentage by year 25. A quote advertising a 25-year warranty is almost always referring to the second one, and the product warranty term is the number worth asking about explicitly.
What this means in Karnataka
Karnataka's operating conditions are moderate for solar equipment. Coastal humidity accelerates corrosion on inadequately protected structures, and dust in drier districts increases soiling losses, but neither materially shortens module life. The dominant factor in how long a system lasts is installation quality — particularly earthing, cable routing, and whether the mounting steel was properly galvanised.
Common mistakes to avoid
Lifecycle assumptions that lead to unpleasant surprises:
- Reading a 25-year performance warranty as a 25-year product warranty
- Not budgeting for an inverter replacement around year 10
- Accepting non-galvanised or lightly coated mounting steel to reduce quote price
- Ignoring cable specification, which is invisible at handover and expensive to correct
- Assuming a warranty is useful without checking whether the brand has service presence in India
What we recommend
Ask for the product warranty term separately from the performance warranty, and confirm the inverter brand has service support in Karnataka. Then budget an inverter replacement into your lifecycle numbers from the start. A payback calculation that ignores it is understating the true cost.
Common questions
- Do solar panels stop working after 25 years?
- No. They continue generating at a reduced output. Twenty-five years is the performance warranty horizon, not a hard end of life.
- How often do inverters fail?
- Not often in a given year, but their expected life is well short of the modules', so one replacement within the system's life is normal and should be budgeted.
- What is a typical degradation rate?
- Around half a percent per year for mainstream modules, meaning output after 25 years is typically somewhere above 80 percent of the original.
- Does a warranty mean much if the brand exits India?
- Not in practice. Service presence matters as much as the warranty document, which is why the inverter brand deserves more scrutiny than most buyers give it.
- What most affects how long my system lasts?
- Installation quality, and specifically earthing, cable routing, and mounting corrosion protection. These are the parts a cheaper quote most often saves money on.
Talk to our engineering team for a solar assessment.
We will review your consumption, roof, and site constraints before recommending any capacity.