Guide · Updated September 2026
Solar maintenance: what actually matters over 25 years
The short answer
Rooftop solar needs little maintenance: periodic cleaning, and one significant replacement — the inverter, around year 10 to 12. Panels degrade by roughly 0.6% a year, which is already priced into every yield figure on this site. Budget the inverter, keep the panels clear of dust and shade, and skip the add-on services.
Cleaning: the whole job, basically
Dust is the main ongoing cost of ownership in most of India, and the fix is water and a soft brush — never a pressure washer on the glass, and never a metal scraper. In dry months every two to three weeks keeps output near peak; the monsoon does the work for you. Clean early morning or evening, when the panels are cool, because cold water on hot glass can crack it.
What degrades, and how much
Panels lose about 0.6% of their output a year — that is the figure this site uses in every generation estimate, so a 25-year projection already accounts for it. What people mistake for degradation is usually shading that grew (a new water tank, a taller neighbour, a tree), or a string that failed. If output drops faster than the annual figure, diagnose rather than accept it.
The inverter is the real replacement
Everything else on the roof has a 25-year horizon; the inverter is electronics and typically gets replaced once around year 10 to 12. That single line item belongs in your payback thinking from day one, and it is the most common thing left out of a sales pitch. Ask what an equivalent replacement costs before you sign.
The annual checks worth paying for
Once a year, verify four things: mounting bolts and structure for corrosion or looseness, DC cables and connectors for rodent damage or UV cracking, earthing and the lightning arrester, and the actual generation figure against your meter for the same month last year. If a monitoring app is part of your system, the number it shows should broadly track your DISCOM bill — if they diverge, investigate.
What not to buy
Panels are self-cleaning in the sense that rain resets them; automated cleaning robots, extended AMCs on a system with no moving parts, and annual “tune-ups” are usually priced against your worry rather than your output. The maintenance that matters is cheap: a brush, water, and a look at the inverter display.
Run your own numbers
Guides give you the rules; the calculator gives you your numbers. One input — your monthly bill.
Open the calculatorFAQ
How often should I clean my solar panels?
Every two to three weeks through the dry season, and after any long dusty spell. During the monsoon, rain handles it. Cleaning frequency is the one maintenance item with a visible effect on your bill.
Do solar panels need servicing?
No scheduled servicing in the way a car or an AC needs it — there are no moving parts and no filters. What they need is cleaning, occasional cable and earthing inspection, and eventually a new inverter.
How much does dust really cost me?
It is the largest avoidable loss on most Indian rooftops, which is why it is worth the brush rather than a service contract. Heavy dust build-up over several weeks is what turns a well-performing system into an average one.
What warranty should I expect?
Look for a 25-year performance warranty on the panels (a guaranteed output percentage, not just “no defects”) and a product warranty on the inverter — commonly around 5 to 10 years, extendable. Read whether the performance warranty is pro-rated.