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Operations & Maintenance
Operations & Maintenance
Solar is a twenty-five-year asset with no moving parts and a slow, quiet failure mode. Nothing breaks loudly. Output drifts down — from soiling, from a failed bypass diode, from a string that has gone open circuit, from an inverter derating itself in heat — and unless somebody is measuring, a system can lose a fifth of its generation for a year before anyone notices the bill stopped improving.
That is what maintenance is for. Not repair; detection.
First: you may already have five years of it, free
If your system was installed under PM Surya Ghar, the scheme guidelines require the registered vendor to provide five years of comprehensive operation and maintenance free of cost from the date of commissioning. This is not a goodwill gesture and it is not optional — it is a condition of the vendor's registration.
Within that period:
- Repairs and maintenance are free of cost under the Comprehensive Maintenance Contract.
- Non-performing or under-performing components are repaired or replaced at no charge — note that under-performance, not only outright failure, is covered.
- Original equipment manufacturer warranties pass through to you, the consumer.
Separately, module manufacturers must warrant against manufacturing defects, material quality defects and non-conformity to specification for not less than five years from commissioning, with repair or replacement at no cost to the end consumer.
Alongside this, MNRE can inspect installed plants, and non-standard, non-functional or non-compliant systems can lead to de-registration of the vendor and penalties. At least 1% of installed systems nationally are subject to independent third-party assessment.
If you are inside five years and are being invoiced for routine maintenance on a subsidised system, ask which clause it is being charged under. We would rather you know that and never become our customer than not know it.
What performance you are entitled to expect
The MNRE specification sets the module degradation floor, and it is the yardstick to hold a system against:
| Period | Minimum retained output |
|---|---|
| Year 1 | above 97% of nominal |
| Through the first 10 years | above 90% of rated STC output |
| Through the following 15 years | above 80% |
| Annual degradation | below 0.5% |
A system that is generating materially below that curve, once soiling and weather are accounted for, has a defect — and inside five years, that defect is the vendor's to fix at no charge.
How to tell whether your system is underperforming
Every compliant inverter has built-in SIM or dongle data communication, so generation data exists whether or not anyone reads it. Three checks catch most problems without any instrument:
- Compare like months, not consecutive months. March against last March. Solar output varies seasonally by far more than most faults do, so month-on-month comparison mostly measures the calendar.
- Watch the shape of the day, not the total. A clean array on a clear day traces a smooth curve. A notch in the middle is shading. A flat top is the inverter clipping or derating. A curve that starts late and ends early is usually obstruction, not weather.
- Read the string balance. On a multi-string inverter, strings of equal size and orientation should track each other closely. One string persistently low is a fault with a location.
On the bill side, remember that your DISCOM bill must show units injected, units supplied, net billed units and the export balance carried in and out. Those fields are a monthly generation record you are already being sent.
Cleaning, and the honest version of it
Soiling is the largest recoverable loss on most rooftop systems in Madhya Pradesh, and dust is seasonal rather than uniform: the dry pre-monsoon months load panels fastest, the first heavy rains clean them well, and the post-monsoon and winter period is comparatively slow.
That argues for cleaning on a cadence tied to the season and the site — a plant beside an unpaved approach road or near cement, stone or agricultural processing soils far faster than a suburban rooftop. Cleaning is done with water and a soft brush, in the early morning or evening. It is not done with detergent, not done with anything abrasive, and not done at midday, when cold water on hot glass risks thermal stress.
Two warnings worth stating plainly. Do not walk on modules — micro-cracks in cells do not show and reduce output permanently. And do not power-wash at close range, which drives water past the frame seals.
What a maintenance contract should actually contain
After year five, or on a system we did not install, an annual contract is worth having if it specifies what will be measured. A contract that promises "regular maintenance" without deliverables is difficult to hold anyone to. The elements that matter:
- Scheduled cleaning, at a cadence matched to the site's soiling rate.
- Inverter inspection — ventilation, filters where fitted, fault-log review, firmware currency, and thermal check of the enclosure.
- DC and AC inspection — connector integrity, cable support and UV exposure, string open-circuit voltage and operating current against expectation, and torque check on structural fasteners.
- Earthing and protection testing — earth resistance, surge protection device status, and confirmation that anti-islanding still functions. These are the checks that are about safety rather than yield, and they are the ones most often skipped because nobody misses them until they matter.
- Structural inspection — corrosion at fixings, ballast or anchor condition, and roof penetration seals.
- A written performance report, benchmarked against the same period last year and against the degradation curve above, naming what was found and what was done.
Ask for the report even in a year where nothing is wrong. A record of normal is what makes an abnormal reading legible later.
Our scope
Scheduled cleaning · inverter and string inspection · DC/AC wiring and earthing audit · protection verification · structural and fastener check · remote performance monitoring · benchmarked written reporting · fault response.
We maintain systems we installed and systems installed by others. On a third-party system the first visit is an assessment, because a contract written before anyone has seen the plant is a contract written about an imagined one.