Do solar modules on a dairy, coastal or chemical factory roof need extra corrosion tests?
The Ministry of New and Renewable Energy (MNRE) specification says modules used in a highly corrosive atmosphere throughout their lifetime must qualify to the salt mist corrosion standard. It also lists an ammonia corrosion test for sites like dairies and toilets, and a test for potential-induced degradation.
What the specification says
These are clauses from the technical specification in Annexure 3 of MNRE's guidelines for its residential rooftop solar scheme, Pradhan Mantri Surya Ghar: Muft Bijli Yojana. A factory is not bound by them, but they are a published checklist to hold a quotation against.
- Clause 1.2: for the photovoltaic (PV) modules to be used in a highly corrosive atmosphere throughout their lifetime, they must qualify to IEC 61701 or IS 61701, where IEC is the International Electrotechnical Commission and IS the Indian Standard.
- The standards table names IS/IEC 61701 as salt mist corrosion testing.
- The same table names IEC 62716 or IS 16664 as ammonia (NH3) corrosion testing, as per the site condition like dairies, toilets etc.
- Modules must also pass IS 17210 Part 1 or IEC 62804-1, the test for potential-induced degradation.
Other parts that face the same air
- Structure bolts, nuts and fasteners shall be of stainless steel grade SS 304 or hot dip galvanized, and structural material shall be corrosion resistant.
- Aluminium structures need protection towards rusting by coating or anodization.
- Array junction boxes and the direct current distribution box: protection of IP 65 or better. Alternating current distribution panels: IP 54 or better indoors and IP 65 or better outdoors. IP stands for ingress protection.
Which of your sites count
The specification does not define a highly corrosive atmosphere. My reading is that a seafood unit on the coast, a chemical unit with acid or chlorine fumes, and a dairy or cattle shed with ammonia in the air are the cases the two tests were written for. A dry inland assembly unit is not. When in doubt, ask the module maker in writing whether the model carries a salt mist or ammonia test report, and put the report number in the quotation.
What to ask the vendor
- The test report for IEC 61701 and for IEC 62716, with the laboratory name and date, for the exact model quoted.
- A statement of which corrosion class the maker rates the model for.
- Whether the warranty is reduced for sites near the sea or near ammonia sources. The model agreement is silent.
What Senseible does here
Senseible reads fuel invoices and electricity bills into monthly records, so your monthly grid units are on file. It does not test modules or rate a site's air.
- Datasheet checks before you accept modules
- Output guarantee over 25 years
- Does the ALMM rule apply to factory rooftop solar
Last reviewed 2026-11-06. Re-check clause numbers and figures against the current version of the guidelines before you rely on them. Standards are revised, so check the current edition and the maker's own test reports.