What does the Ministry of New and Renewable Energy specification say about fixing rooftop solar on a tin shed factory roof?

For tin sheds, the Ministry of New and Renewable Energy (MNRE) specification asks for a structure designed to the shed's slope, parallel to the shed or at the shed's tilt, with its lowest point more than 100 millimetres (mm) above the sheet, a base riveted to the purlin, and every structure member at least 2 mm thick.

The tin shed clauses

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.

• The structure design should be as per the slope of the tin shed.
• The inclination angle can be done in two ways: parallel to the tin shed (flat, keeping zero-degree tilting angle) if the slope of the shed is in proper south direction, or with the same tilt angle based on the slope of the tin shed to get the maximum output.
• The minimum clearance of the lowest point from the tin shade should be more than 100 mm.
• The base of the structure should be connected on the purlin of the tin shed with proper riveting.
• All structure members should be of minimum 2 mm thickness.

Rules that sit beside them

• Clause 3.5: the angle of inclination is as per site conditions to take maximum insolation and complete shadow-free operation. To accommodate more capacity the angle may be reduced until the plant meets the specified performance ratio requirements.
• Clause 3.7: the upper edge of the module must be covered with a wind shield, with slight clearance on both edges to allow air for cooling.
• Model agreement clause 2: the vendor's site survey includes a feasibility study of the roof, strength of the roof and shadow free area.

What the specification does not tell you

It sets no load limit for sheets and purlins and says nothing about corrosion of an old sheet. Ask the vendor for a written roof strength check by a structural engineer before you sign. My reading: the parallel option is tied to a shed sloping in proper south direction, so for a shed sloping another way the clause leaves only the second option. Either way, ask for a yield estimate for your own slope and orientation.

Points for the quotation

• Rivet or fixing type and count per purlin, with the purlin spacing measured on your shed.
• The measured clearance of the lowest point from the sheet, which must be more than 100 mm. Exactly 100 mm does not meet the wording.
• The member thickness list, with none under 2 mm.
• Who repairs a leaking sheet around fixings, and for how long.

What Senseible does here

Senseible reads electricity bills into monthly records, so the units you import month by month sit in one place. It does not check roofs or structures.

• Flat roof solar: ballast or anchor bolts
• Raised solar structure: sizes by height
• Wind damage to rooftop solar: who pays
• Solar on a rented factory roof

Sources: Ministry of New and Renewable Energy (MNRE), Guidelines for PM-Surya Ghar: Muft Bijli Yojana, Central Financial Assistance to Residential Consumers, with Annexures 2 to 4

Last reviewed 2026-11-06. Re-check clause numbers and figures against the current version of the guidelines before you rely on them. Clause numbers are from Annexure 3, section 3.12 (ii). Roof strength is for a structural engineer to confirm.