Rooftop Solar Structural Frames and BOS Manufacturing Facility

Project Overview

An Indian steel and electrical engineering major and a European solar mounting technology partner engaged IMARC Engineering to establish a greenfield rooftop solar structural frames and balance-of-systems (BOS) manufacturing facility at Bhavnagar, Gujarat. The project was structured against the Government of India's PM Surya Ghar Muft Bijli Yojana — launched by Prime Minister Narendra Modi on 13 February 2024 with Cabinet approval on 29 February 2024 and a total outlay of INR 75,021 Crore, targeting the installation of rooftop solar systems in one crore Indian households by March 2027, providing up to 300 units of free electricity per month and up to 60 percent Central Financial Assistance for the first 2 kW capacity and 40 percent for the third kW subject to a cap of INR 78,000.

The scheme's structural demand pull is validated by the freshest MNRE reporting: cumulative residential rooftop solar capacity under PM Surya Ghar reached 16.25 GW as of 2 September 2026, with over 50 lakh households benefiting as of July 2026 — the scheme is now benefiting one lakh households every six days, with installation pace accelerating to approximately 16,328 installations per day in July 2026 (a 3.2-fold increase from 5,038 per day in October 2025). India's total non-fossil installed power capacity crossed 300 GW as of 31 July 2026 including 164.59 GW of solar power capacity, and the Union Budget 2026-27 allocated INR 22,000 Crore for the PM Surya Ghar Muft Bijli Yojana. The scheme is projected to create 17 lakh direct jobs across manufacturing, logistics, installation, and operations-and-maintenance, and reduce CO2 emissions by approximately 720 million tonnes over the deployed capacity lifetime. Gujarat is consistently ranked among the top-performing states under the scheme alongside Rajasthan, Maharashtra, and Tamil Nadu.

The project involved establishing 800 MW-equivalent per annum of rooftop solar manufacturing capacity across three product families — hot-dip galvanized steel structural frames for residential and commercial rooftop mounting, aluminum extrusion module frames matching Indian ALMM-listed solar PV module dimensions, and balance-of-systems electrical components covering MC4 connectors, DC and AC junction boxes, DC and AC cables, and string monitoring equipment — with approximately 24,000 tonnes per annum of steel throughput and matched aluminum extrusion throughput. Site infrastructure was designed for Phase 2 expansion adding a solar tracker line for commercial-and-industrial ground-mount solar applications aligned with the emerging Indian corporate and industrial solar deployment pipeline.

Client's Challenges

The client faced several specific challenges in establishing greenfield rooftop solar structural frames and balance-of-systems manufacturing in India:

• Multi-rooftop-type structural design: Engineering rooftop-specific structural frame designs across the diverse Indian rooftop typology — including tin-sheet, concrete-slab, tile, and metal-roof residential rooftops alongside industrial and commercial rooftop configurations — with the associated design load calculations per BIS IS 875 (structural design loads) and structural steel design per BIS IS 800, and product family variants covering the different rooftop mounting requirements.
• Hot-dip galvanization corrosion protection: Engineering hot-dip galvanization coating meeting BIS IS 4759 standards required for the 25-plus year outdoor service life of rooftop solar mounting structures, with the associated zinc bath infrastructure, pre-treatment chemistry, and quality control across the multi-variant structural frame product family.
• Aluminum extrusion for module frames: Engineering aluminum extrusion capability for solar PV module frames matching the dimensional and structural specifications of Indian ALMM-listed solar PV module manufacturers, a category where growing PM Surya Ghar demand alongside the utility-scale PLI ALMM Tranche II solar deployment creates structural demand for domestic-supplied module frame capacity.
• MNRE approved manufacturer status and BIS compliance: Achieving MNRE-approved specification compliance for rooftop solar systems required for PM Surya Ghar deployment, BIS certifications across the structural steel, galvanization, and BOS product families, and Public Procurement (Preference to Make in India) local content certification required for state implementation agency and central government procurement participation.
• Multi-state deployment logistics: Coordinating multi-state deployment logistics with distribution to state implementation agencies across the top-performing PM Surya Ghar states (with Gujarat, Rajasthan, Maharashtra, and Tamil Nadu leading installations) alongside the surrounding commercial-and-industrial rooftop solar EPC customer base and select export markets.
• Workforce build-up: Recruiting 320 personnel including steel fabrication engineers, galvanization specialists, aluminum extrusion technicians, BOS electronics assembly operators, and quality specialists in the Bhavnagar regional labour market that hosts the broader Saurashtra industrial ecosystem including the Alang steel-processing base.

What We Did

• Pre-Investment and Strategic Advisory

Our feasibility study evaluated four candidate Indian locations — Bhavnagar (Gujarat), Rajkot (Gujarat), Nagpur (Maharashtra), and Salem (Tamil Nadu) — with Bhavnagar selected on the strength of Gujarat's leading position under PM Surya Ghar (with Gujarat consistently among the top-performing states in scheme installations), proximity to the Alang steel-processing ecosystem providing structural and specialty steel supply, established Saurashtra industrial supplier network for aluminum extrusion and BOS component integration, port access through Bhavnagar and Pipavav ports for select export logistics, the Gujarat Industrial Policy incentive framework, and access to engineering talent from the surrounding Saurashtra engineering education base.

CapEx planning of INR 232 Crore covered the steel fabrication and galvanization line, the aluminum extrusion line, the BOS electronics assembly area, the quality laboratory, the warehouse, and central utilities. Financial modelling demonstrated post-tax IRR of 21.4 percent at full ramp with a 5.4-year payback.

• Engineering and Design Services

IMARC designed a 22,000 sq.m built-up facility on a 10-acre plot comprising the steel preparation and precision fabrication hall with plasma cutting, forming, and welding infrastructure for structural frame manufacturing across the residential, commercial, and industrial rooftop product families, the hot-dip galvanization line meeting IS 4759 specifications with zinc bath, pre-treatment chemistry, and finishing area, the aluminum extrusion hall housing extrusion presses and finishing infrastructure for solar module frame manufacturing, the balance-of-systems electronics assembly area for MC4 connector, junction box, and cable assembly manufacturing, the quality and testing laboratory covering structural load testing, coating thickness verification, and electrical BOS performance validation, the warehouse and outbound multi-modal logistics area, and central utilities.

Process utility design covered 5 MW grid demand supplemented by a 2 MW captive rooftop solar array using in-house-manufactured structural frames and BOS as a demonstration installation, dedicated compressed air and shielding gas supply for fabrication operations, environmental compliance infrastructure meeting Gujarat State Pollution Control Board specifications for the galvanization operations, integrated MES for lot-level and product-family-level traceability aligned with MNRE-approved specification documentation, and heavy-haul outbound logistics infrastructure for state implementation agency and EPC customer despatch.

• Procurement and Supply Chain Support

We executed a multi-geography procurement programme across 42 critical vendors. Steel plasma cutting, forming, and welding equipment was sourced from established European and Indian specialists with documented structural fabrication industry references. Hot-dip galvanization line equipment was sourced from a combination of European and Chinese specialists with proven references in the Indian galvanization industry. Aluminum extrusion press infrastructure was sourced from European and Chinese specialists. BOS electronics assembly infrastructure was sourced from a combination of Southeast Asian and Indian electronics equipment specialists. Quality laboratory equipment was sourced from European and Indian test equipment specialists.

Component sourcing was structured to maximise Domestic Content: structural steel from qualified Indian producers, aluminum billets from Indian primary aluminum producers, zinc for the galvanization line from Indian zinc suppliers, structural fasteners from qualified Indian fastener manufacturers, PCBs for BOS electronics assembly from Indian PCB fabricators, cables from Indian cable manufacturers, and specialty connector components and BOS semiconductor devices from established international specialists under structured long-term supply arrangements. Documented Domestic Content reached 82 percent in Year-1 operations and 88 percent in Year-2 as the Indian supplier ecosystem developed under PM Surya Ghar demand.

• Project Execution and Site Management

Our turnkey project management delivered 16 months from groundbreaking to first commercial dispatch, coordinating civil construction, mechanical and electrical erection, galvanization line installation, aluminum extrusion press installation, equipment integration, and phased commissioning across the steel fabrication, galvanization, aluminum extrusion, BOS electronics assembly, and quality laboratory zones.

Phased commissioning ran the steel fabrication hall first (as the critical-path bottleneck for first structural frame manufacturing), followed by the hot-dip galvanization line, then the aluminum extrusion hall, then the BOS electronics assembly area, and finally the quality and testing laboratory with progressive MNRE-approved specification and BIS certification campaigns across the product portfolio.

Multi-vendor coordination across European, Chinese, Southeast Asian, and Indian contractors required a 14-strong owner's engineering team supplemented by 6 European resident engineers from the solar mounting technology partner during the aluminum extrusion and initial product qualification phases.

• Compliance, Quality and Sustainability

IMARC led certification readiness across BIS IS 875 (structural design loads) and BIS IS 800 (structural steel), verified across the structural frame product portfolio in Year-1 of operations, BIS IS 4759 (hot-dip galvanization) verification across the galvanization line output, BIS IS 14286 (crystalline silicon PV modules) module frame compatibility verification, MNRE approved specifications for rooftop solar systems compliance across the structural, aluminum, and BOS product families, IEC 61730 (PV module safety) framework alignment, Public Procurement (Preference to Make in India) local content certification, and ISO 9001:2015, ISO 14001:2015, ISO 45001:2018, and ISO 50001:2018 management system certifications.

Environmental compliance covered Gujarat State Pollution Control Board Consent to Establish and Operate, Hazardous Waste Authorisation for galvanization process residues and pre-treatment chemistry management, and Extended Producer Responsibility commitments for end-of-life structural material recovery. The facility achieved IGBC Gold certification through 2 MW captive rooftop solar covering approximately 28.6 percent of facility daytime energy demand (with the installation itself using in-house-manufactured structural frames and BOS as a demonstration), heat recovery from galvanization line operations, variable-frequency drives across HVAC and process pump systems, and 20 percent lower facility energy intensity versus the Southeast Asian solar mounting structure manufacturing industry benchmark.

Final Results

Operational Performance

The facility achieved mechanical completion in 16 months with first commercial dispatch in month 17. Full 800 MW-equivalent per annum nameplate capacity was reached at 76 percent utilisation (equivalent to 608 MW of rooftop solar deployment supported by the plant's Year-2 output) by month 13 of operations, with sustained first-pass yield of 98.6 percent across the structural frame, module frame, and BOS product portfolio.

BIS IS 875 and IS 800 structural certifications were completed in Year-1, IS 4759 galvanization verification was maintained across the line output, MNRE approved specifications for rooftop solar systems compliance was secured across the product portfolio, and successful supplier qualification audits were passed with three state implementation agencies under PM Surya Ghar procurement, two commercial-and-industrial rooftop solar EPC customers, and one export customer across the first operational year.

Financial Outcomes

Final CapEx of INR 220 Crore delivered 5.2 percent savings against the INR 232 Crore budget through optimised civil packaging, disciplined Indian-fabrication leverage across the structural and precision utility scope, adjacency benefits from the Alang steel-processing ecosystem for scrap steel input supply optimisation, coordinated multi-vendor procurement under the Public Procurement (Preference to Make in India) framework, and Gujarat Industrial Policy incentive benefits.

Year-2 revenue of INR 305 Crore was generated at an EBITDA margin of 12 percent, consistent with established Indian solar mounting structure and BOS manufacturer reporting, supported by the PM Surya Ghar structural demand pipeline and the emerging commercial-and-industrial rooftop solar EPC customer base.

Market Access

Long-term supply commitments were signed with three state implementation agencies covering committed annual structural frame and BOS offtake against PM Surya Ghar deployment across the Gujarat, Rajasthan, and Maharashtra state programmes (all consistently among the top-performing PM Surya Ghar implementation states alongside Tamil Nadu), two commercial-and-industrial rooftop solar EPC customers covering committed offtake for corporate and industrial rooftop solar deployment aligned with the growing Indian renewable energy consumption obligation-linked demand, and one export customer covering solar structural frame supply to a Middle East rooftop solar market.

The facility positioned itself as an MNRE-approved specification-compliant preferred Indian supplier for the ongoing PM Surya Ghar scheme deployment cycle towards the one crore household milestone by March 2027, alongside strategic positioning for the successor rooftop solar programme framework.

Sustainability Impact

Our integrated design — combining 2 MW captive rooftop solar using in-house-manufactured structural frames and BOS as a demonstration installation covering approximately 28.6 percent of facility daytime energy demand, heat recovery from galvanization line operations, variable-frequency drives across HVAC and process pump systems, and LED lighting throughout, achieves 20 percent lower facility energy intensity versus the Southeast Asian solar mounting structure manufacturing industry benchmark.

Process water reclamation is delivered through closed-loop cooling and pre-treatment chemistry recovery cycles. The rooftop solar structural frames and BOS produced by the facility support Indian household and commercial rooftop solar deployment contributing directly to the PM Surya Ghar Muft Bijli Yojana 720 million tonne CO2 emissions reduction commitment across the deployed capacity lifetime, with a direct impact on rural and urban household energy affordability.

The facility holds IGBC Gold certification and operates end-of-life structural steel and aluminum material recovery partnerships aligned with the emerging Indian circular economy framework for solar sector infrastructure.

Strategic Impact

The project established a meaningful greenfield rooftop solar structural frames and balance-of-systems manufacturing capability under the PM Surya Ghar Muft Bijli Yojana framework, positioning the client across the structural demand trajectory towards the March 2027 one crore household target and the incremental capacity beyond the current 50 lakh household installed base, representing more than a doubling of the deployed rooftop solar volume over the coming 18 months alongside the growing commercial-and-industrial rooftop solar deployment pipeline.

Year-2 revenue of INR 305 Crore, MNRE approved specifications compliance across the product portfolio, three state implementation agency supply commitments, and the Middle East rooftop solar export entry led the client to approve Phase 2 expansion comprising a solar tracker line for commercial-and-industrial ground-mount solar applications aligned with the growing corporate solar deployment pipeline.

IMARC Engineering's end-to-end EPCM advisory, combining structural steel fabrication engineering, aluminum extrusion and BOS electronics integration, PM Surya Ghar scheme navigation, MNRE approved specifications compliance readiness, and disciplined multi-vendor execution — enabled the client to anchor a strategically important Indian industrial asset in a sector positioned at the intersection of India's residential decarbonisation trajectory and the accelerating rooftop solar deployment programme.