A daytime sewing shift can align well with solar generation, but weekends, overtime, ventilation and production changes affect actual self-consumption. Assess the energy case alongside the factory's specific buyer-reporting requirements.
What the roof can realistically offset
Worker count does not establish electrical demand or the right PV capacity. Measure the sewing floor, compressed air, ventilation, lighting and other loads over representative shifts. Model direct use and export across the year.
Beyond the electricity bill, a solar project can contribute to a factory's energy and sustainability programme. Agree the relevant LEED or EDGE assessment and buyer reporting requirements before deciding what to measure and include in the project handover.
Input
Evidence needed
Why it matters
Consumption
Twelve months of bills and representative interval demand
Separates direct use, exports and changing demand.
Generation
Location, layout, weather dataset and loss assumptions
Estimates output month by month.
Connection
Sanctioned load, transformer and utility requirements
Establishes eligible capacity and approval conditions.
Installed cost
Dated itemised quotation and exclusions
Includes roof work, connection and commissioning.
Operating cost
Maintenance, insurance and replacement assumptions
Avoids treating later electricity as cost-free.
Confirm the connection's current eligibility and capacity limits with the utility using the sanctioned-load and transformer documents. Distinguish inverter AC capacity from module DC capacity.
What solar earns you with buyers and certifiers
LEED assessment: ask the project's certification adviser which rating-system version, credit requirements and renewable-energy contribution apply. Solar installation alone does not establish the certification outcome.
EDGE assessment: confirm how the proposed solar generation enters the project's energy model and the documentation the assessor requires.
Buyer reporting: confirm each customer's current reporting requirements and the evidence it accepts for renewable electricity. Requirements differ between buyers and programmes.
Emissions reporting: retain generation records and document the calculation method, reporting period and treatment of renewable-energy claims.
Certification is where the commissioning paperwork stops being an administrative afterthought. An auditor will ask for metered generation data, not an invoice for a solar plant. Specify a monitoring platform that logs and exports generation at the level of detail your certification body wants, and make sure the handover pack includes the commissioning test records, the module and inverter datasheets with their IEC certification numbers, and the signed structural certificate. Assembling that a year later, from a contractor who has moved on, is painful.
CGI on steel trusses: the structural question
Assess the exact roof profile, structure, fixings and condition. Some standing-seam systems allow approved non-penetrating clamps; ordinary corrugated sheet must not be assumed to accept the same detail. Verify the complete structural load path and waterproofing design.
Older buildings are the harder case. A factory that has been extended twice will have roof planes of different ages, different purlin spacings and different degrees of corrosion at the fixings, and each needs its own assessment. Where a roof is at the end of its life, the honest answer is to re-sheet before mounting rather than to fit a 25-year asset onto sheeting with five years left in it. A contractor willing to say that before contract is worth more than one who says it afterwards.
Approval and the connection path
Use the supplying utility named on the factory bill. Obtain its current application requirements; geographic shorthand is not enough to identify every industrial connection.
Identify the supplying utility from the bill and obtain its current application and equipment requirements.
Complete the load, roof, structural and connection assessment and submit the required documents.
Obtain the required pre-installation approval before committing to the final installation.
Install and test the approved design through qualified personnel.
Complete utility inspection, metering and the signed agreement before authorised export accounting begins.
What goes wrong on RMG roofs
Shading from the neighbours. Factories in dense industrial belts sit close to taller buildings, water tanks and stair towers. A shading study run across the year, not on one afternoon, is what tells you which roof planes are worth using and where string boundaries should fall.
Rooftop clutter. Exhaust fans, AHUs, water tanks, dining sheds and prayer spaces occupy roof that a satellite image shows as clear. Survey it through a safe access plan that addresses fragile areas and fall protection.
Roof leaks from bad mounting. Water over a cutting floor or a finished goods store is a production loss, not a maintenance ticket. Insist on the mounting detail drawing and the sealing specification.
Harmonics and generator interaction. Compressors, drives and an existing standby generator all sit on the same board as the inverters will. Measure power quality at the main panel before design, and get the anti-islanding and changeover arrangement onto the SLD.
Dust and monsoon soiling. Yield modelling that ignores Bangladeshi soiling is optimistic. Agree the cleaning frequency and who carries it out before the O and M contract is signed.
What to ask an EPC contractor before signing
What performance ratio are you guaranteeing, and what is the remedy if it is missed? A number with no consequence attached is not a guarantee.
Are structural design, lightning and surge protection, earthing, monitoring and the net-metering application inside the price? These are the five items most often quoted as extras later.
Which module and inverter makes are proposed, and is there service presence in Bangladesh? Compare the exact models, warranties, documentation and the support arrangement available for the offered equipment.
What documentation will I receive at handover for the agreed LEED, EDGE or buyer reporting requirements? Ask for the list before award.
What is the O and M scope and the response time for an inverter fault? A week of a dead inverter in March is a measurable loss.
Can I visit a commissioned plant on a comparable roof?
Plan the solar installation around factory operations
For an RMG factory, the proposal needs to fit both the electricity profile and the production schedule. Bring facilities, electrical and production staff into the review so roof works, cable routes, shutdowns and future building changes are considered before a capacity is agreed.
Share shift schedules, holiday closures, interval load data and expansion plans. Ask how the estimate changes when sewing lines run late or production is reduced.
Provide roof drawings, repair history and access details. Agree structural review, roof-work responsibilities, safe maintenance access and the installation sequence with the factory team.
Specify the generation records your customer or certification reviewer requests. Confirm monitoring access, exportable reports, handover documents and who maintains those records after commissioning.