Module product warranty against performance warranty, the shorter inverter term, workmanship cover, and the gap that the building's own fire and property policy is likely to leave open.
Two documents get confused in almost every tender we read. A bidder writes that the modules carry a long warranty, the committee ticks the box, and nobody notices that two different promises with two different durations have been collapsed into one line. When a module underperforms in year nine, that difference is the whole claim.
A product warranty covers the thing: defects in materials and workmanship, delamination, frame failure, a junction box that fails, corrosion beyond what the standard permits. A performance warranty covers the output: a guaranteed remaining percentage of rated power at stated years, usually a first year allowance and then a straight line annual degradation limit thereafter. The performance term is the longer of the two on almost every datasheet, which is why quoting only the longer number is misleading.
| Product warranty | Performance warranty | |
|---|---|---|
| What it covers | Defect in the module itself | Power output falling below the guaranteed curve |
| What a claim needs | Evidence of the defect and the serial numbers | A measurement against the curve, usually flash test or on site test under stated conditions |
| Typical remedy | Repair, replacement or refund at the manufacturer's option | Supply of additional modules or compensation to make up the shortfall |
| Who pays freight and labour | Frequently excluded, so read the clause | Frequently excluded, so read the clause |
| What voids it | Unapproved mounting, mechanical load beyond the rating, unsuitable environment | The same, plus failure to keep operating records |
Two clauses inside module warranties deserve reading in Bangladesh specifically. The first is the mechanical load and mounting clause: install outside the manufacturer's clamping zones or exceed the stated load and the warranty is gone. The second is the environmental exclusion, which on many warranties limits coverage for installations close to the coast or in ammonia rich air unless the module is rated for it. Neither clause will be volunteered by the seller.
Inverters carry a considerably shorter standard warranty than modules and are the component most likely to need a claim, because they contain the electronics, the cooling and the switching. Extensions are sold, and on a commercial plant they are usually worth buying, but the question that matters more is what the response looks like.
Ask for the replacement mechanism in writing. Is a failed unit repaired locally, swapped from stock held in the country, or shipped abroad? Who pays freight in each direction, who pays the labour to remove and refit, and what is the committed response time? A warranty that promises a replacement unit and delivers it in three months has cost you a season of generation. Ask the contractor what stock is held in Bangladesh, and ask the last two clients what happened when a unit failed.
The manufacturer warrants its equipment. Only the installer warrants the installation, and that is where most early faults live: water ingress at a penetration, a badly crimped connector heating up, an under sized cable, an earthing connection nobody torqued.
So a project should carry an explicit workmanship warranty from the contractor, covering the mounting structure, the cabling and terminations, the earthing and lightning protection, and the waterproofing of every roof penetration, with a defined period and defined response times. Tie retention money to it and make sure it survives at least one full monsoon.
This is the most common gap we find on operating plants. The building has a fire and property policy that was written before the roof carried a solar plant, the sum insured has never been revised, and the insurer has never been told. In that position a claim involving the array is an argument the client will not win.
Between the factory and the commissioning certificate the plant is exposed and is not yet part of anybody's property policy. Marine and inland transit cover takes it to site. Contractor's all risks or erection all risks cover protects it while it is being built, including damage caused during erection. Third party liability matters because the work is above an occupied building, and workers' cover matters because people are working at height.
Ask the contractor for the certificates before mobilisation rather than after an incident, and check that the period covers the full programme including the delay every project has.