Mounting systems can look near-identical in a brochure and behave very differently once site exposure, array geometry and support spacing are taken into account. Two quotations for the same plant can differ mainly because they assumed different wind criteria, layouts or foundation conditions, not because one is more efficient.
Before procurement is finalised, find out which inputs each supplier used and which checks are still open.
Questions to ask each supplier
A quotation is only comparable with another when its inputs and scope are understood. Price differences often reflect different assumptions rather than different efficiency.
- Which site, layout revision, tilt, height and support spacing does the offer assume?
- Which wind criteria and load combinations were used, and where did they come from?
- Is the proposal preliminary, or based on final project information?
- What is included: calculations, fabrication drawings, connection details, foundation reactions, installation guidance?
- Who supplies the foundation and geotechnical inputs, and what ground conditions are assumed?
- What corrosion protection is specified, and for which exposure?
A procurement-readiness check
Before releasing fabrication or placing the order, close the inputs that affect the design and identify which documents are still subject to approval. Keep preliminary options visibly separate from approved-for-construction information.
If the supplier uses a standard configuration, ask how departures from it will be reviewed and who authorises the final project-specific design. That protects the programme from changes after steel is cut or site work has started.
- Confirm outstanding technical queries and their owners.
- Agree the revision and change-control process.
- Check delivery interfaces with civil and installation teams.
- Obtain project approval before final release.