Why This Is Difficult
Real tonnage savings come from specific sources, and apparent savings from others frequently move cost rather than remove it.
- Load assumptions that are more conservative than the code requires are the largest single source of avoidable steel on many projects
- Section selection against the governing load case rather than against a standard catalogue size often reduces weight without reducing capacity
- Efficient span and purlin spacing reduce the number of members, since fewer longer members can be lighter than more shorter ones
- Redundant bracing or over-specified connection detail adds tonnage without adding capacity under the load cases that govern
- Reducing steel can increase foundation demand or deflection, so savings have to be verified against the whole structure rather than the members alone
- Module loading and clamping zones constrain how far spans can be extended, so module compatibility limits the achievable optimisation
Engineering Requirements
These are the inputs required to evaluate steel consumption honestly.
- Structural calculation with the governing load cases identified, so conservation in the assumptions can be assessed
- Structure type, span, purlin spacing and tilt or rotation range, since these set the member sizes and the count
- Module dimensions, weight and clamping zone limits, since these constrain span extension
- Foundation design and the effect of structure weight on foundation demand, so savings are verified across the whole system
- Installation method and the effect of member count and weight on productivity, since lighter members are not automatically faster to install
- Coating specification, because thinner sections reduce the thermal mass available for galvanizing and can affect coating behaviour
Selection guidance: verify a tonnage saving across the whole system, not within the structure alone. Steel removed from the structure that increases foundation demand has not reduced project cost.
How We Solve It
- Load assumptions reviewed against the applicable code, so conservatism beyond the standard is identified rather than inherited
- Section sizes selected against the governing load case, allowing non-standard sections where they reduce weight
- Span and purlin spacing optimised together, since member count and member size trade against each other
- Redundant members and over-specified connections removed where the load cases do not require them
- Savings verified against foundation demand, deflection and module compatibility, so the reduction is real across the system
- Installation impact assessed, so the design remains efficient to build rather than only efficient on paper
Beyond the Structure
- Tonnage per megawatt stated in the quotation, so the buyer can see the design outcome rather than only the price
- Sensitivity to wind zone and module format provided, since both change tonnage materially and are known before design freeze
Reference Benchmarks
Benchmarks below are publicly documented industry reference projects of comparable type and scale, cited to illustrate engineering practice. They are not our delivery record.
- A 200 MW project in Spain where revising the load assumptions to the applicable code reduced tonnage without affecting the governing design case.
- A 250 MW project in the United States where span and purlin spacing were optimised together, reducing member count and installation time.
- A 150 MW project in the Middle East where a lighter structure design was verified against foundation demand, delivering a net project cost reduction rather than a structure-only saving.
Standards and Compliance
- EN 1991-1-3 / ASCE 7 snow and ice load cases matched to your design return period
- IEC 61215 / IEC 61730 for module clamping zone and frame compatibility
- EN 1090 / AISC steelwork execution classes with weld procedure qualification records
- ISO 1461 galvanizing, ISO 12944 paint systems where duplex coating is specified
- ISO 9001 production quality management, batch traceability to heat numbers
- Local building code and permitting documentation support for your jurisdiction
Quality Assurance
Every batch ships with mill certificates, coating-thickness logs and bolt records; welds follow EN 1090 or AISC execution classes. Structure warranty runs to 10 years against a 25-30 year service design life, and spare-part packages are documented so year-12 repairs do not depend on year-1 memory.
Documentation You Receive
Documentation is built for audits, not decoration: structural calculation notes stating load cases and standards used; foundation design basis mapped to your geotechnical report; material certificates for steel and fasteners; galvanizing certificates with measured coating thickness per batch; assembly drawings with torque tables; and packing documentation matched to container manifests. For financed projects we add lender-format compliance statements; for public tenders we respond to documentation schedules line by line.
Service Life and Maintenance Planning
The economics of mounting systems are decided at year eight, not at signing. Galvanizing weight, fastener coating class and edge protection determine whether the year-eight inspection finds tight hardware or rust streaks. We publish expected first-maintenance intervals by environment class and back them with batch coating records, so warranty conversations start from data.
Cost and Commercial Considerations
- Steel per megawatt is the primary driver of structure cost, so tonnage reduction is the most direct cost lever available on the structure
- Wind zone determines the achievable tonnage, so benchmarks from a low wind site should not be applied to a high wind site
- Foundation demand can rise when structure weight falls, which is why savings should be assessed at project level rather than at structure level
- Member count affects installation productivity as much as weight does, so a design with fewer heavier members can be faster than one with more lighter members
- Tonnage per megawatt should be stated in the quotation, as it makes the design outcome comparable between bidders
Frequently Asked Questions
What is a typical steel consumption for solar racking?
Where does avoidable steel usually come from?
Can we reduce steel without increasing risk?
Does a lighter structure always cost less?
How does wind zone affect tonnage?
Related Guides and Application Pages
Continue with the pages closest to your project type.
What We Need to Quote
- Design wind speed, terrain category and snow load
- Structure type, span, tilt and module format
- Foundation type, so the effect of structure weight on foundation demand can be assessed
- Installation method and any member weight or size constraints on site
Talk to a Structure Engineer
Send the design conditions and structure type, and we will return a tonnage estimate per megawatt with the load assumptions stated and the optimisation opportunities identified.
