Short answer: a ground-mounted fixed-tilt structure typically uses 30–45 tonnes of steel per MWp, rising to about 65 tonnes when steel piles are included. Single-axis trackers range from about 30 to 70 tonnes per MWp depending on design and piles. Carports need roughly two to three times as much as fixed tilt. Wind, snow, module size and foundations explain most of the spread.
Tonnes per MW is the quickest way to sanity-check a structure quote, estimate freight and compare designs. But two quotes with the same total can hide very different scopes, so the number is only useful if you know what it includes.
Key numbers
- ArcelorMittal puts typical fixed-tilt ground structures at 35–45 t/MW; PV structure suppliers commonly quote 30–45 t/MW.
- Klöckner Metals gives about 65 t/MW for fixed tilt including about 25 t of piles, and about 70 t/MW for trackers.
- Schletter states its 1P single-axis tracker uses under 30 kg/kW (30 t/MW) of steel.
1. Tonnes per MW by structure type
| Structure | Typical steel (t/MWp) | What is usually included |
|---|---|---|
| Fixed tilt, structure only | 30–45 | Posts, rafters, purlins, bracing, fasteners |
| Fixed tilt with driven steel piles | up to about 65 | As above, plus about 20–25 t of piles |
| Single-axis tracker | about 30–70 | Torque tubes, posts, bearings; piles in the higher figures |
| Hillside fixed tilt | Upper end of the fixed range | Shorter tables and more posts to follow the terrain |
| Carport | about 2–3× fixed tilt | Columns, beams and purlins for clear height and long spans |
Ranges from the published sources below; the hillside line is our engineering guidance from mountain projects in Yunnan.
2. What drives the number
- Wind and snow loads: the largest factor. A site with a basic wind speed of 40 m/s can need noticeably heavier sections than one at 25 m/s, because wind load rises with the square of speed.
- Module power per area: steel follows table area, so higher-efficiency modules lower tonnes per MW.
- Table layout: 2-in-portrait tables need fewer posts per MW than 1-in-portrait tables, but taller posts and heavier rafters.
- Foundations: driven or screw piles add steel; concrete foundations move the cost to civil works.
- Steel grade and section design: high-strength steel (S355 / Q355) and optimised cold-formed sections reduce weight for the same load.
- Terrain: slopes and uneven ground mean shorter tables and more posts.
3. Worked example: a 10 MWp project
| Structure | Steel at the range shown | 40-ft containers (about 24 t each) |
|---|---|---|
| Fixed tilt, structure only (30–45 t/MW) | 300–450 t | about 13–19 |
| Fixed tilt with piles (about 65 t/MW) | about 650 t | about 28 |
| Single-axis tracker (30–70 t/MW) | 300–700 t | about 13–30 |
Our own calculation. Steel shipments are usually weight-limited, so we plan on about 24 t per 40-ft container; the actual figure depends on the carrier and the road limits at destination. For an inland site, that is also the number of truck loads from the port.
4. How to compare structure quotes
Ask every supplier for the same breakdown, and quote on the same reference design if you can:
- Weight per table and tables per MW, so the tonnage can be checked.
- Steel grade, section sizes and thicknesses for posts, rafters and purlins.
- Coating: hot-dip galvanizing thickness or ZAM coating mass (see our material comparison).
- Whether piles, fasteners, clamps and earthing are included.
- The design loads used (wind speed, snow, seismic) and a structural calculation report.
A quote that is light per MW is not necessarily better: it may use thinner sections, a lower design wind speed or leave out piles. A heavy one may be over-designed. The calculation report shows which.
FAQ
How many tonnes of steel per MW for a solar farm?
About 30–45 t/MWp for a fixed-tilt structure, up to about 65 t/MWp with steel piles. Trackers range from about 30 to 70 t/MWp.
Do trackers use more steel than fixed tilt?
Often, but not always. Some current 1P tracker designs use under 30 kg/kW, comparable to fixed tilt, while others reach about 70 t/MW with piles.
Why do quotes differ so much in tonnage?
Different design wind speeds, steel grades, table layouts and scope (with or without piles and fasteners). Compare on the same reference design and ask for the calculation.
How many containers does a 10 MW structure need?
Roughly 13–19 forty-foot containers for a fixed-tilt structure without piles, more with piles.
How we help
Our structures plant near Kunming roll-forms profiles and galvanizes in-house. We design ground-mount, tracker and hillside structures to your site loads, and every quote states the weight per table, the steel grade and the design loads, so it can be compared line by line.
Sources: ArcelorMittal solar structures guidance on steel per MW; PV structure suppliers’ published estimates (for example PVRack); Klöckner Metals on steel for fixed-tilt and tracker projects; Schletter Group product information for its 1P tracker. The 10 MWp worked example, container planning figure and hillside guidance are our own. Related: fixed vs tracker, all mounting systems.