Solar and Wind Farm Site Preparation Equipment

Renewable energy site preparation in Australia is hectare-scale vegetation work sitting inside a civil program that somebody else controls. On a solar farm the clearing package covers the array footprint, internal access roads, the substation pad, cable trenches and a perimeter fence line, and it is almost always let per hectare or as a lump sum against a surveyed disturbance boundary inside an EPC contract. Wind farms are different in shape but not in commercial logic: the clearing is a string of turbine hardstands and crane pads joined by wide-radius access tracks and underground cable routes, usually priced per pad and per kilometre of track, with the tracks carrying the schedule risk because the turbine components cannot move until they are built.

What matters commercially is that the clearing contractor is rarely the critical path and is always expected to stay off it. The EPC will hold a disturbance limit that cannot be crossed, an environmental management plan that says what must be retained, and a civil crew waiting for finished ground. The attachment fleet that fits this work is the one that delivers a specified finish across large, mostly traversable areas quickly, while still handling the scattered mature paddock trees, the stumps under a future road and the discrete holes for fencing and pole lines without a second mobilisation.

The work sequence

Most renewable sites are former grazing or cropping land with scattered mature eucalypts, regrowth and shelterbelts rather than continuous forest, so the sequence is usually a mulching program with felling, grappling and stump work concentrated where the trees are. Access tracks and pads get the full chain, including compaction of trench backfill; the array footprint often only needs a mulch-in-place pass to the agreed finish.

1. Confirm the disturbance boundary and retained vegetation
2. Fell merchantable and oversize stemsWR15 or WR20 shear
3. Grapple stems to stockpile or chipperEX36 or EX40 grapple
4. Mulch remaining vegetation to finishVM-60SR, VM-65SV or HM front-mount
5. Treat stumps under pads, tracks and trenchesSC850 Pro or WE15
6. Rake and clear brash from the footprintTerragrip
7. Drill fence, pole and anchor holesTRV auger
8. Compact trench and pad backfillCPT910

How attachment changeover is planned around a sequence like this is covered in the clearing workflow guide, and it matters more on renewables than on most work because the excavator is usually shared with the civil scope.

Which attachments do the heavy lifting

Mulchers for the hectares

The array footprint is the bulk of the area and most of it is priced by the hectare, so the mulcher decides the margin. Two heads earn a quote on a typical solar site. The Shearex HM-88LV (220 cm width, 25 cm target diameter, 140 hp and above) is the one to price first for the open footprint, because on former grazing land the material is inside its target and width is what converts into hectares. The VM-40SL on a 12 to 15 tonne excavator is the one that finishes the site, working the drainage lines, batters and margins of retained trees where a front-mount carrier cannot go and should not be driven. Heavier timber on a wind farm or a wooded footprint moves the excavator head up to the VM-60SR (20 to 25 tonne, 40 cm target, 130 hp minimum), which is a different purchase rather than a bigger version of the same one. Excavator mulcher versus skid steer mulcher sets out how to split a site between the two.

Heavy tree shears for the paddock trees

Scattered mature eucalypts are the material that stops a mulching program dead, and they are better felled, recovered and dealt with as timber. The Trevi Benne WR15 (indicatively 17 to 22 tonne carriers, around 500 mm nominal cut) sits on the excavator class most civil contractors already have on a renewable site, and the WR20 (23 to 30 tonne, around 550 mm) is the answer for large-diameter hardwood. Both use a twin-blade system with rotation options, and the optional fork tower helps control a heavy stem while it is placed for the grapple. Whether a shear or a mulcher should take a given stand is a recovery decision, covered in mulcher versus tree shear.

Forestry grapples and the Terragrip for stems and brash

Felled stems have to go somewhere, and on a renewable site that is usually a stockpile at the boundary or a chipper feeding a biomass or mulch outlet. The Powerhand EX40 forestry grapple (20 to 30 tonne, 0.40 m², 2,137 mm opening, 1,091 kg with rotator) moves whole hardwood stems and big bundles; the EX36 (16 to 25 tonne, 0.36 m²) suits the same carrier as the WR15. The Terragrip (around 14 to 25 tonne) is worth a serious look here because renewable footprints need raking and root ripping after felling, and its fixed rake leg with a single gripping leg does that clean-up without a changeover.

Stump tools where the civil works follow

Stumps left under an array can often stay processed below grade, but stumps under a turbine hardstand, a crane pad, an access track or a cable trench are earthworks defects. The Dipperfox SC850 Pro (13 to 30 tonne, 850 mm stump, 900 mm depth, 43,000 Nm first-gear torque) processes large stumps in place with a contained footprint, which suits the array area and fence lines. Where the geotechnical specification requires the root mass out of a pad or trench alignment, the Trevi Benne WE15 (20 to 28 tonne, 1,400 mm jaw, 2,240 kg) cuts the roots, extracts and splits the stump for stockpiling. Stump grinder versus stump cutter explains which outcome each delivers.

Augers and compactors for the ground-preparation scope

Renewable sites contain thousands of discrete holes: perimeter fence posts, pole lines, sign posts and anchors, often on sloping wind farm ground where an excavator-mounted OMEF TRV auger drive is more stable than a small dedicated unit. Cable trenches and pad edges need compaction where a roller cannot reach, which is what the OMEF CPT910 (12 to 20 tonne, 900 kg, 50 to 100 L/min) and CPT425 (5 to 9 tonne) are for. Taking these scopes keeps the carrier earning after the last tree is down.

Carrier size and fleet composition

The natural core of a renewable clearing fleet is the 16 to 25 tonne class, because a 20 tonne excavator has a published model in every family the job needs and then goes back to the civil scope on the same site, which is where the attachment case is actually made. Heavy hardwood pushes the felling and extraction carrier into the 25 to 40 tonne class. The hectare work belongs to a skid steer, compact track loader or dedicated carrier running an HM head, with a 10 to 16 tonne machine and a VM-40SL finishing the drainage lines and edges it cannot reach. Remote sites make transport a real cost, so read the transport and mobilisation guide before committing to a 30 tonne float.

Site and commercial factors that change the equipment choice

The environmental approval defines the job. Renewable projects usually carry conditions on retained trees, hollow-bearing trees, riparian buffers and offset areas, so mulching selectivity and the ability to fell a single tree without damaging its neighbour become specification items rather than preferences. A project approval is not the same thing as permission to clear a particular hectare, so the contractor needs to know which approvals the developer holds, what the environmental management plan protects and who decides when a boundary is in doubt. Ask the developer and the relevant state agency, using native vegetation approvals as the question list.

Scattered hardwood raises stem mass more than the diameter suggests, which matters on a site where trees are felled and carried rather than reduced; see the Australian hardwood guide. Most renewable sites are hot, flat and dusty, which is the worst environment for hydraulic cooling on a mulcher running under continuous load; hydraulic cooling and heat explains what to check on the carrier. Grassland sites are also where a mulcher is most likely to be stood down, on the say-so of the relevant state fire authority and the developer’s own conditions; the fire risk guide covers housekeeping and suppression. Remoteness dictates the parts strategy: carry teeth, blades, belts and a centre screw on site. Finally, agree the finish class and the material fate early, because a change from rough knockdown to fine finish, or from mulch-in-place to recover-and-remove, can double the machine hours.

Measuring and pricing production

Run the trial on a representative block that includes the scattered trees, not just open regrowth, and record separately: net hectares mulched per productive hour by pass, stems felled with a diameter distribution, stumps processed per hour by size class, and the number of holes drilled per hour on the actual soil. Record fuel and tool wear per hectare because they move with the finish specification.

As an illustration only, assume a front-mount head and carrier at an internal cost of $220 per hour, a measured first pass of 1.0 hectare per hour and a second finishing pass of 0.6 hectares per hour. The effective rate is 1 divided by (1 plus 1.67), or about 0.37 hectares per hour, giving roughly $590 per hectare before mobilisation, tooling and margin. If the specification only needs the first pass the same machine costs $220 per hectare, which is why the finish class must be in writing before the tender goes in. The building a tender rate guide and the cost per unit calculator take these numbers through utilisation and wear.

Before you tender or buy for this work

• Obtain the disturbance boundary, retained-tree register and environmental management plan before pricing a hectare.
• Walk the footprint and record stem density and a diameter distribution for the scattered trees, separately from the regrowth.
• Agree the finish class (knockdown, standard mulch, fine finish) and whether material is mulched in place or recovered.
• Confirm which stumps must be extracted (pads, tracks, trenches) and which may be processed below grade.
• Check the carrier lift chart at working radius for the heaviest head plus rotator plus hitch, particularly a WR20 or WE15.
• Confirm continuous auxiliary flow, pressure, case drain and cooling capacity for a mulcher running all day in summer.
• Ask whether native vegetation approvals apply and who holds them, and what the fire-danger stop conditions are.
• Price transport for the largest carrier and the front-mount unit to a remote site, including permits.
• Establish exclusion zones and WHS procedures for felling and mulching near the civil crews sharing the site.

Frequently asked questions