Grading, site roads, and erosion control

Three ways to grade, matched to the problem

Not every earthwork problem deserves the same earthwork. PVX.AI offers three grading paths, and picking the right one is usually the difference between moving a site’s worth of dirt and moving a rack’s worth.

Area grading reshapes a whole PV area to slope targets you set per direction, with cut/fill balance under your control, and can generate the site roads in the same run so the final surface, the volumes, and the roads are one consistent result. Pad grading cuts a real, level pad under each rack (and each BESS container) and seats it there, so the reveals and clearances the drawing reports are measured against the surface that will actually be built. Targeted terrain adaptation is the surgical option: it corrects the ground only under piles that miss their reveal or clearance limits while the rest of the site is held as constraints, which makes it the minimal-earthwork way to turn a failed constructability check into a compliant layout.

All three report cut and fill volumes, keep the original terrain as a hidden baseline, and feed the same cut/fill map, contours, exports, and Bill of Quantities.

Cut/fill balance: ratio slider or fill cap

PVX.AI offers two balance methods. Expand the Cut/Fill Balance section of the grading dialog and pick one. The Cut/Fill Ratio slider runs from -1 to +1 with a live diagram that updates as you drag. Centered at zero, it balances cut and fill volumes to minimize imported or exported soil. This is the classic smoothing result: material cut from the high spots fills the low spots, and the site needs little or no soil moved in or out.

Dragging the slider biases the earthwork in either direction. A cut-biased surface produces surplus material that has to leave the site. A fill-biased surface needs imported material to make up the difference. Which way you drag depends on your haulage economics: bias toward cut when exporting soil is the cheaper problem to have, and bias toward fill when importing material costs less than hauling spoil away. The live diagram shows the balance shifting before you commit to a build.

The Max Fill Height method works from a hard constraint instead of a ratio. You cap the maximum fill height, and PVX.AI produces a cut-heavy result that keeps every fill area within the cap. Limiting fill to 1 m, for example, produces a surface that minimizes fill while staying within that constraint. Use this method when your project needs a hard ceiling on fill depth rather than a target balance.

Roads engineered in the same grading run

A road that only exists as plan-view geometry tells you nothing about whether a water truck can climb it. PVX.AI generates site roads as part of the grading run: enable Generate Roads in the grading dialog, pick the site entrance points, and the road alignments are routed on the graded surface using a cost model that weighs grading effort, curvature, and drainage crossings. The road corridors are then regraded back into the surface, so the final terrain, the cut/fill volumes, and the roads are one consistent result instead of three documents that disagree.

The engineering travels with the road. Design limits like maximum grade and turn radius are derived from your grading targets and site azimuth, and every value can be edited. You set the driveable width; shoulders and side slopes are added on top, so the corridor cleared on site is wider than the lane. Mass haul is accounted with a swell factor and free haul distance. Where a road must cross a drainage channel, PVX.AI sizes the culvert from the design rainfall you specify: return period, rainfall intensity, and runoff coefficient. No design rainfall, no invented pipe diameter.

Generated roads respect road-rack setbacks, get corner rounding at every junction, and stay connected across rack-free ground. Devices placed later align to the road that serves them, and cable trenches can follow the generated roads.

Earthworks outputs

After grading, you regenerate contours from the modified surface with one command and export earthworks data as CSV. The Earthworks export pairs the pre-grading and post-grading surfaces point by point, with five columns: Northing, Easting, NGL (natural ground level), FGL (finished ground level), and Difference, where positive is fill and negative is cut. Run it after a grading operation; an ungraded site has no paired points to export.

Contour generation is under your control. The Generate Contours dialog sets the minor interval spacing and makes every Nth contour bold and labeled, with a live preview that updates as you change the values. Generated contours land on dedicated major, minor, and label layers, replacing any existing contours there, so regenerating after each grading run keeps the drawing current.

Graded terrain also exports as PVsyst-compatible CSV. Both pre-grading and post-grading variants are available, so the surface you model in PVsyst matches the surface you plan to build.

Cut/fill volumes also flow into the Bill of Quantities civil works sheet, itemized alongside site preparation, roads, cable trenches, and earthing. The Info Screen summarizes the same volumes alongside total installed DC power, pile quantities with minimum and maximum pile lengths, and the rack slope distribution.