How to Automate Solar Construction Documents in AutoCAD

If you produce solar construction documents in AutoCAD, you know the workflow. Panel groups get defined. Strings get drawn one by one, checking voltage windows as you go. Homeruns get routed from string endpoints back to inverters. Then you measure every cable run with DIST, type the numbers into a spreadsheet, and place tags throughout the drawing.

None of this is engineering. It's drafting — repetitive, time-consuming, and identical in structure from project to project. The engineering decisions (inverter selection, string sizing, wire gauge, code compliance) are already made before you start drawing.

This post covers what it looks like to automate that execution.

What "Automation" Actually Means Here

Not a black box that produces finished permit packages. Construction documents require engineering judgment that tools shouldn't be making.

What we mean is purpose-built commands that understand solar design context and execute the repetitive drafting steps that follow predictable rules. If panels are grouped and a voltage window is defined, valid string configurations can be computed and drawn. If string endpoints and inverter positions are known, homerun paths can be routed. If polylines exist, their lengths can be measured and exported. If strings have metadata, tags can be generated.

Each step follows deterministic logic. The tool accepts engineered inputs and produces drafting output. We do the drafting, you do the engineering.

Step-by-Step: Automated Workflow with Leaf

The entire sequence runs in roughly 3 minutes once you know the workflow.

Step 1: Panel Group Creation — PANELGROUPCREATE

Select panels that belong together (same roof plane or array section) and run PANELGROUPCREATE. This associates them into a group with metadata. Your decision: which panels should be grouped together.

Step 2: String Solving — SOLVE

SOLVE takes your panel groups and inverter specifications, computes valid string configurations, and draws string polylines as intelligent CAD objects carrying XData — panel assignments, inverter mapping, string number. Every string is electrically valid for the specified inverter. Your decision: the inverter model and its specifications.

Step 3: Inverter Placement — ADDALLINVERTERS

K-means clustering determines optimal inverter positions relative to string endpoints, minimizing total cable distance. Your decision: accept the optimized positions or move inverters based on structural, accessibility, or customer requirements.

Step 4: Homerun Routing — HOMERUNS

Routes cable paths from each string endpoint to its assigned inverter with clean 90-degree geometry. Replaces the most tedious part of the manual workflow. Your decision: review and adjust any routes that don't work for your site conditions.

Step 5: Cable Export — CABLEEXPORT

Measures every polyline and exports string data, cable lengths, and circuit information to CSV. No DIST command. No spreadsheet typing. Your decision: using those lengths for wire sizing, voltage drop analysis, and material takeoffs.

Step 6: Tagging

Generates and places string tags, circuit identifiers, and equipment labels from the metadata already associated with each CAD object.

What Changes

The engineering workflow doesn't change. You still choose inverters, size wires, navigate code requirements, review and stamp documents.

What changes is the drafting. Hours become minutes. And rework stops being painful — when a design changes, delete and rerun. Three minutes later, updated construction documents reflecting the new design. Engineers stop dreading changes when changes are cheap.

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Ready to automate the repetitive parts of your CD workflow? Start a 14-day free trial of Leaf and run your next project through in 3 minutes.