AI Should Not Do Engineering Work
Software that blurs the line between drafting and engineering puts projects at risk. Here's why we built a tool that deliberately stops short of engineering — and why that restraint matters.
AI Should Not Do Engineering Work
There's a trend in solar software that should concern every engineer: tools that quietly cross the line from drafting into engineering, making decisions that belong to licensed professionals.
Panel layout optimization that picks string configurations. Wire routing that selects conductor sizes. Automated permit packages that stamp out calculations without an engineer reviewing the inputs. These get marketed as time-savers. And they are — right up until they're wrong.
The Line Exists for a Reason
Engineering is judgment. A PE recognizing that wind exposure changes structural requirements. An electrical engineer upsizing a conductor beyond NEC minimum because the voltage drop on a 300-foot homerun warrants it. An experienced designer noticing the proposal tool placed modules over a gas line easement nobody flagged.
These decisions require context no software has, experience no algorithm replicates, and a human who will be held professionally and legally accountable for what gets built.
Drafting is different. Drawing polylines along string paths. Routing homeruns. Measuring cable lengths. Placing tags. This work is repetitive and time-consuming. It does not require engineering judgment — it requires CAD proficiency and patience.
The distinction isn't arbitrary. It's the difference between deciding what to build and documenting what was decided.
The Danger of Plausible-Looking Output
The most dangerous outputs in solar engineering are the ones that look correct but aren't. A proposal tool that auto-generates a stringing plan can produce something that passes the eye test. The strings connect to inverters. The voltage windows appear to check out. But the software didn't consider the installer's preferred stringing direction, the site-specific access requirements, or the AHJ's one-off conduit fill rule.
When humans shift from doing work to reviewing the work of a machine, error-detection rates drop. Researchers call this automation complacency — a well-documented phenomenon across aviation, nuclear power, and medical devices where human operators over-trust automated systems and miss errors they would have caught doing the work themselves. In solar, the consequences are rework costs, permit rejections, and liability exposure. Not life-threatening, but expensive and avoidable.
Per NEC Article 690, solar PV system design requires compliance with voltage window calculations (690.7), overcurrent protection sizing (690.9), and conductor ampacity (690.8) — decisions that depend on site-specific conditions a PE must evaluate.
What Engineers Actually Want Automated
Ask a solar engineer who's been doing C&I projects for five years what they want automated. The answer is remarkably consistent: the drawing part, not the thinking part.
They don't want software deciding how to string their project. They want software that takes their stringing decisions and draws the polylines, routes the homeruns, and exports the cable lengths — in seconds instead of hours.
The irony is that by automating drafting correctly — and only drafting — you make the engineering better. An engineer who isn't exhausted from eight hours of drawing polylines has more mental bandwidth to catch design issues, question assumptions, and call the AHJ to clarify ambiguous requirements.
Why We Built It This Way
Leaf automates drafting in AutoCAD. We accept engineered inputs and produce drafting objects. Strings, homeruns, cable lengths, tags.
We don't optimize panel layouts. We don't size conductors. We don't generate engineering calculations. Not because we couldn't attempt those features, but because we're engineers ourselves and we know those are the wrong things to automate.
The next time a software vendor tells you their tool "automates solar design," ask one question: which decisions is this software making on my behalf?
If the answer is "none — it executes the decisions you've already made," that's a drafting tool. If the answer involves string configuration, conductor sizing, or code compliance — you need to understand exactly how it's making them and whether you're comfortable putting your stamp on output you didn't create.
Leaf automates drafting in AutoCAD — strings, homeruns, cable lengths, and tags. The engineering stays with you. Start a 14-day free trial — no credit card required.