“Free solar design software” sounds great until the hardware add-ons add up, project caps kick in, or the simulation depth turns out to be too thin for the project you actually need to ship. This guide walks through every genuinely free option in 2026, names the catches, and explains when SurgePV’s flat-priced plan is the better deal.
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The Truly Free Options in 2026
OpenSolar Free Tier
The most popular free tier in the production design category. Works for small residential roofs at low volume. Add-ons stack quickly at C&I or once hardware integrations come into play. Realised cost typically clears $1,000 per user per year at 5+ projects per designer per month.
SAM (System Advisor Model, NREL)
NREL’s free open-source research tool. Excellent for sensitivity studies, parametric analyses, and learning the engineering fundamentals. Not built for production EPC workflow. No integrated proposal, no AutoCAD export, no CRM integration.
PVWatts (NREL)
NREL’s free quick-estimation tool for residential yield. Simplified hourly model. Good for back-of-envelope checks at the lead-qualification stage. Not sufficient for bankable yield reports.
SurgePV Free Trial
Full-feature solar design platform free trial with no credit card required. Includes AI 3D roof modeling, 8,760-hour shading, bankable yield, financial modelling, AutoCAD export, and branded proposals. Time-limited as a trial, then transitions to a paid plan.
Aurora Solar Free Trial
Limited trial of Aurora Solar. Typically excludes AI Mode and Sales Mode. Time-limited.
HelioScope Free Trial
Limited trial of HelioScope. Project-count restricted; see HelioScope pricing for what the paid tiers unlock.
What “Free” Actually Costs
| Tool | Headline | Hidden cost | Realised total |
|---|---|---|---|
| OpenSolar free | $0 | Hardware fees, paid extensions | $0 to $1,800 / yr per seat |
| SAM | $0 | Not production-grade | Missing workflow tools |
| PVWatts | $0 | Simplified model | Insufficient for bankable |
| SurgePV trial | $0 (trial) | Trial period limit | Transitions to $1,299 to $1,899 / yr |
| Aurora trial | $0 (trial) | Trial limits | Aurora paid plans needed |
When Paid Is Cheaper Than Free
The realised cost of free + add-ons + missed engineering depth crosses paid flat-rate platforms at roughly 5 projects per designer per month. At that volume, SurgePV’s flat $1,299 to $1,899 per user per year is the cleaner choice.
Cost: Free Tier vs SurgePV at Team Size
| Team size | OpenSolar free realised | SurgePV plan |
|---|---|---|
| 1-seat solo | $1,000 to $1,800 per year | SurgePV Individual: $1,899 per year |
| 3-seat team | $3,500 to $6,000 per year | SurgePV 3-User Team: $4,497 per year |
| 5-seat team | $6,000 to $10,000 per year | SurgePV 5-User Team: $6,495 per year |
At any team size past pure solo small-residential, the SurgePV flat plan matches or beats the realised cost of free + add-ons while including bankable simulation and integrated proposals.
What You Get When You Upgrade From Free to SurgePV
- AI 3D roof modeling from satellite in under 60 seconds
- Clara AI natural-language design assistant
- Full 8,760-hour module-level shading on every paid plan
- Bankable P50, P75, P90 yield reports
- Solar financial modeling with country tariffs (PM Surya Ghar, SREC, FiT)
- DXF/DWG export for AutoCAD handoff
- Branded solar proposals with e-signature in 9 languages
- QuickEstimate pairs as the sister CRM
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Who Should Use Each Free Option
- Use OpenSolar free if pure small residential is your entire scope and add-ons stay near zero.
- Use SAM for sensitivity studies and engineering education.
- Use PVWatts for quick lead-qualification yield checks.
- Use the SurgePV free trial if you are evaluating a production-grade platform on a real project.
If Free Is Not Enough, Start Here
The free tiers work until your project mix outgrows them. Depending on which constraint you hit first, these are the guides that pick up where the free options stop:
- Hit the accuracy ceiling on shading or yield? Start with photovoltaic design software and PV yield simulation software.
- Need a browser platform without an install? See the online solar design tool comparison and cloud solar design software.
- Losing deals on the customer document? See solar proposal software.
- Designing homes at volume? See residential solar design software.
- Selling in India under PM Surya Ghar? See solar design software India for IS code, ALMM, and INR pricing coverage.
The Bottom Line on Free Solar Design Software
For pure small residential at low volume, OpenSolar free can be the right choice. For everything else, paid flat-rate platforms like SurgePV are almost always cheaper on realised total cost, and they ship the engineering depth, bankable simulation, and integrated proposal stack that free tiers do not. For a full field comparison, see our best solar design software ranking. Whichever design tool a residential installer settles on, Qbits’ residential solution and full product catalog cover the hardware side of that same small-residential segment.
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Book a Free DemoFrequently Asked Questions
What is the best truly free solar design software in 2026?
Is OpenSolar really free for solar installers?
Can SAM (NREL) replace paid solar design software?
Is PVWatts free and how accurate is it?
When is paid solar design software cheaper than free?
Does SurgePV offer a free trial?
Which free tool is best for engineers learning solar design?
Nirav Dhanani CEO, Qbits Energy
Co-founder & CEO driving Qbits Energy's product strategy and growth across India.