Best Solar Design Software in 2026: 10 Top Tools for Installers (Free + Paid)

Every solar installer needs design software to estimate generation, lay out panels on a shade-free roof, size the system, and produce engineering drawings and proposals. But the 2026 market is crowded, and the right tool depends on whether you do residential rooftops, commercial and industrial projects, or utility-scale plants - and on your budget.

This guide ranks the 10 best solar design software tools in 2026, with what each is best for, real review sentiment from r/solar, G2 and Capterra, and honest pros and cons. Start with the comparison table, then jump to any tool. At the end we cover the part no design tool handles: running the sales pipeline and the installation project.

What solar design software actually does

A good PV design tool estimates the solar resource at a site, calculates the shade-free area, designs a layout that meets the target output, projects the energy yield, and generates the engineering drawings and a customer proposal. Some tools focus on speed and sales proposals; others on engineering accuracy and bankable simulation. Many installers use one of each - a sales-design tool plus a simulator.

The 10 best solar design software tools in 2026

1. Aurora Solar

Best for: Residential + C&I design and sales proposals

Cloud SaaSSubscription (quote-based)PaidReviews: G2 ~4.7 - Capterra ~4.4

What reviewers say: On r/solar it's repeatedly called 'the best by far' and the easiest for residential - but the per-user price is the constant gripe ('I like Aurora best, but that $170...'). Capterra carries both glowing reviews and a few calling it 'an expensive ripoff'.

PROS

• Easiest, most polished for residential
• Highly accurate design + NREL-grade shading
• Proposals that help close deals
• Submodule-level production modelling

CONS

• Expensive per-user pricing
• Overkill for occasional / very small installers
• Some advanced features cost extra

2. OpenSolar

Best for: Free design, proposals and project management

CloudFree (no per-seat cost)Free

What reviewers say: The default free recommendation on r/solar - installers run it standalone or pair it with a paid simulator. The trade-off versus Aurora is polish and support, not core capability.

PROS

• Completely free for installers
• Full design + proposal + light CRM
• No per-seat cost as you grow
• Large installer community + the #1 free pick in India

CONS

• Monetises via hardware/financing marketplace
• Less hand-holding/support than paid tools
• UI less refined than Aurora

3. HelioScope (by Aurora)

Best for: Commercial / C&I engineering design

Cloud (browser, no install)Subscription (reportedly ~$99-300/user/mo)Paid

What reviewers say: The default r/solar pick for commercial work ('good for commercial'), and liked because 'there's no need to install anything, just a browser'. Now owned by Aurora.

PROS

• Browser-based, nothing to install
• Strong C&I / commercial modelling
• Detailed single-line diagrams
• Accurate component-level simulation

CONS

• Less suited to slick residential proposals
• Subscription cost
• Part of Aurora's ecosystem now

4. PVsyst

Best for: Bankable energy-yield simulation

Windows desktopPaid license (reportedly ~EUR 500/yr; free trial)Free trial

What reviewers say: Universally called 'the most reputable' simulator on r/solar - and just as universally called 'expensive' and 'hard to use'. It's the tool lenders trust for third-party engineering review, not a sales tool.

PROS

• Industry-standard bankable simulation
• Deepest loss analysis + most accurate yield
• Trusted by financiers and lenders
• The reference for engineering review

CONS

• Steep learning curve
• Windows-only desktop install
• Not a design/proposal tool
• Dated interface

5. Arka 360 (The Solar Labs)

Best for: India-built 3D design + proposals

CloudSubscription (free trial)Free trial

What reviewers say: Popular with Indian installers and EPCs who want fast 3D design and branded proposals with a local-market fit - an India-origin alternative to Aurora at a lower price point.

PROS

• Fast 3D design + shading analysis
• Branded, professional proposals
• India-market fit and pricing
• Actively growing feature set

CONS

• Smaller ecosystem than Aurora
• Less independent (English) review data
• Best for residential/C&I, not utility-scale

6. Solargraf (by Enphase)

Best for: Fast residential proposals

CloudSubscriptionFree trialReviews: Mixed: ~3.2-3.7 / 5 (Capterra 3.2)

What reviewers say: The most polarising tool here. Some reviewers find it 'very user friendly' with 'extremely high accuracy'; others on Capterra call it 'incredibly frustrating... data is often wrong... crashed often'. The category-low average reflects that split.

PROS

• Fast, permit-ready residential proposals
• Backed by Enphase
• User-friendly for some teams

CONS

• Mixed reliability and accuracy reports
• Limited customization
• Crashes/bugs reported
• Below-average ratings

7. Pylon

Best for: Fast-growing installers wanting low fixed fees

CloudFreemium / usage-basedFree

What reviewers say: Built around zero fixed fees, which resonates with smaller and emerging-market installers (including India) who can't justify Aurora's per-seat cost.

PROS

• Low / zero fixed fees
• Design + proposals + e-signature
• Good for small, growing teams
• Popular in India and emerging markets

CONS

• Less feature depth than Aurora
• Less proven for complex C&I
• Limited independent reviews

8. RatedPower

Best for: Utility-scale plant engineering

CloudEnterprise (quote)PaidReviews: G2 4.4 / 5 (250+ reviews)

What reviewers say: Well-rated by utility-scale developers and EPCs for automating plant layout, BOM and yield - but it's overkill for rooftop installers.

PROS

• Automates utility-scale layout + BOM
• Strong energy-yield optimization
• Solid support (per G2)
• Built for developers and EPCs

CONS

• Enterprise pricing
• Overkill for rooftop/residential
• Steeper for small teams

9. PVcase

Best for: Utility-scale ground-mount in AutoCAD

AutoCAD plug-in / CloudEnterprisePaid

What reviewers say: Favoured by engineering teams already in AutoCAD for terrain-aware ground-mount design; pairs with its Prospect tool for site prospecting.

PROS

• Terrain-aware ground-mount design
• Works inside AutoCAD
• Site prospecting via Prospect
• Strong for large projects

CONS

• Enterprise-only
• Not for rooftop/residential
• Requires AutoCAD knowledge

10. SolarEdge Designer

Best for: Free design when using SolarEdge hardware

CloudFreeFree

What reviewers say: Grouped with the free, browser-based options on r/solar - a no-cost, capable choice if you're already specifying SolarEdge inverters.

PROS

• Completely free
• Browser-based
• Capable residential/C&I design
• No cost if using SolarEdge

CONS

• Tied to the SolarEdge ecosystem
• Less neutral / flexible
• Basic next to Aurora

How to choose the right solar design software

Residential installers selling on speed and a slick homeowner proposal are best served by OpenSolar (free), Solargraf, Pylon or Aurora. Commercial and C&I work calls for HelioScope or Aurora, with PVsyst for bankable yield. Utility-scale developers and EPCs need RatedPower or PVcase. If budget is the constraint, start with OpenSolar or SolarEdge Designer - both free and capable. In India, OpenSolar, Arka 360, Solar Ladder and Pylon are the common picks, with larger EPCs adding Aurora or HelioScope. A pattern from r/solar: teams that need engineering depth pay for two tools (a sales-design tool plus PVsyst), so factor total cost, not just one subscription.

Design software ends where running the business begins

Here is the gap every growing installer hits: your design tool produces a beautiful design and proposal, but it does not chase the lead, send the follow-ups, track the BOQ and payment milestones, schedule the installation crew, or raise the GST invoice on commissioning. That is the job of a solar CRM, not a design tool.

Most installers that scale pair the two: design in Aurora or OpenSolar, then run the deal and the project in a CRM. Fuzen's Solar CRM template handles leads and lead scoring, quotations and BOQ, PM Surya Ghar subsidy tracking, installation scheduling, GST invoicing and WhatsApp follow-ups - and you bring the engineering design from whichever tool above you prefer. See how to connect your solar CRM with your design tools, the top solar CRM integrations, or compare options in the best solar CRM in 2026 and the best solar project management software.

Frequently asked questions about solar design software

What is the best solar design software in 2026?

Aurora Solar is the most powerful all-rounder for design and sales proposals, while OpenSolar is the best free option. For bankable energy simulation use PVsyst, and for the Indian market Arka 360 and Solar Ladder are strong, locally built choices. Most reviewers on r/solar pair a sales-design tool (Aurora/OpenSolar) with a simulator (PVsyst) for engineering-heavy work.

Is there free solar design software?

Yes. OpenSolar is fully free for installers, SolarEdge Designer is free if you use SolarEdge hardware, and PV*SOL online offers free PV calculations. OpenSolar is the most complete free option for design, proposals and project management.

Why is Aurora Solar so expensive?

Aurora prices per user on a quote basis, and installers on r/solar and G2 consistently cite cost as the main downside (around the price of a paid SaaS seat per month). You pay for accuracy, polished proposals and ease of use; very small or occasional installers often start on OpenSolar instead and move up later.

Which solar design software is best in India?

OpenSolar (free), Arka 360, Solar Ladder and Pylon are popular with Indian installers, while larger EPCs also use Aurora and HelioScope. SolarEdge Designer is a free option for SolarEdge installs.

Do I need a CRM as well as solar design software?

Yes. Design software draws the system and proposal, but it does not chase leads, track BOQ and payments, schedule the installation, or raise GST invoices. A solar CRM such as Fuzen runs the sales and project side, and you bring the engineering design from whichever design tool you prefer.