What is the best solar design software?

It depends on how you sell. Teams that close with integrated financing are best served by Aurora Solar, budget-first teams by the free OpenSolar, installers who quote on site from a phone or tablet by Reonic, C&I engineers who need a lender-ready yield by HelioScope, and teams that want design, single-line diagrams, proposals and the CRM in one product, across PV, batteries and heat pumps, by solarVis. The quick picks at the top of this page have the full list.

Is there free solar design software?

Yes. OpenSolar's core platform is free for design, proposals, CRM, e-signature and payments, funded by hardware and finance partners; since April 2026 it charges for API Access, Connectors and higher-resolution imagery. Several paid tools offer trials instead: HelioScope, Solar Monkey (14 days) and solarVis (7 days).

What is the difference between solar design software and simulation software?

Design software takes a roof to a proposal quickly, with a yield estimate good enough to sell on. Dedicated simulation software produces the detailed, probabilistic yield a bank or investor signs off. Some tools sit between the two: HelioScope benchmarks its model against the industry reference, and Solargraf's estimates were validated by NREL.

Which solar design software handles commercial and industrial projects?

HelioScope is built for commercial engineering, with trackers and systems up to 30 MW DC on Enterprise. SolarVis designs commercial and industrial sites in the same product as homes, up to 50 MW in a single design, with several buildings per project and flat-roof layouts. Solargraf supports flat-roof and ground-mount designs, and Aurora Solar sells HelioScope for commercial work.

Which solar design software produces single-line diagrams?

Most of the tools in this guide. Aurora Solar and solarVis export them, Reonic draws them for residential projects, OpenSolar generates them from regional templates in nine countries, HelioScope exports them to CAD with combiners, and Solargraf produces single- and three-line diagrams; Solar Monkey does not list them. In solarVis the diagram is generated from the stringing design, checked electrically while you draw, and exported as a PDF on your own title block or as a DXF.

Does solar design software use LiDAR?

Most of it does, where the data exists. Aurora Solar and OpenSolar use LiDAR-assisted modelling, HelioScope adds it on Pro, Solar Monkey builds on a 3D elevation model, and solarVis runs Fit to LiDAR after AI Roof Detection. All of them depend on aerial data coverage for the address. Reonic models roofs from satellite, orthophoto or drone imagery and uses LiDAR indoors, scanning rooms on an iPhone or iPad Pro for the heat load.

What software do UK MCS installers use for performance estimates?

Among the tools in this guide, Aurora Solar (since its UK launch in September 2026), OpenSolar and solarVis list MCS documents. SolarVis produces the MCS Performance Estimate and an MIS 3002 shade report for Great Britain, Northern Ireland and the Isle of Man.

Can one tool cover design, proposal and CRM?

Yes. OpenSolar, Reonic and solarVis have a CRM built in. Aurora Solar, Solargraf and Solar Monkey integrate with the CRM you already run instead.

How often is this comparison updated?

Every vendor's facts are re-checked at least every 90 days, and the date at the top of the page is the last full check. If a vendor ships something that changes a row, we update the row and the date.

Buyer's guide

Solar design software in 2026: how to choose, and which tool fits your business

Solar design software takes a roof from satellite image to a priced proposal: it captures the roof, lays out panels and strings, simulates the yield and builds the document the customer signs. Which tool fits depends on how you sell. Teams that close with integrated financing lean to Aurora Solar, budget-first teams to the free OpenSolar, installers who quote on site from a tablet to Reonic, C&I engineers who need a lender-ready yield to HelioScope, and teams that want design, engineering, proposal and CRM in one product, across PV, batteries and heat pumps, to solarVis.

We make solarVis. It is one of the seven tools below, compared on the same criteria as the rest, and the tool profiles say where each of the others is the better choice.

Book a DemoLast verified September 11, 2026

Quick picks by business type

If you are	Look first at	Because
A residential team that closes with financing inside the proposal	Aurora Solar	Design automation, bankable shade reports, cash, loan, lease and PPA options, permit-ready documentation (US)
A small residential team where budget decides	OpenSolar	The core platform is free, end to end, funded by hardware and finance partners
An installer that quotes and closes on site from a phone or tablet	Reonic	iOS and Android apps, heat pumps sized to a DIN EN 12831 heat load, e-signature on quotes, grid registration as a service (DE)
A C&I engineering team that needs a lender-accepted yield	HelioScope	Within 1% of PVsyst by its own benchmark, recognised as bankable by Sunstone Credit, trackers on Enterprise
An installer built around Enphase hardware that wants permit packages generated	Solargraf	Enphase's own design, proposal and permitting platform, with single- and three-line diagrams and automated permit packages (US)
A residential installer that wants fast quotes inside the CRM it already runs	Solar Monkey	String checks against manufacturer specs, battery scenarios, and integrations with Pipedrive, Salesforce, Zoho and Odoo
A team that wants design, engineering, proposal and CRM in one product, selling PV, batteries and heat pumps from homes to 50 MW sites	solarVis	PV, battery and heat pump in one feasibility, automatic stringing with a single-line diagram, 26-page proposals with view tracking, a stage-gated CRM and tariff rules for 45+ countries

What solar design software does

Every tool in this guide does the same four jobs, in the same order: capture the roof, lay out the system, estimate what it will produce and turn that into a proposal. Where they differ is how far past those four jobs they go, and for whom. Four kinds of product share the category:

Residential sales design tools optimise for speed to a proposal a homeowner signs: automatic roof capture, a clean customer document, financing where the market expects it. Aurora Solar, Solargraf and Solar Monkey sit here.
Commercial engineering tools optimise for accuracy an engineer or a lender will sign off: detailed electrical design, single-line diagrams, probabilistic yield. HelioScope is the reference.
All-in-one sales platforms carry the design through to the pipeline, so the design, the proposal and the CRM share one record. Reonic, OpenSolar and solarVis are built this way.
Free, partner-funded platforms trade a subscription for a business model paid for by hardware and finance partners. OpenSolar is the example.

The terms overlap in search. Solar design software and PV design software usually mean the design step; solar proposal software the document that closes; and solar sales software the whole path from lead to signature.

How to evaluate it: seven questions

Ask them in this order, because it is the order in which an installer's week runs into the tool. Each maps to one row group of the comparison matrix below.

1. Access: can you try it on your own project?

A demo shows the vendor's best project; a trial shows yours. Ask whether you can design a real roof before a sales call, what the trial includes, and whether the proposals it produces during the trial are usable.

2. Market fit: are your rules built in?

Payback depends on the tariff, the export rule and the paperwork. Ask whether your country's time-of-use schedules, net metering or net billing, and compliance documents are already in the tool, or typed in per project. In the UK that means MCS documents and Smart Export Guarantee rates; in South Africa, Eskom or municipal tariffs and SSEG rules.

3. Site and roof: how is the roof captured, and what happens when data runs out?

Ask how the roof is modelled (AI detection, LiDAR, drone photogrammetry, a DXF from a surveyor), what the tool does where aerial data does not cover the address, and whether it handles stepped roofs, extensions at a different height and several buildings on one site.

4. Layout and engineering: how much is automatic, and how big can it go?

Ask whether panels and strings are placed automatically and checked against the inverter, whether it produces single-line diagrams, and how large a system fits in one design. Capacity ceilings differ by an order of magnitude between tools.

5. Yield and feasibility: would a lender accept the number?

Ask how shading is simulated (per panel, per cell, hourly), whether batteries and heat pumps are modelled or only listed, what financial outputs you get, and whether any lender or laboratory has validated the yield.

6. Proposal and close: what does the customer see?

Ask how configurable the proposal is, whether you see when the customer opens it, and whether financing and signature live inside it or somewhere else.

7. Pipeline and operations: what happens after the proposal?

Ask whether there is a CRM or an integration to yours, whether the tool captures leads from your website, and whether it works on a phone or tablet on site.

The comparison matrix

"Not listed" means the vendor's public pages say nothing about a capability, not that the capability is absent.

Capability	solarVis	Aurora Solar	OpenSolar	Reonic	HelioScope	Solargraf	Solar Monkey
Access
Try before a sales call	7-day trial	Demos only	Free core platform	Book a demo	Free trial	Not listed	14-day trial
Market fit
Markets served	Tariffs and regulations, 45+ countries	US-first; UK, DE, ES, FR	Users in 185+ countries	13 markets, Germany first	100+ countries (2021)	US, CA, BR, DE, AT, NL, JP	NL, BE, DE, ES, UK
UK MCS documents	Yes, MIS 3002 reports	Yes, since September 2026	Yes	For heat pumps (MCS-ready)	Not listed	Not listed	Not listed
Site and roof modelling
Roof capture	AI roof detection, Fit to LiDAR	AI roof detection, LiDAR	Ada auto-design, LiDAR	Satellite, orthophoto and drone imagery	LiDAR-assisted (Pro)	AI roofline, obstruction and tree detection	Aerial photos, 3D elevation model
DXF or CAD	Import and export	Export	Export	Not listed	Export	Not listed	Not listed
Layout and engineering
Automatic stringing	Full Auto and Guided	Yes	Yes	Yes	Yes, from site temperatures	Electrical design tool	String plan with spec checks
Single-line diagrams	Single-line, from the stringing; PDF and DXF	Yes	Nine countries, incl. UK, DE, IT, ES, FR	Residential; JPEG, PDF	Yes, to CAD	Single- and three-line	Not listed
Largest project per design	Up to 50 MW	Not listed	Not listed	Not listed	30 MW DC (Enterprise)	Not listed	Not listed
C&I projects	Same product as homes	Via HelioScope	Yes	Not listed	Core focus	Flat roof and ground mount	Not listed
Yield and feasibility
Yield validation	No lender designation	Bankable shade reports	Not listed	Not listed	Bankable per Sunstone Credit	NREL-validated	Not listed
Battery modelling	Self-consumption, autonomy, arbitrage	Arbitrage (Premium)	Savings and peak-shaving schemes	Yes, dynamic prices	Storage design	Solar plus battery	Battery scenarios
Heat pumps	Sized, in one feasibility with PV and battery	Modelled for EU projects (limited release), not sized	Running costs (beta), not sized	Sized to a DIN EN 12831 heat load	Not listed	Not listed	In proposals
Proposal and close
Integrated financing	No, payment plan only	Cash, loan, lease, PPA	Integrated finance, CashFlow	Not listed	Not listed	TPO integrations (US)	Not listed
Permit packages	No	AHJ database (US)	SolarAPP+ (US)	Grid registration service (DE)	Not listed	Automated AHJ permits (US)	Not listed
Pipeline and operations
CRM	Built in, customizable pipelines	Integrates	Built in	Built in	Not listed	Integrates	Integrates (Pipedrive, Salesforce, Zoho, Odoo)
Website lead capture	Lead Generator, AI Sales Agent chat (add-ons)	Embedded Leads (US)	AI Lead Gen form (beta)	Energy House configurator; AI phone and WhatsApp intake	Not listed	Not listed	Not listed
Mobile	Browser-based	Not listed	Mobile app	iOS and Android	Not listed	Not listed	Browser-based

Last verified 11 September 2026; the Aurora Solar, OpenSolar and Reonic columns re-checked on 29 September 2026. Every competitor cell comes from that vendor's own website, product pages, help centre or press releases. Re-checked every 90 days.

The tools, one by one

Aurora Solar

The US market leader, founded in San Francisco in 2013, used by more than 7,000 organizations with over 20 million projects designed. Its AI builds a 3D roof model in seconds, LiDAR sharpens it and bankable shade reports back it up; proposals carry US financing (cash, loan, lease, PPA) with e-signature, and a 25,000+ AHJ database feeds permit documents. Commercial engineering is sold separately, as HelioScope. Since 2025 it has built out in Europe, with regional sites for Germany, Spain and France and heat pump modelling for eligible installers in Germany, and in September 2026 it launched in the UK.

Best for: residential teams that close with financing inside the proposal, mainly in the US.
Watch for: demos only, no free trial; outside the US, tariffs are set up as custom rates.
UK and South Africa: launched in the UK in September 2026 with MCS-compliant proposals; no South African presence is listed.
Full comparison: Aurora Solar vs solarVis

OpenSolar

A free, end-to-end platform founded in Sydney in 2017, with 28,000+ active professionals in 185+ countries. Ada auto-designs systems, SolarTouch designs on mobile, and proposals carry integrated finance, e-signature and CashFlow payments. Since 16 April 2026 API Access, third-party Connectors and higher-resolution imagery are charged; hardware and finance partners fund the rest.

Best for: residential teams where budget decides.
Watch for: heat pump running costs are modelled, but the pump is sized in another tool; no chatbot on your own website.
UK and South Africa: MCS support and UK single-line diagrams; strongest UK fit of the free options.
Full comparison: OpenSolar vs solarVis

Reonic

A German all-in-one platform with offices in Berlin, Augsburg and São Paulo, reporting over 3,000 customers in 13 markets. It designs from satellite, orthophoto or drone imagery, strings automatically, draws residential single-line diagrams, sizes heat pumps against a DIN EN 12831 heat load, simulates EV demand and dynamic electricity prices, and ships iOS and Android apps with LiDAR room scanning. Its AI answers homeowners by phone and WhatsApp and reaches into the back office, and in Germany it sells grid registration and KfW applications as services.

Best for: installers who quote on site from a phone or tablet and plan heat pumps in depth.
Watch for: the way in is a booked demo; its deepest localisation is German.
UK and South Africa: active in the UK, with a heat-load calculator and MCS-ready heating workflows; an English page for South Africa, with no local features listed.
Full comparison: Reonic vs solarVis

HelioScope

Aurora's commercial design and simulation platform, built by Folsom Labs and acquired in 2021. It states its production model is within 1% of PVsyst, validated by DNV, NREL and the CEC, and in October 2025 Sunstone Credit recognised it as bankable. Tiers take systems up to 1.25, 5 and 30 MW DC; Enterprise adds single-axis trackers, PVsyst export and an API. String lengths are set from site temperatures, and single-line diagrams export to CAD.

Best for: C&I engineering teams that deliver a lender file and drawings.
Watch for: its pages list no CRM or website lead capture; IRR and LCOE start on Pro.
UK and South Africa: rates are set up in its Utility Rate Editor rather than pre-configured.
Full comparison: HelioScope vs solarVis

Solargraf

Enphase's design, proposal and permitting platform. It detects rooflines, obstructions and trees automatically, produces permit-ready single- and three-line diagrams, supports flat-roof and ground-mount commercial designs, and generates AHJ-ready permit packages in the US. In September 2025 NREL validated its production estimates against measured PV data, with accuracy comparable to NREL's own System Advisor Model. It reports 3 million+ proposals, 1 million+ permits and 1,000+ customers, in 16 languages.

Best for: installers built around Enphase hardware who want permits generated.
Watch for: financing integrations are US third-party-ownership providers; no trial is listed.
UK and South Africa: neither is among its listed markets (US, Canada, Brazil, Germany, Austria, the Netherlands, Japan).

Solar Monkey

A Dutch platform trusted, by its own count, by more than 500 installation companies in the Netherlands, Belgium, Germany, Spain and the UK (since August 2023). It models roofs from aerial photos and a 3D elevation model, detects shade per panel, checks string plans against manufacturer specifications, and compares battery scenarios. Proposals are templated with digital signing, and it integrates with Pipedrive, Salesforce, Zoho and Odoo.

Best for: residential installers who want fast quotes inside an existing CRM.
Watch for: single-line diagrams and commercial projects are not listed.
UK and South Africa: active in the UK, with no MCS documents listed; no South African presence is listed.

solarVis

An all-in-one sales and design platform with an engineering-grade engine. AI Roof Detection returns the roof outline and Fit to LiDAR sets height and slope where high-resolution data covers the address; the 3D design models stepped roofs, with adjoining sections at their own height and roof type, and several buildings in one project, up to 50 MW in a single design. AI panel placement fills each roof to a target, Automatic Stringing checks every MPPT, and the single-line diagram is generated from those strings, checked electrically as you draw and exported as a PDF on your own title block or as a DXF. Feasibility runs PV, battery and heat pump together on a cell-level, 8760-hour engine with tariff rules for 45+ countries; 26 configurable proposal pages go out by email, SMS, link or WhatsApp with view tracking; and the CRM tracks every project to installation.

Best for: installers and EPCs that want design, engineering, proposal and pipeline in one product, selling PV, batteries and heat pumps from homes to large commercial sites.
Watch for: no integrated financing, no permit packages, no native mobile app, no lender designation, no trackers; diagrams are single-line only.
UK and South Africa: MCS documents and Smart Export Guarantee modelling in the UK; around 180 Eskom and municipal tariffs and battery autonomy in South Africa.
More: Solar Proposal Software and Solar 3D Design & Simulation

Commercial and industrial projects: what changes

A commercial roof is not a house with more panels. Four things change, and they separate the tools faster than any feature list.

The site, not the roof. A logistics park has several buildings, stepped roofs and plant rooms. Ask whether all of it fits in one project, and whether a lower extension can sit at its own height and roof type.
Flat-roof layout. South-facing tilted rows or paired east-west tables, with service corridors and wind edge zones kept clear, decide how much capacity the roof really holds.
Capacity per design. Few vendors publish a ceiling. HelioScope's tiers stop at 1.25, 5 and 30 MW DC; solarVis takes projects up to 50 MW in a single design. For the others, ask.
Who signs off the yield. A commercial buyer's bank may want a validated production estimate and single-line diagrams. HelioScope holds a lender designation and Solargraf an NREL validation; if your lender names a tool, produce the lender file there.

Tariffs matter more here than on a home: demand charges and time-of-use schedules can swing a C&I payback by years, so check that they are modelled, not averaged. See also: commercial solar, solar trackers, HelioScope vs solarVis.

Selling in the UK and South Africa

United Kingdom. A domestic sale needs an MCS performance estimate and MCS shade assessment, the customer's Smart Export Guarantee rate (set by each supplier, not nationally), the right VAT treatment and, before connection, a DNO notification or application under G98 or G99. Ask which of those the tool produces and which stay with you. Of the seven tools here, Aurora Solar, OpenSolar and solarVis list MCS documents; solarVis models the Smart Export Guarantee as net billing, with default export rates you edit per project to match the customer's supplier. None lists DNO applications.

South Africa. Tariffs depend on the address: some customers are billed by Eskom directly, others by their municipality, often on time-of-use. Grid-tied systems need SSEG registration under municipal frameworks that follow NERSA guidance, and years of load shedding have made backup autonomy the first question a customer asks. Ask whether the tool knows your municipality's tariff, models a battery for autonomy as well as savings, and designs off-grid or zero-injection systems. SolarVis preloads around 180 Eskom and municipal tariffs with seasonal time-of-use and lets you build a custom tariff where a municipality is missing. None of the seven lists load-shedding schedule simulation, and none files SSEG registrations.

How we compared

We make solarVis, so this page is written to be checked. Every tool is compared on the same seven questions and the same matrix rows. Competitor facts come only from each vendor's own website, product pages, help centre and press releases, never from review sites run by a competitor; solarVis facts come from the product itself. Where a vendor's pages say nothing about a capability, the matrix says "Not listed" rather than "No". Each vendor is re-checked at least every 90 days, and prices are not compared on this page.