Most OpenSolar review pages fall into one of two traps. They either treat “free” as a marketing lie and go hunting for a hidden invoice, or they treat it as charity and skip the question of who is actually paying. Both are wrong. OpenSolar is free, it has been free since it launched, and the money comes from somewhere specific and knowable: manufacturers, distributors, finance companies, permitting providers and training partners pay to reach the installer network on the platform. That is the entire story, and once you understand it you can judge the software properly. Heaven Green Energy has watched installer partners run their whole residential business on it, and on our five-axis bench it scores 37 out of 50, which is a serious score for a product with a zero-rupee, zero-dollar price tag. For a large group of readers it is simply the right answer, and this page says so.
Direct answer. OpenSolar is a genuinely free solar design, proposal and CRM platform used by more than 28,000 solar professionals in 185 countries, funded by hardware, finance and distribution partners rather than by installer subscriptions. It scores 37 out of 50 on our review bench. Use it if you are a solo installer or a residential team under four people. Its limit is engineering depth, not price.
This review covers what OpenSolar is, how the funding model works and what it means for you as a user, the five-axis score, the April 2026 API pricing change that changed the picture at the edges, who should use it, who should not, and an honest comparison against SurgePV where SurgePV loses the price argument completely. If you have already decided to move, our OpenSolar alternatives guide ranks the options, and our OpenSolar pricing analysis covers the total-cost question in more depth than this page does.
What OpenSolar Is
OpenSolar is a cloud platform covering solar design, proposal generation, e-signature, CRM and, in newer releases, payments. It was founded in Australia by Andrew Birch, previously a co-founder of Sungevity, on a thesis that installer soft costs were the binding constraint on residential solar growth and that charging installers for design software made that worse. The product launched free and has stayed free.
Scale matters when judging a free tool, because a free tool that nobody uses is an abandoned tool. OpenSolar reports more than 28,000 solar professionals across 185 countries, over 6 million systems designed and roughly $10 billion in solar sales transacted through the platform. It raised a $20 million equity round in 2025 while keeping the product free, as reported by Mercom Capital Group, which is the most recent funding datapoint we could source for the partner-funded model.
Functionally, a designer types an address, gets satellite imagery, traces the roof, places modules on pitched planes, applies a shading model, sizes the system against a component database, and produces a customer-facing proposal with financing options and an e-signature flow. There is a CRM behind it with pipeline stages, task management and follow-up. In the OS 3.0 generation, OpenSolar added Ada, a voice-driven auto-design assistant, and CashFlow, a payments layer that lets installers take deposits and progress payments in-platform.
That is a complete residential business in one login, at no licence cost. It is a genuinely impressive product and reviews that lead with “but what’s the catch” before describing what it does are burying the story.
Bring one of your own sites to a free SurgePV demo. We will build the 3D roof from a satellite address, run the 8,760-hour shading simulation, and hand you the SLD, BOQ and branded proposal on the call.
Book a free SurgePV demo → Compare pricingHow “Free” Actually Works, and What It Means For You
OpenSolar states the model openly. Its own explanation of why the platform is free names the paying parties: product manufacturers, finance companies, distributors, solar permitting companies and education providers. They pay for presence in front of the installer network. The installer pays nothing.
This is not unusual and it is not sinister. It is the same shape as a marketplace: the side with margin subsidises the side with volume. But it has three consequences a buyer should think about before standardising a business on it.
Our read is that the product optimises for what the payers value. Features that route procurement, financing and permitting through partner channels look the most built out to us. Features that do not touch a partner, deep simulation reporting for instance, are not where that incentive would point. That is not a criticism of anyone’s integrity, it is an inference from the funding model, and in our view it explains the shape of the product.
Your bargaining position is asymmetric. You are not paying, so you are not the party the commercial terms are negotiated with. If the terms change, there is no subscription contract on your side of the table and no renewal at stake. Most of the time this is fine. It stops being fine when the terms change at a boundary you depend on.
Which is exactly what happened in 2026. From 16 April 2026, OpenSolar began charging for API Access and Connectors. Its own announcement puts it plainly: if your data is created and retained inside OpenSolar, the core app stays free. Connecting OpenSolar to an external CRM, accounting system or reporting stack now costs money. Existing API users had to enable API Access by 17 March 2026, with a 30-day free trial, and set up an OpenSolar Wallet for billing.
📘 What this actually means
Free inside the walls, priced at the door. If your whole business runs in OpenSolar, nothing changed. If your accounting, CRM or BI sits outside it, the free platform now has a line item. OpenSolar has not published the rates, so budget it as an unknown.
We are not going to pretend that is a scandal. It is a reasonable commercial move and the core promise held. But it is the single most useful thing to know before you commit, and most review pages have not caught up to it.
The 5-Axis Review Bench
Every review on this site uses the same five axes, scored out of 10 against a defined question, so scores are comparable between tools. We call it the Heaven Green 5-Axis Review Bench.
- Design and simulation depth. Hour-by-hour irradiance at module or string level, real obstruction geometry, and losses separated into shading, soiling, mismatch and thermal so an engineer can defend the number.
- Compliance and documentation output. Single line diagram, conductor and overcurrent sizing, placards, bill of quantities: a package a plan checker or contractor can build from.
- Proposal and sales workflow. Branded, financeable, signable customer document from the same file, with a pipeline behind it.
- Price against value. Cost per finished project across a realistic team, including what is gated or metered.
- Support and onboarding. Time from signup to a designer shipping unsupervised work.
| Axis | Score | Reasoning |
|---|---|---|
| Design and simulation depth | 6 / 10 | Competent shading and yield for residential. No module-level 8,760-hour loss tree you would hand a lender |
| Compliance and documentation output | 5 / 10 | Weak on single line diagrams and BOQ export. Permitting is routed to partners rather than generated |
| Proposal and sales workflow | 9 / 10 | Excellent. Branded proposals, financing, e-signature, CRM and now payments, all native |
| Price against value | 10 / 10 | Free, unlimited users, unlimited projects. Nothing else on our bench scores here |
| Support and onboarding | 7 / 10 | Fast to learn, large community, good documentation. Support is community-weighted, as free products are |
| Total | 37 / 50 | The highest score any free platform has recorded on this bench |
Verdict. OpenSolar is a sales platform with a good-enough design tool inside it, given away for free, and that combination is correct for more installers than the industry likes to admit. It is not an engineering tool, and buying it expecting one is the only real way to be disappointed by it.
What OpenSolar Does Best
The price, and it is not close. Zero licence cost, unlimited users, unlimited projects. On list prices, a three-person residential shop avoids roughly $4,500 to $8,000 a year in licence cost against a paid alternative, which for a business doing 15 jobs a month can be a meaningful share of net margin. Any review that treats this as a footnote is not reviewing the product installers actually experience.
Proposal and close workflow. This is where the partner-funded incentive works in your favour. Because OpenSolar’s revenue depends on installers closing deals through the platform, the proposal, financing and e-signature path is genuinely well built. Interactive proposals, financing options presented cleanly, signature capture, and the CRM stages behind them. Plenty of paid tools are worse at this.
Global coverage. 185 countries with local component databases and tariff structures in many of them. Distributed solar is growing fastest outside the traditional US and European markets, per IEA solar PV tracking, and OpenSolar’s footprint follows that growth rather than lagging it. If you install in a market that Aurora and its US peers treat as an afterthought, OpenSolar may simply be the only platform with your utility rates in it.
Speed to first proposal. A new user can produce a customer-ready residential proposal on day one. Onboarding cost is close to zero, which matters enormously for a small team where the owner is also the designer and the closer.
No procurement conversation. No purchase order, no seat forecast, no annual renewal negotiation, no finance approval. For a one-person business that is worth real time.
Where OpenSolar Falls Short
Simulation depth stops short of what lenders typically ask for. OpenSolar’s shading and yield model is fine for a residential rooftop where the customer wants a good estimate. In the version we tested in August 2026 we did not find a module-level 8,760-hour simulation with a loss tree separating shading from soiling, mismatch and thermal. When a lender, a utility programme or an engineering reviewer asks you to defend an annual yield on a 400 kW commercial roof, you will be exporting to something else. Our solar shading analysis software guide covers what that standard actually requires.
Documentation output is the weakest axis. Single line diagrams, conductor sizing tables, overcurrent protection schedules and a clean bill of quantities are not OpenSolar’s strength. If your workflow is design then permit then build, you will be redrawing in AutoCAD or outsourcing the package. Teams in that position usually pair it with an engineering service such as Heaven Designs permit design rather than a second software licence.
Commercial and industrial work outgrows it fast. The tool is residential-shaped. Ground mounts, carports, multi-MW rooftops, tracker layouts and terrain are not what it is for. See commercial solar design software for tools that are.
The API boundary now has a price. Covered above, and worth repeating because it is the practical version of the platform-risk argument. If your growth plan involves connecting OpenSolar to anything else, that plan now has an unpublished cost in it.
Support is community-weighted. Documentation and forums are good. A guaranteed response time when a proposal will not render 20 minutes before a customer meeting is a different thing, and free products do not generally offer it.
Comparing tools rather than picking one? Our solar design software pillar covers the whole category, and the best solar design software ranking puts them in order with prices. Talk to our engineering team →
Who Should Buy OpenSolar
We will state this without qualification, because it is true and hedging it would be dishonest.
If you are a solo installer or a residential team of two to four people, OpenSolar is the correct choice, and you should not pay for a design tool. Your projects are pitched residential roofs between 3 and 15 kW. Your customer wants a clear proposal with a credible production number and a financing option, not a P90 exceedance report. Your permits are handled by your electrical contractor or a permitting service. Your bottleneck is closing deals, not defending simulations. OpenSolar does the whole job, it does the closing part better than several paid tools, and spending $1,600 to $2,600 a year per seat to get engineering depth you will never invoice for is a bad allocation of capital in a business where cash is the constraint.
Two adjacent readers belong here too. Installers in markets the US-built platforms ignore, where OpenSolar’s tariff and component libraries are the only ones that match reality. And new entrants and training organisations, where unlimited free seats mean you can put the whole cohort on real software.
Who Should Not
Anyone producing lender-facing or utility-facing yield reports. You need a module-level annual simulation with a readable loss tree. That is a different product class. Read our PVsyst review and HelioScope review for the two tools that own this.
Teams whose main deliverable is a permit package. Documentation output is the weak axis, and redrawing costs more designer hours than a licence costs money once you cross roughly ten permit packages a month.
C&I and utility-scale developers. Ground mount, terrain, trackers and multi-MW layouts are outside the design intent. Look at utility-scale solar design software instead.
Teams that need OpenSolar data in an external system. After April 2026 that is a paid, unpublished-rate capability. Price it before you architect around it.
Anyone who needs a support SLA. If a stalled proposal on a Friday afternoon costs you a deal, buy a product with a contract behind the support desk.
OpenSolar vs SurgePV
Disclosure, stated plainly: SurgePV is a sister product of Heaven Green Energy and we run it on our own EPC work. We benefit if you choose it. That is exactly why this section will not pretend SurgePV beats a free product on price. It does not, and it cannot.
| Axis | OpenSolar | SurgePV | Honest read |
|---|---|---|---|
| Simulation depth | 6. Residential-grade shading and yield | 9. 8,760-hour module-level simulation on every paid plan | SurgePV wins, and this is the entire argument |
| Compliance output | 5. Weak SLD and BOQ, permitting routed to partners | 7. SLD, BOQ, DXF and DWG export bundled, multi-country code libraries | SurgePV wins |
| Proposal workflow | 9. Excellent, plus native CRM and payments | 9. White-label proposals in 9 languages, e-signature | Line ball. OpenSolar’s CRM and payments layer is deeper |
| Price against value | 10. Free, unlimited users and projects | 6. $1,299 per user per year at five seats | OpenSolar wins outright. No argument available |
| Support and onboarding | 7. Community-weighted, very fast to learn | 8. Contracted support, faster response | SurgePV wins narrowly |
| Total | 37 / 50 | 41 / 50 | Four points, all of them engineering output |
SurgePV’s named weaknesses. Brand recognition is thin because it launched in 2025, so a new designer will not arrive already trained on it, whereas OpenSolar has 28,000 users to hire from. There is no drone capture, so as-built and survey workflows need a separate tool. There is no structural stamping, so anything needing a professional engineer’s seal goes to an engineering partner. The racking database is thinner than the module and inverter databases, which means manual entry on unusual mounting systems. And it costs money, which against a free competitor is the objection that matters most.
The honest summary: SurgePV is worth paying for when your work produces engineering deliverables that the free tools on our bench did not cover. If your work does not produce those deliverables, you are buying capability you will not invoice for, and OpenSolar is the better business decision. That is a sentence we would rather not write, and it is still true.
How Heaven Green Energy Uses This In Practice
We run a 12-person engineering team across residential, commercial and industrial projects, and we have watched several installer partners run entirely on OpenSolar. Three things we have learned that do not appear in vendor material.
The break point is the deliverable, not the company size. We have seen a seven-person residential crew be perfectly served by OpenSolar and a two-person consultancy be badly served by it, because the consultancy’s product was a yield report. Ask what you hand the customer at the end. If it is a proposal, OpenSolar is enough. If it is a document an engineer will argue with, it is not.
The second-tool moment arrives with the first commercial enquiry. Every partner we have watched added a simulation tool the month they quoted their first job over about 250 kW. Plan for it rather than discovering it mid-tender. That is where a paid platform starts earning its licence, and it is why our own design work runs through SurgePV.
Free changes behaviour, usually for the better. Because seats cost nothing, small teams put their sales staff in the design tool. That produces faster quotes and, occasionally, a proposal with an optimistic shading assumption that nobody senior checked. Set an internal review rule before you set the seat count. We run string voltage checks through the free QBits Energy string sizing calculator as a second pair of eyes regardless of which platform produced the design, because the failure mode of an unchecked design is an inverter, not an argument.
For the wider picture, our free solar design software roundup covers every no-cost option and where each one stops, our solar proposal software guide covers the closing layer specifically, and the OpenSolar alternatives comparison ranks what installers move to when they outgrow it. OpenSolar remains, in our assessment, the best free solar design software available in 2026 and a serious product regardless of price.
Frequently Asked Questions
Is OpenSolar really free, or is there a catch?
It is really free for the full workflow inside the platform: design, proposals, e-signature and CRM, with unlimited users and unlimited projects. The funding comes from manufacturers, distributors, finance companies, permitting providers and training partners who pay to reach the installer network. The one boundary that is no longer free is data leaving the platform. Since 16 April 2026 OpenSolar charges for API Access and Connectors to external CRM, accounting and reporting systems, and it has not published those rates.
How does OpenSolar make money if the software is free?
Partners on the supply side pay for access to the installer network. Hardware manufacturers and distributors want their products specified in designs and ordered through the platform. Finance companies want their loan and lease products offered inside proposals. Permitting and training providers want to reach the same audience. OpenSolar also sells bespoke software services to manufacturers and finance companies serving dealer networks, and charges for API access.
Is OpenSolar good enough for commercial solar projects?
For small commercial rooftops up to roughly 100 to 250 kW where the customer wants a proposal rather than an engineering report, yes. Above that it stops being appropriate. As of August 2026 we found no module-level 8,760-hour simulation with a loss tree separating shading, soiling, mismatch and thermal effects, which is what a lender or a technical reviewer will usually ask for. On our bench it also scores low on single line diagrams and bill of quantities. Most installers add a second tool at their first genuinely commercial enquiry.
OpenSolar vs Aurora Solar: which is better?
They answer different questions. Aurora is stronger on engineering depth, LIDAR-derived roof geometry and US permit-ready plan sets, and charges $135 to $220 per user per month billed annually. OpenSolar is free, covers proposals and CRM better, and works in 185 countries. If you are a US residential team producing permit packages in-house, Aurora earns its price. If you are a small residential shop anywhere in the world, OpenSolar does the job for nothing. Our Aurora Solar review scores that side in detail.
Does OpenSolar do shading analysis?
Yes, but at a residential sales standard rather than an engineering standard. It models obstructions and produces a shading-adjusted yield estimate that is reasonable for a homeowner proposal. We did not find an hour-by-hour, module-level shading loss breakdown of the kind lender technical reviews usually expect, nor a separation of shading loss from soiling and mismatch that an engineer can audit. For projects where the yield number will be challenged, use a dedicated simulation tool alongside it.
What happens to my data if OpenSolar changes its terms?
You can export project data, and the platform remains free for work created and retained inside it. What changed in April 2026 is that automated movement of data to external systems through the API or built connectors became a paid capability. The practical protection is to keep a periodic manual export and to avoid architecting business-critical automation across the API boundary unless you have priced it. This is the standard platform risk of any free tool, not something unique to OpenSolar.
Who should not use OpenSolar?
Anyone whose deliverable is an engineering document rather than a sales proposal. That covers consultancies producing yield reports, teams producing permit packages in-house at volume, commercial and industrial designers working above roughly 250 kW, utility-scale developers, and any business that needs a contractual support response time. For those readers a paid platform is cheaper than the workaround, and our best solar design software ranking sets out the options.
Is OpenSolar available in India?
Yes. OpenSolar operates in 185 countries and Indian installers use it, though the depth of local tariff and DISCOM modelling varies by state and is thinner than a platform built with India in mind. For rooftop work under the PM Surya Ghar scheme, check that the subsidy and net metering logic matches your DISCOM’s current rules before you send a proposal, and see our India solar design software comparison for platforms with deeper local libraries.
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