Most software reviews written by a competitor are worthless, because the conclusion is decided before the first paragraph. So here is ours up front. OpenSolar is one of the best products in solar. It is free at the seat, it is fast on residential work, and for a large share of installers reading this, the correct decision is to keep using it and spend the money somewhere else. We build a paid design platform, and we still think that. The interesting question is not whether OpenSolar is good. It is where the ceiling sits, and what happens on the day you hit it.
Direct answer. OpenSolar is a genuinely strong free residential design and proposal platform, funded by transaction and partner fees rather than seat licences. For residential volume work it is very hard to beat on cost per job. Its limits are structural, not sloppy. It is not built for engineering-led commercial work, lender-reviewed yield studies, or permit drawing sets, and those needs arrive together.
TL;DR
- OpenSolar is free at the seat with no per-user subscription, funded through transaction fees and hardware and financing partner integrations.
- On residential design plus customer-facing proposal, it is excellent, and its Australian adoption is not an accident.
- The funding model shapes the roadmap toward the residential sales motion, so engineering-led commercial work is not the target.
- It does not produce permit drawing sets, stamped engineering deliverables, or the kind of yield study a funder reviews.
- If you only do residential at low margin, do not buy paid design software. If you have taken commercial work, one tool is no longer enough.
What OpenSolar Is and Who It Is For
OpenSolar is a browser-based solar design and proposal platform. You trace a roof from satellite imagery, lay out modules, run a yield estimate, and produce a customer-facing proposal in the same session. It also carries workflow features adjacent to a CRM, so a small sales team can run a pipeline without buying a second product on day one.
The target user is clear from the product shape. It is a residential installer selling to homeowners, doing several jobs a week, where the deciding factor is how quickly a rep can turn an address into a document the customer will sign. OpenSolar is built around that loop and optimised for it.
Adoption backs this up. It is very widely used in Australia, which runs the highest-volume and thinnest-margin residential market anywhere, and it has real traction across other residential markets too. In a market where a per-seat licence eats a visible share of job margin, a free tool that does the job well wins on arithmetic alone.
How Free Actually Works, Explained Fairly
OpenSolar does not charge a seat licence. It earns through transaction fees and through hardware and financing partner integrations that sit inside the workflow. That is the whole model, and it is stated openly by the company rather than hidden.
This deserves credit rather than suspicion. It aligns the vendor with installer volume instead of installer headcount. A growing team can add users without a procurement conversation. A new business can start selling before it has revenue. Very few software categories offer that, and solar is better off because one vendor chose to.
It also has a consequence worth understanding before you build a business on it. Revenue arrives when a residential deal transacts through the ecosystem. That is the signal the roadmap responds to. Work that produces no transaction, such as a 900 kW rooftop tender that needs an engineering review, generates no revenue for the platform, so it will never be the priority. This is not a criticism of the company. It is what the funding model is.
What Most Buyers Get Wrong About Free Software
They evaluate the price and ignore the direction.
Here is the concrete mechanism. Every software company allocates engineering hours toward whatever produces revenue. In a seat-licence business, that includes any user willing to pay, so a vendor will build depth for a small number of demanding engineering customers because those seats are worth more. In a transaction-funded business, engineering hours follow deal flow. A feature that helps close 10,000 residential jobs beats a feature that helps 40 commercial designers, every planning cycle, forever.
So the practical question is not “is this free tool good today.” It is “does my direction of travel match this tool’s direction of travel.” If you plan to stay in residential volume, the answers match perfectly and free is the right structure. If you are moving toward commercial and engineering-led work, you are betting on a roadmap that is pointed elsewhere, and the gap widens each year rather than closing.
The second thing buyers get wrong is counting tools instead of counting handoffs. Two tools are not twice the cost of one. They are one cost plus a rebuild step every time a design changes, because the second tool never inherits the first tool’s model.
What OpenSolar Does Better Than Almost Anything Else
Speed from address to proposal. The residential loop is tight, and the tool respects that a rep may be sitting in a driveway. Very few paid platforms are meaningfully faster.
Cost per job at volume. At several hundred residential jobs a year, no seat licence can compete with zero. That is the entire argument and it is a strong one.
Onboarding. A new sales hire can be productive quickly, which matters far more in a high-churn sales team than any single feature.
Proposal quality for homeowners. The customer-facing document is built for a non-technical buyer making a domestic purchase decision, which is exactly the right design target for that audience.
Accessibility. A one-person operation gets the same tool as a large installer. That has probably lowered the cost of residential solar in aggregate.
If your business is residential volume at modest margins, and someone tells you to replace this with a paid tool, ask them to show the arithmetic. Usually there is not one.
Where OpenSolar Runs Out of Road
The limits are about ceiling, not quality. Three of them matter.
Engineering-led commercial work. OpenSolar is aimed at residential volume. It is not the reference tool for engineering-led commercial or utility-scale projects, and it does not claim to be. Once a job involves complex arrays, serious string topology decisions, and losses that have to be defended line by line, you are outside the design centre of the product.
Yield studies a third party will review. When a client, a funder, or a lender’s technical adviser asks for a yield study with stated loss assumptions, they are asking for a document that survives cross-examination. OpenSolar is not the reference tool for a bankable, lender-reviewed yield study. That is a specialist category and it always has been.
Drawing sets and stamped deliverables. OpenSolar does not produce permit drawing sets or stamped engineering deliverables. If a project needs a construction pack, that work happens elsewhere. No amount of proposal polish substitutes for a drawing set.
Notice what these three have in common. None of them show up in residential volume work. All three show up together in the first serious commercial job.
The Transition Point
The transition is a single moment, and most owners recognise it immediately.
A commercial enquiry lands. A warehouse roof, a factory, a school. The client is not a homeowner comparing monthly savings. It is a facilities manager or a finance team, and they ask for two things a residential proposal does not contain. First, a yield study with the loss assumptions written down. Second, a drawing set they can hand to a contractor.
At that point the free residential stack stops stretching. Not because it broke, but because it was never the tool for this. The usual response is to keep OpenSolar for residential and add a second tool for commercial. That works, and plenty of good businesses run exactly that way. The cost is that you now maintain two models of the same project, and every design change has to be made twice.
The alternative is one licence that covers residential design, the shading and simulation depth commercial work demands, and the drawing output the client asked for. That is the case for paying, and it only applies after the transition, not before.
OpenSolar vs SurgePV
| Dimension | OpenSolar | SurgePV |
|---|---|---|
| Cost | Free at the seat, funded by transaction and partner fees | $1,299 to $1,899 per user per year |
| Primary target | Residential volume, design plus proposal | Design, shading, and proposal under one licence |
| Simulation | Built for the residential sales motion | 8,760-hour simulation with module-level shading, mismatch, and string topology |
| Drawing output | No permit drawing sets or stamped deliverables | Single-line diagrams and DWG export from the same model |
| Proposal layer | Customer-facing residential proposal | White-label proposal layer |
| Workflow features | Includes some CRM-adjacent workflow | Design, shading, and proposal in one licence |
| Best fit | Residential installers at volume and modest margin | Installers who have taken engineering-led commercial work |
The honest reading of that table is that the two products are not really competing for the same buyer. They compete for the same buyer at different stages of the same business.
Try the software behind this guide
For the day the first commercial job lands
SurgePV runs 8,760-hour simulation with module-level shading, mismatch, and string topology, then exports the single-line diagram and DWG from the same model, with a white-label proposal layer on top.
Book a free SurgePV demo →No credit card. 20-minute walkthrough on one of your own projects.
When You Should Not Upgrade
This is the part most vendor reviews leave out, so we will be blunt.
If your business is residential only, at modest margin, and you have no intention of taking commercial work, do not buy SurgePV. Do not buy any paid design platform. OpenSolar covers what you need, and a per-seat licence across a sales team is money taken directly out of job margin in exchange for depth you will never invoice for.
Three specific cases where the answer is no. First, a solo installer or small team doing residential only. The licence cost per job is real and the benefit is theoretical. Second, a team whose actual constraint is scheduling, dispatch, or paperwork rather than design quality. Paying for a better design engine does not fix a logistics problem. Third, a business that takes one commercial job a year. Outsource the engineering for that job rather than carrying a licence for 11 months of the year when it sits idle.
Buy a paid platform when commercial work is a repeating part of the book, not a novelty. Our solar design software pricing breakdown has the arithmetic for that decision.
The Verdict
Opinionated version, stated plainly. OpenSolar is the best free product in this industry and probably the single most useful piece of software a new residential installer can adopt. Anyone who tells you otherwise is selling something. It is not, and does not try to be, an engineering platform, and the day your business becomes an engineering business it stops being sufficient on its own.
So the verdict splits by segment rather than landing on a score. Residential volume: use OpenSolar, and put the saved money into operations. Residential plus recurring commercial: you need a tool that runs full-year hourly simulation and produces drawings from the same model, and you should decide whether that is a second licence next to OpenSolar or one licence covering both. Engineering-led commercial as the main business: OpenSolar was never the tool, and that is fine.
For the wider field, see OpenSolar alternatives and the direct Aurora vs OpenSolar comparison. Australian readers should start with best solar design software in Australia.
When the Answer Is Not Software at All
Sometimes the gap is a deliverable, not a tool. A client asking for a construction pack wants drawings, structural detail, and a bill of quantities, produced by an engineering team that will stand behind them.
That is delivery work rather than modelling work. Our solar rooftop detailed engineering design service produces that pack. You can see a sample design pack or talk to our team about a live project before committing to any licence.
Conclusion
- OpenSolar is genuinely excellent for residential volume. Free at the seat, fast, and well matched to the sales motion it was built for.
- Its limits are structural. The funding model points the roadmap at residential transactions, so commercial depth, defensible yield studies, and drawing sets sit outside it.
- Upgrade at the transition, not before. Commercial work in the book is the trigger. Residential only at low margin is a genuine reason to stay free.
More from our network
Disclosure and accuracy note
Commercial relationship. Heaven Designs and SurgePV are part of the same group. Treat our recommendation of SurgePV as a vendor making its own case, not an independent verdict. We have tried to describe every other product fairly, and to say plainly where a competitor is the better choice.
Pricing. All prices are indicative, compiled from public sources when this page was written. They vary by tier, region, contract term and exchange rate, and change without notice. Several vendors quote rather than publish, and some price in currencies other than the US dollar, so a converted figure moves with the exchange rate. Confirm current pricing with the vendor before you decide anything.
Trademarks and corrections. All product names and trademarks belong to their respective owners, and are used here for identification and comparison only. Their use does not imply affiliation with or endorsement by those companies. If anything here is out of date or wrong, tell us and we will correct it.
FAQ
Is OpenSolar really free? Yes, at the seat. There is no per-user subscription. The company earns through transaction fees and through hardware and financing partner integrations rather than licences. That is a different economic model, not a hidden price on the seat itself.
Is OpenSolar good enough for residential work? For most residential installers, yes. Design plus customer-facing proposal is what it was built for, and it does that job well. Its very strong Australian adoption in the world’s most price-sensitive residential market is the best evidence available.
Can OpenSolar handle commercial projects? It is aimed at residential volume and is not built for engineering-led commercial or utility-scale work. Small commercial jobs may pass. Anything requiring detailed string topology analysis or a defensible loss breakdown needs a different tool.
Does OpenSolar produce permit drawings? No. It does not produce permit drawing sets or stamped engineering deliverables. That work is done in a separate tool or by an engineering team, and it is the most common reason installers add a second product.
When should I move from OpenSolar to SurgePV? When commercial work becomes repeating rather than occasional. SurgePV costs $1,299 to $1,899 per user per year and covers design, shading, and proposal in one licence, with 8,760-hour simulation and DWG export. Below that trigger, staying free is the better call.
What does SurgePV do that OpenSolar does not? SurgePV runs 8,760-hour simulation with module-level shading, mismatch, and string topology, and produces single-line diagrams and DWG export from the same model, with a white-label proposal layer. OpenSolar is not built for drawing output or engineering-led commercial work.
Related: the full field is in OpenSolar alternatives, the head to head paid comparison is in Aurora vs OpenSolar, and the cost picture across platforms is in solar design software pricing.
