Singapore has almost no land, a tropical sky that is cloudier than most people assume, and one of the most orderly solar approval processes in Asia. Those three facts define the design problem. Every project is a rooftop, a facade, or a floating installation, the irradiance is heavily diffuse, and the paperwork runs through a defined sequence involving a Licensed Electrical Worker, the grid operator, and the building authority. Software that assumes open land and clear skies is solving the wrong problem.
Direct answer. The best solar design software in Singapore for most EPCs is SurgePV or PVsyst, because the design problem is dense rooftop layout under heavy diffuse irradiance with tight shading from surrounding high-rise. TR 26 governs grid connection of embedded generation and SS 638 governs the electrical installation, and the submission has to be endorsed by a Licensed Electrical Worker regardless of which platform produced it.
TL;DR
- TR 26 is the technical reference for connecting embedded generation to the Singapore grid.
- SS 638 is the code of practice for electrical installations, replacing the former CP 5.
- A Licensed Electrical Worker must endorse the electrical submission. No software substitutes for that.
- Irradiance is heavily diffuse and seasonality is minimal, so tools with weak diffuse models misestimate yield.
- Shading from surrounding buildings is the dominant loss on urban rooftops, so 3D context modelling matters more than usual.
What Singapore Actually Changes About Solar Design Software
The sky is diffuse, not clear. Singapore sits near the equator with high cloud cover and humidity, which means a large share of the annual irradiance arrives as diffuse rather than direct radiation. Design tools using simplified clear-sky arithmetic overestimate yield. Tools with a proper hourly transposition model handle it. The practical consequence is that tilt optimisation matters less than it does at higher latitudes, and near-horizontal mounting is often reasonable, which in turn raises soiling and drainage considerations.
Shading is architectural. On an urban Singapore rooftop the shading comes from neighbouring towers, plant rooms, and services, not from trees. That makes 3D context modelling and hourly shading analysis the difference between an accurate yield and a fictional one. A tool that models only self-shading between rows will miss most of the loss.
TR 26 governs connection. The technical reference for the connection of embedded generation to the low-voltage or high-voltage network sets the protection, anti-islanding, and metering requirements. The grid operator’s process follows it.
SS 638 governs the installation. The Singapore Standard code of practice for electrical installations replaced CP 5 and is the framework the installation and its documentation follow.
A Licensed Electrical Worker signs. Electrical submissions require endorsement by an LEW of the appropriate class. This is a professional obligation, not a document a platform generates, and it sits at the end of whatever design workflow you choose.
Structural review is real. Rooftop additions on Singapore buildings attract building authority scrutiny, and a Professional Engineer’s structural assessment is commonly required. That is separate engineering.
The Platforms Ranked for Singapore
| Platform | Best for | Diffuse and hourly shading | 3D context modelling | Editable CAD output | Price per seat per year |
|---|---|---|---|---|---|
| PVsyst | Bankable yield and detailed shading | Best in class | Yes, scene builder | No | ~$500 |
| SurgePV | Layout, SLD, and drawings in one license | Yes, 8,760-hour | Yes | DXF and DWG | $1,299 to $1,899 |
| HelioScope | Fast C&I rooftop layouts | Yes | Moderate | DXF only | ~$1,188 |
| Aurora Solar | Complex roof geometry | Yes | Strong | Limited | $1,908 to $3,108 |
| AutoCAD | Final submission drawings | Not applicable | Manual | Native | ~$2,030 |
| SAM (NREL) | Technology sensitivity studies | Yes | No | No | Free |
| Scanifly | Drone capture of complex sites | Inherited | Strong | Yes | ~$3,000+ |
PVsyst is the yield reference and its 3D near-shading scene builder is the right tool for modelling surrounding high-rise obstruction accurately. See PVsyst price.
SurgePV covers layout, string design, single-line diagram, and editable DWG in one license, which is what the LEW-endorsed submission package is built from.
HelioScope is fast for C&I rooftop. See HelioScope pricing.
Scanifly earns consideration where a site is complex enough that drone capture beats satellite geometry. See Scanifly pricing.
Try the software behind this guide
Model the tower next door, not just the roof
SurgePV builds the 3D context, runs 8,760-hour shading, sizes strings, and exports the single-line diagram and editable AutoCAD DWG for the LEW submission pack.
Book a free SurgePV demo →No credit card. 20-minute walkthrough on one of your own projects.
What a Singapore Design Package Has to Contain
- Layout with module positions, tilt, and clearance from plant, services, and access routes.
- 3D shading study including surrounding buildings, with hourly loss quantified.
- Single-line diagram with protection, anti-islanding, and metering to TR 26.
- Electrical documentation consistent with SS 638.
- LEW endorsement of the electrical submission by a licensed worker of the appropriate class.
- Structural assessment by a Professional Engineer where the building authority requires it.
- Grid operator application for the embedded generation connection.
- Fire safety and access provisions consistent with the building’s requirements.
Item 2 is the one that separates realistic Singapore yield estimates from optimistic ones. On a rooftop overlooked by taller buildings, obstruction shading can dominate the loss budget, and it cannot be estimated without modelling the surroundings.
Pricing in Singapore Dollars
| Stack | USD per year | Approx. SGD at 1.34 | Covers |
|---|---|---|---|
| PVsyst | ~$500 | ~S$670 | Yield and detailed shading |
| HelioScope | ~$1,188 | ~S$1,592 | C&I layout and yield |
| SurgePV | $1,299 to $1,899 | ~S$1,741 to S$2,545 | Layout, SLD, DWG, proposal |
| PVsyst plus SurgePV | ~$1,799 to $2,399 | ~S$2,411 to S$3,215 | Bankable yield plus drawings |
| Aurora | $1,908 to $3,108 | ~S$2,557 to S$4,165 | Proposal-led stack |
Exchange rate is illustrative.
What Most Singapore EPCs Get Wrong
They model the roof and not the skyline.
A yield estimate built from array geometry alone, without the surrounding towers in the scene, will overstate production on a large share of Singapore rooftops. The error is not marginal. On a mid-rise building among taller neighbours, obstruction shading can remove a substantial fraction of morning or afternoon generation, and it shows up in the first performance review rather than in the design.
The second mistake is over-optimising tilt. Near the equator with heavily diffuse irradiance, the yield gain from precise tilt optimisation is small, while the cost in mounting complexity, wind exposure, and roof loading is real. Simpler mounting frequently wins.
When Software Is Not the Answer
Singapore rooftop projects routinely need a Professional Engineer’s structural assessment, and that is engineering rather than software. Older buildings, in particular, need their capacity established before any layout is meaningful.
Our solar civil and structural engineering team produces those assessments, with calculations via STAAD Pro report calculations, and solar rooftop detailed engineering design covers the full construction pack. See the sample design pack or talk to our team.
Conclusion
- Put the surrounding buildings in the shading model. Obstruction shading, not row shading, is the dominant Singapore loss.
- Do not over-optimise tilt. Diffuse-dominated equatorial irradiance rewards simple mounting more than precise angles.
- Plan the LEW endorsement and structural PE review into the schedule. Neither comes out of software.
In this country series: solar software in Singapore, best solar proposal software in Singapore, shading analysis software in Singapore, Helioscope review. Tool deep dives: Aurora Solar review, Opensolar review.
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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
What is the best solar design software in Singapore? PVsyst for bankable yield and detailed obstruction shading, paired with SurgePV for layout, single-line diagrams, and CAD export. HelioScope is a faster option for straightforward C&I rooftops.
What is TR 26? The technical reference governing connection of embedded generation to the Singapore grid, setting protection, anti-islanding, and metering requirements.
What replaced CP 5 for electrical installations? SS 638, the Singapore Standard code of practice for electrical installations, is the current framework.
Does software replace the Licensed Electrical Worker? No. Electrical submissions require endorsement by an LEW of the appropriate class. Software produces the drawings and calculations that the LEW reviews and endorses.
Why does diffuse irradiance matter so much in Singapore? Because near the equator with high cloud cover, a large share of annual irradiance arrives as diffuse rather than direct radiation. Tools with simplified clear-sky models overestimate yield.
How much does solar design software cost in Singapore? From roughly S$670 per year for PVsyst alone to around S$4,165 for a proposal-led stack. Full math is in our solar design software pricing breakdown.
What about proposal software specifically? Covered in best solar proposal software in Singapore.
What about shading analysis specifically? Shading is a separate tool decision at Singapore’s latitude and approval regime. Covered in best solar shading analysis software in Singapore.
