Good 3D solar design software has to model your real roofs, show shading through the year, size the structure and strings, and produce a priced bill of materials, not just a nice picture. The quickest way to judge any tool is to give it one awkward roof from your own pipeline and see what it can do.
1. Test it on a hard roof, not a demo house
Pick a real site: an L-shaped terrace with a water tank, a stair room and a neighbouring building to the south. Then check each point below.
2. Roof types and outlines
- Flat, gable, shed and hip roofs.
- Outlines that are not rectangles: L, T and U shapes. A hip roof on an L-shaped house is a classic place for tools to break.
- Extra wings and upper storeys on the same building.
3. Everything that casts a shadow or blocks space
- Water tanks, stair rooms, AC units, solar water heaters, dishes, vents and skylights.
- Trees and neighbouring buildings.
- Parapets and other rows of panels.
4. Shading across the year
A shadow picture at noon is not a shading analysis. Ask whether every module is checked against the sun's path through the year, and whether the loss is reported by month. Ask where the climate data comes from, and whether a figure is calculated or assumed.
5. Structure and wind
Rooftop arrays are lifted by wind, so the structure matters as much as the panels. A proposal-level tool should show the wind speed it used and where it came from, the pressure at the height of the array, and the steel it implies. In India that means the basic wind speed from IS 875 (Part 3). Read . A tool should say clearly that a structural engineer still designs the actual roof.
6. Strings and inverter
String design depends on the module datasheet and on the coldest morning and hottest afternoon of the site. A tool that sizes strings from a fixed rule of thumb will be wrong somewhere.
7. A bill of materials that drives the price
Look for quantities counted from the drawing (modules, strings, cable runs, structure, clamps, anchors, earthing) and priced from a rate card you can edit. If the price is just a rupee-per-watt figure typed in, the design does not affect the quote.
8. Can you use it on site, on a phone?
Many sales decisions are made on the roof. Check that the tool works in a phone browser, that panels can be placed by tapping, and that you can show the customer the result there.
9. What comes out at the end
- A proposal with the layout, orientation, wind and structure, warranty, payment schedule and a payback figure.
- Subsidy worked out by the current rule, with DCR and non-DCR modules treated differently where that matters.
- A link or a file the customer can open, and a design that carries into the quotation without retyping.
How RAYVO does this
RAYVO's studio draws flat, gable, shed and hip roofs of any outline, places tanks, trees and neighbours, checks shading month by month, shows the IS 875 wind speed and pressure, sizes inverters and strings, builds a priced bill of materials and a proposal PDF, and works on a phone. See the , and run your own awkward roof through it and any other tool you are considering.