Optimal orientation and tilt
If the modules can be oriented freely (flat roof, raised structure), Radiaris calculates the orientation that maximises the annual irradiation on the module plane.
How it is calculated
By numerical sweep: a grid of angles is tested and the combination that maximises the annual irradiance on the plane (POA) is chosen, using the weather data of the location and the chosen transposition model.
| Mode | Sweep |
|---|---|
| Tilt only | Tilts from 0° to 60° with the plane azimuth fixed |
| Tilt and azimuth | Tilts from 0° to 60° and azimuths in the range of the corresponding hemisphere |
Azimuth convention: 0° = north, 90° = east, 180° = south, 270° = west. The azimuth range adapts to the latitude (northern or southern hemisphere).
What is changed
The result does not overwrite the tilt or azimuth of the roof (which describe the real physical roof). It is saved separately as the tilt and azimuth of the modules, which are the ones used for the simulation. The roof drawing uses the plane values and the module drawing uses the module values.
When it is worthwhile
- Flat roof or ground: almost always. The optimal annual tilt depends on the latitude, and for self-consumption a lower tilt may be better to produce more in summer and less in winter.
- Pitched roof with flush modules: not applicable; the orientation is that of the roof.
Energy optimum is not economic optimum
Maximising annual energy does not always maximise NPV: steep tilts require more row spacing and fewer modules fit per square metre. Compare both options with the scenario comparator.