Reference
The equipment files and other files SolarLayout Rooftop reads, its limits, and the words the pages use.
This page gathers what SolarLayout Rooftop reads from each file you give it, the limits it holds a design to, and the words these pages use. The steps' own pages say where each file is chosen and what each value changes.
Equipment files
Rooftop sizes the layout, the strings and the energy from two PVsyst files: a module file (PAN) and an inverter file (OND). Choose them from the app's library, or give your own: the module on the Array step's Module, the inverter on the Strings step's Inverter. Each is chosen with Change, in the window Choose a module or Choose an inverter.
A file chosen, from the library or your own, goes with the design: its text is kept in the design and in its project file. The section then says Yours.
Module file (PAN)
The app reads the maker and the model, PNom, Width and Height, Technol, NCelS, NCelP, NDiode, the
half-cell layout, Isc, Voc, Imp, Vmp, muISC, muVocSpec (or muVoc), muPmpp, the one-diode parameters,
VMaxIEC (or VMaxUL), BifacialityFactor, the LID loss and the IAM profile.
| What the file gives | What it sets |
|---|---|
The size (Width, Height) | With the orientation, each position's footprint on the roof. Values of 100 or more are read as millimetres; the longer side is the length |
Voc, its coefficients and the highest voltage | The string length. Without VMaxIEC or VMaxUL the module's highest voltage is taken as 1000 V |
| The currents | The strings one MPPT takes |
The power (PNom) | The kWp and the energy |
BifacialityFactor | The rear's gain on a bifacial module |
| The LID loss | The light-induced degradation in the energy; 1.5 % when the file gives none |
| The IAM profile | The light lost to reflection off the glass; a standard curve when the file gives none |
The file is read as UTF-8, else Latin-1, else cp1252. The chooser takes .pan files. A file over 256,000 bytes is
refused before it is sent.
A file without PNom, Voc or Isc is refused, and the module of before stays. A file without Width and
Height is read, with a note: the layout needs the module's size, so choose a PAN file that has it. See
Module.
Inverter file (OND)
| What the app reads | What it is used for |
|---|---|
| The maker and the model | The inverter's name on the card, in the report and in the bill of materials |
PNomConv | The nominal AC power: each option's DC/AC ratio and its number of inverters |
The MPPT window, its minimum and VMPPMax | The shortest string, and the longest the MPPT takes |
VmppNom, the nominal MPP voltage; when the file gives none, the middle of its VNomEff, the voltages its efficiency curves are given at | The options try the string length nearest it; with neither, the longest length stands for it |
VAbsMax | The inverter's highest DC voltage, one of the limits on a string (VMPPMax when it gives none) |
| The number of MPPT and of inputs | The strings one inverter takes |
IMaxMPPT, else IMaxDC divided by the MPPT | The current one MPPT takes. Enter the datasheet's value on the Strings step when the file gives neither |
| The efficiency curves | The inverter's loss at each hour; its European efficiency without curves, else 97 % |
| The threshold power and the night consumption | The inverter's output at low light and at night |
| The highest AC current and the output voltage | The AC cable in the bill of materials. 415 V AC when the file gives no output voltage |
| The width and depth | The inverter's rectangle in the CAD layout; a 2 × 1.2 m block when the file gives none |
The file is read as UTF-8, else Latin-1, else cp1252. The chooser takes .ond files. A file over 256,000 bytes is
refused before it is sent. A file without PNomConv or VMPPMax is refused, and the inverter of before stays. See
Inverter.
The library
| Modules | Inverters | |
|---|---|---|
| Search | The maker, the model, the file's name or the power in Wp | The maker, the model, the file's name or the power in kW |
| Filter | Power (Wp) | AC power (kW), MPPT, Max DC (V) |
| Columns | Module, Wp, Efficiency %, Size m, Bifacial | Inverter, AC kW, MPPT, MPPT V, Max DC V |
The list opens by power, low to high; a column's head sorts it. An inverter file its maker calls preliminary is tagged Preliminary. An inverter rated under the system voltage carries an exclamation mark and "Up to <r> V: strings sized to <r> V, not <V> V". An entry chosen from the library is tagged In this design.
A new design starts with the app's own module, BiN-08-580 by Waaree (580 Wp, 2.278 × 1.134 m, bifacial), and its own inverter, WP-330KTL-H1 (275 kW, 6 MPPT, 28 inputs). The module is also in the library; the inverter is not.
Other files Rooftop opens
Drawings (KMZ, KML, DXF)
Import a drawing, on Home or in the project menu, opens a drawing of the roof as a new design on the Roof step. The design is named after the file, without its ending, and its roof type is Flat, rows facing south (north south of the equator). See Import a drawing.
| KMZ, KML | DXF | |
|---|---|---|
| Read | Each placemark's polygon (its outer boundary) and line. In a KMZ, the first KML inside it | Closed polylines (LWPOLYLINE, POLYLINE) and circles in the model space, ASCII or binary. Open lines, arcs and blocks are not read |
| The roof | The largest polygon | The largest closed polyline |
| The obstacles | The other polygons: a box when it is a rectangle, else a building beside the roof. Lines are walls | The other closed polylines; circles are tanks |
| Names | The placemark's name, else "Obstacle <n>" | The layer's name |
| Where the roof is | The polygon's own coordinates; the roof's centroid is the design's place | Not in the file: give the latitude and longitude in the dialog. Choose m or mm for its units |
A height is read from a shape's name, written h=2.5 or h:2.5, and from a KMZ placemark's description. An
obstacle without one is given 1.0 m and listed to review on the Roof step: type its real height there.
The folder "Modules (<n>)" of the app's own Google Earth model is left out.
A drawing of about 4.7 MB at most can be sent. The KML inside a KMZ may be 20 MB at most. Save a drawing with only the roof and its obstacles if it is larger.
Weather (CSV)
On Performance, Weather ▸ Your file opens Load weather from a CSV. The file is one year of weather, hourly or more often, with times in UTC.
| Column | Names read (any case) | Unit | Needed |
|---|---|---|---|
| Time | time, time(utc), datetime, date, timestamp, date/time | UTC | Yes |
| Global irradiance (GHI) | ghi, g(h), gh, global_horizontal, allsky_sfc_sw_dwn, irradiance | W/m² | Yes |
| Beam (DNI) | dni, gb(n), bn, allsky_sfc_sw_dni | W/m² | No |
| Diffuse (DHI) | dhi, gd(h), dh, diffuse, allsky_sfc_sw_diff | W/m² | No |
| Air temperature | temp_air, t2m, temp, temperature, tamb, t_amb, ambient_temp | °C | No |
| Wind | wind_speed, ws10m, wind, ws | m/s | No |
- Size: 3,000,000 bytes at most;
.csvor.txt. A year is under 3 MB even at 15-minute steps. - Length: 8,760 hours, or 8,784 for a leap year, once rows of less than an hour are averaged into hours.
- Times: written as
YYYYMMDD:HHMMor any common date and time, such as2023-06-01 13:00. A time without an offset is taken as UTC; a time with one keeps it. A row's time is the start of its period. An hour given twice is refused. - The separator is found from the file. Blank lines and lines that begin with
#are left out. - Without beam and diffuse (either one missing), both are worked out from the global irradiance (Erbs model), with a note.
- Without air temperature, 25 °C is taken for all hours and the strings are sized for 25 °C; enter the site's lowest and highest ambient on the Strings step. Without wind, 1 m/s.
- Gaps: a blank irradiance cell is refused. Gaps in some temperature rows are filled from the hours either side, with a note. Irradiance below zero is taken as 0.
The file's text goes with the design and its project file, and is checked again at each run. See Option and weather.
Project file (.rtd)
The project file is the whole design in one file: Download the project file in the project menu, on a design's card on Home, or Project file in Handover. Open a project file, on Home or in the project menu, opens it as a new design on this device. See Open a project file.
| Holds | The name and the place's name; the roof, its edges and its obstacles; the array; the losses; the module and inverter files' names and text; the weather's source, any CSV and the weather's hours; the system voltage and who set it; the sizing temperatures, the current per MPPT and the Voc coefficient where set; the chosen option and your own option; the AC cable length |
| Does not hold | Any result: the layout, the energy, the options and the files are worked out again when it opens |
| Format | JSON, format version 2. The app reads formats 1 and 2 |
| Size | About 6 MB at most as it is sent; the text 5,000,000 characters at most. The weather's hours take most of it: the demo's file is 680 KB |
| A file without a system voltage | Opens with the voltage of your country, set by the app |
| A file of format 1 that names a file without its text | Opens with a note for each: "The module file <name> (PAN) is not included in this project. Choose it again." (or the inverter file, or the CSV weather file) |
The embedded weather is used again when its source is the design's and its place is the roof's. Otherwise the app loads the weather again for the roof's place.
Limits
| Item | Limit |
|---|---|
| Roof | 30,000 m² (about 3 MWp). One roof a design: outline each building of a larger site as its own design |
| Corners of an outline | At least 3 |
| An edge typed on Find | 0.1 to 2,000 m |
| A roof by hand | Length and width 0.1 to 2,000 m; corners −5,000 to 5,000 m from the place |
| Obstacle height above the roof | 0.05 to 200 m |
| Box | Length and width 0.1 to 500 m; its corners must make a rectangle |
| Tank, tree | Diameter 0.1 to 100 m; a tree's crown starts 0 to 100 m above the roof |
| Wall | At least 2 points; thickness 0.05 to 5 m |
| Building beside the roof | At least 3 corners |
| Modules on the roof | No limit but the roof's room |
| Your own option | 1 to 200 inverters |
| Design name, place's name | 200 characters; a design needs a name |
| Downloaded file names | The first 80 characters of the design's name |
| Module file (PAN), inverter file (OND) | 256,000 bytes |
| Drawing (KMZ, KML, DXF) | About 4.7 MB; the KML inside a KMZ 20 MB |
| Weather CSV | 3,000,000 bytes; 8,760 or 8,784 hours |
| Project file (.rtd) | About 6 MB as sent; 5,000,000 characters |
| Places listed by a search | 5 |
| Undo | The last 50 edits |
| Use my location | Waits 15 s for the browser |
| Weather downloads | PVGIS waits 60 s, NASA POWER 120 s |
| A run | Begins 500 ms after the last change |
Glossary
| Term | What it means here |
|---|---|
| Ageing | The energy lost each year as the modules age, in % a year (degradation) |
| Area kept clear | The part of the roof the shadows of the parapet and the obstacles cover in the shade-free hours of the design day. No module stands there unless Allow shaded positions is on |
| Bifacial rear gain | The energy a bifacial module takes from light on its back |
| Clearance | The space kept free of modules round each obstacle |
| Clipping | The energy lost when the DC power is more than the inverter's AC power can pass |
| Conservative (P90) | The energy of year 1 that the design reaches 9 years in 10 at least |
| CUF | Capacity utilisation factor: the year's energy against the inverters' AC power for 8,760 hours |
| DC/AC ratio | The modules' DC power (kWp) against the inverters' AC power (kW). Options aim at 1.10 to 1.30 |
| Design day | The day the rows are spaced for. At first the winter solstice: 21 Dec north of the equator, 21 Jun south of it |
| Direction (azimuth) | The way the rows, or a sloped roof, face, in degrees clockwise from north |
| Drawing | A file of the roof's outline and obstacles: KMZ, KML or DXF |
| Edge margin (setback) | The strip kept free of modules along the roof's edges |
| Handover | The files for the client, the installer and the utility |
| Horizon shading | Sunlight lost to hills and buildings far away, from the site's horizon |
| IAM | Incidence angle modifier: the light lost to reflection off the glass when the sun is low on it |
| Imp, Isc | A module's current at maximum power, and its short-circuit current |
| Inverter file (OND) | The PVsyst file of an inverter's ratings |
| kWp | The modules' power at standard test conditions (STC) |
| LID | Light-induced degradation: the module's loss in its first months of sunlight |
| Likely (P50) | The energy of year 1 the design reaches one year in two at least: the year-1 figure itself |
| Module file (PAN) | The PVsyst file of a module's ratings and size |
| Modules in tilt | How many modules stand one above another up each row |
| Modules per string | How many modules are wired in series in one string |
| MPPT | Maximum power point tracker: an inverter input that takes a group of strings |
| Near shading | Sunlight lost to the rows and the obstacles on the roof |
| Obstacle | What stands on the roof or beside it: a box, a tank, a wall, a tree, a building |
| Option | One way to wire the modules to the inverters, lettered from A, the best first |
| Orientation | Portrait or landscape: which side of the module runs up the row |
| Outline | The roof's edge, traced on the map or typed by hand |
| Parapet | The low wall along the roof's edges. It casts shadows like an obstacle |
| Performance ratio (PR) | The energy to the grid against what the modules' rated output would give in the sunlight on them |
| Position | A place on the roof where a module fits. An option may leave some empty |
| Present | The design as a tour on the whole screen, for a client |
| Project file (.rtd) | The whole design in one file, to open again in the app |
| Roof albedo | How much light the roof reflects, as a share of the light on it |
| Roof pitch | The slope of a sloped roof, in degrees |
| Row spacing (row pitch) | The distance on plan from one row's front edge to the next row's |
| Shade-free hours | The hours of the design day in which rows and obstacles must not shade the modules |
| Shade map | Each module coloured by its loss to near shading over the year |
| Soiling | Dirt on the glass, and the light it takes |
| Solar time | The sun's time: noon is when the sun stands highest |
| Sun view | A view of the stage on the Roof, Array and Strings steps: shadows at any hour, and the shade on each module over the year |
| STC | Standard test conditions, at which a module's ratings are given |
| String | Modules wired in series to one input of an inverter |
| String shading loss | The energy lost when a shaded module holds back its whole string |
| System voltage | The highest DC voltage the system may reach: 600, 1000 or 1500 V |
| Uc | The heat loss factor of the cell temperature model, set by the roof type unless you enter one |
| Voc | A module's open-circuit voltage. On the coldest morning it sets the longest string |
| Voc coefficient | How much the Voc changes with the cell's temperature, in %/°C |
| Walkway | A path kept free of modules, after a set number of modules along a row, or of rows |
| Weather | The year of sunlight, temperature and wind: Typical year (PVGIS), 2023, measured (NASA POWER), or your file |
| Yield | The year's energy for each kWp, in kWh/kWp |
| Your own option | An option you add, with your own modules per string, strings and inverters |