Better support small installations (balcony / mini PV) in drawing phase

[georg-d]

As OpenPV is again and again recommended for yield estimation, I tried OpenPV for my mini / balcony PV installation ("steckfertige Solaranlage" / "Balkonsolar") and felt strong demand for improvement in the drawing phase. Here the feedback asked for in https://freiburg.social/@magro@muenchen.social/112648097811113395

For such a small installation, I cannot simply draw roughly but I must draw quite exactly because of

1. the small available space. Many balcony parapets are less than 1m high, so just 0.2m misplacement do mean more than 20% error, while for many roofs it means less than 2% error (many roofs span 10m or more).
2. the legal and security restrictions enforce a small panel area. For example, in Germany, panels are limited to max 2kWp by law, at minimum 1.1m balcony width must stay clear for firemen,... So just 0.5m² deviation of the darwn area from the factual area causes massive miscalculation if only 2 usual solar panels are installed, while it does not matter much for installations of 20 panels.

Drawing sufficently exactly is currently very difficult. Improvement ideas which can be combined:

• At top left, add a new button "Add solar panel 1.7x1.1" and clicking it will add a rectangle of that size, which can be dragged & dropped on the screen to place it accordingly. This will be easiest for those users that plan to buy 1-4 panels of usual size - just click the button, get ready-made appropriately sized rectangle, move it, done.
• After 1st point was set, show a dashed line between last point and mouse cursor, and show the line length next to the mouse cursor, so I can draw relatively exactly a rectangle of e.g. 3.24m width and 0.90m hight (size of 6 WeDoSolar Light panels in portrait orientation). This will be easiest for those users that plan to buy panels of unusual size to match well with the balcony parapet or with the wall part with minimal shade.
• I you've more ideas, please comment 🙂

[FlorianK13]

Hi @georg-d and thanks for your feedback. Standard module sizes as a second option besides free drawing is something that we have in mind for quite some time. Probably some drop down menu like this one would be nice in the UI, where different panel sizes can be chosen.