[Qgis-user] solar potential

[Szabo Szilard]

Dear All,
Thank You for your comments and suggestions. I tried several options and
softwares (ArcGIS, SAGA, GRASS) and as a validation, have a correct
calculation based on equations being used for solar panels. So far, it
seems that ArcGIS provided the best correlation, SAGA did somethibg strange
(strong but negative correlation) and GRASS provided data having no
correlation ... Of course, it is not a thorough and comprehensive review I
will continue  - it is just a report for You after my question. None of the
softwares approximated the values calculated with the eqations just can be
approached with linear regression.

Both SAGA and GRASS calculated lesser solar income for southern roof panels
than eastern and western, and also, northern roof panels had high values,
too ... I am quite sure that I am missing something but for now, data seems
unreliable for me. Actually, I used the GRASS through QGIS, so it can be a
next step to try the native software itself.

Thank You for all you, if i figure out the solution I share it with you, if
someone is interested in.

Szilard

2015-03-04 9:19 GMT+01:00 Siki Zoltan <siki at agt.bme.hu>:

> Hi Szilard,
>
> did you try the nativ GRASS command without QGIS toolbox?
> Zoltan
>
>
> On Tue, 3 Mar 2015, Szabo Szilard wrote:
>
>  Hi!
>> Does anyone has some experience with the r.sun GRASS option (Processing
>> toolbar). I am strugling with the results because they are not reasonable.
>> Data can be calculated for a day and in January the solar income is
>> greater
>> than in July ...
>> I have tried with a national CRS (EPSG 23700) and with WGS84 (4326) but
>> all
>> output seems a bit strange (too small and the issue of January-July).
>>
>> Do you have idea what am I doing wrong?
>> DSM: 20 cm resolution
>> objects: a building with roof planes derived from photogrammetric
>> technique
>> QGIS 2.6.1
>> Win 8.1
>>
>> DSM is here (EPSG 4326):
>> https://share.tresorit.com/?0024vtkidgwfi9ib4u02i883&
>> GNNzY6Ig7hqNHeIFeYPP69CIIDynxO9L&1&dXVQoIiKa3juWxNm8I4UnbvuUffB6v
>> oJuoBqxyE9T2GgXjtgfGsmV8FWLKpVPkCl#VQr6AtH1cY2D1VqWMDnokthlHd1AQ5
>> I4sLWQ7+EUlcs=&ZGVtX25lazN3Z3MudGlm
>>
>> Thanks in advance
>> --
>> Dr. Szilard SZABO
>> associate professor, head of department
>> Department of Physical Geography and Geoinformation Systems
>> University of Debrecen
>> https://www.researchgate.net/profile/Szilard_Szabo/?ev=hdr_xprf
>> Publications <https://vm.mtmt.hu/search/slist.php?lang=0&AuthorID=
>> 10000172>
>>
>>


-- 
Dr. Szilard SZABO
associate professor, head of department
Department of Physical Geography and Geoinformation Systems
University of Debrecen
https://www.researchgate.net/profile/Szilard_Szabo/?ev=hdr_xprf
Publications <https://vm.mtmt.hu/search/slist.php?lang=0&AuthorID=10000172>
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