AnsweredAssumed Answered

Area solar radiation - wrong results

Question asked by ampatzi on Jun 16, 2011
Latest reply on Jun 22, 2011 by geonetadmin
Dear All,

Is there anyone with experience in the Area Solar radiation tool of the Spatial Analyst? I was getting some seriously unreliable results so I run a simple analysis using a flat DEM and then compared these with average values based on measurements.

I have included a word file explaining the problem, along with the flat DEM (please use the latitude shown on the word file if you re-run the analysis to check results I provide). I am running the analysis for two days, one typical for winter (16/2) and one for summer (11/6). I also use complete transmission and totally clear sky conditions to compute a value that can be compared to the Extraterrestrial/exo-atmospheric irradiance on horizontal. The results for the Global, Beam and Diffuse irradiances are entirely inaccurate (as an indication, the annual results underestimated the Global horizontal irradiance by 75%) and I would appreciate any help on this.

Keep in mind that I am new in GIS, so please excuse me if I have done something really stupid:).  I am also confused with the name of the tool, what is the difference between the Area Solar Radiation Tool and the Solar Analyst or TopoView that I usually come across in the literature?

Thank you in advance,

Kind Regards