Topic: Potential Maximum Solar Radiation at different Lat/Lng + time of the year.

[iisfaq]

I am sure that there is a potential maximum solar raidation that can appear on a particular day of the year for any Lat/Lng?

Does anyone know if there is a formula to calculate this?

chris

[iisfaq]

I found this reference

http://www.google.co.nz/url?sa=t&source=web&cd=8&ved=0CFAQFjAH&url=http%3A%2F%2Fwww.solarpathfinder.com%2Fdoc%2FHow_To_Doc_Solar_Radiation_NASA_Data.doc&rct=j&q=%20solar%20raidation%20lat%20lng&ei=Z1YZTpaOGcb0gAeLk6gv&usg=AFQjCNGO_BjuP6EftvdbOjg93wNxQCbf_A

But I do not think that this is what I am after.

For my area it produces the following for July

22 Year average is 1.61 kWh/m2/day

The best I have seen this month whas been about 478 w/m2 from my Davis Vantage Pro II on a perfectly clear day.

So 1600 w/m2 per day may be accurate for the whole 9 hours but how to I find out what the potential maximum is per hour?

Obviosuly at midday there is a higher chance of higher solar radiation.

Chris

[iisfaq]

Looks like I have everyone stumped on this question?

[SLOweather]

At any given time, the Davis sensor will have a closer (larger) number to what you are trying to read if it is pointed directly AT the sun, not left horizontal/level.

There is a huge calculation available that will tell you the theoretical solar insolation, given lat, lon, time of day, date and year.

I'll see if I can find it.

[iisfaq]

There is a huge calculation available that will tell you the theoretical solar insolation, given lat, lon, time of day, date and year.

I would appreciate it if you do find it..

cheers

chris

[SLOweather]

Have you read the Wikipedia entry for Sunlight?

http://en.wikipedia.org/wiki/Sunlight

I don't think the info for the calculation will cut and paste here, so look at that section.

[whitenemesis]

How about these files?

http://www.ecy.wa.gov/programs/eap/models.html

solrad is the one you want I think?

[iisfaq]

How about these files?

http://www.ecy.wa.gov/programs/eap/models.html

solrad is the one you want I think?

Great - this one looks to do exactly what I need - now to try to convert the macros

SolRad - A solar position and solar radiation calculator for Excel/VBA.
http://www.ecy.wa.gov/programs/eap/models/solrad.zip

Chris