Detemining solar insolation and using it in calculation of array size

[JNSMAR043]

Hi I am designing a completely off grid system to be used in South Africa. I cant find any reliable solar insolation data on the web can anyone help me with links for any location. All i can find is maps with annual solar sum energy given in MJ/m^2 where as I am looking for monthly averages.

Thanks in Advance

[Wy_White_Wolf]

http://www.gaisma.com/en/dir/001-continent.html

[russ]

Ji JNS - Welcome to Solar Panel Talk!

Try http://www.gaisma.com/en/location/pretoria.html

This page is for Pretoria but many cities are listed. Part way down the page you will fins
Pretoria, South Africa - Solar energy and surface meteorology

6.70	6.10	5.46	4.77	4.21	3.80	4.08	4.78	5.69	5.98	6.29	6.62
0.57	0.55	0.56	0.59	0.64	0.65	0.66	0.65	0.64	0.58	0.55	0.56
22.23	22.11	21.07	18.66	15.25	11.61	11.46	14.61	18.50	20.20	20.85	21.36
3.62	3.50	3.37	3.54	3.74	4.04	4.18	4.74	4.95	4.73	4.31	3.77
134	75	79	56	12	8	3	6	20	75	103	114
13.3	9.9	10.4	7.0	2.4	1.5	0.9	1.9	2.9	8.5	12.2	13.9

These data were obtained from the NASA Langley Research Center Atmospheric Science Data Center; New et al. 2002
Notes: Help. Change preferences.

[JNSMAR043]

Thanks russ and wolf will post more details about the system. I think it will interest a few of the members of this forum. That link mad an office drones day a whole lot better

[J.P.M.]

Hi I am designing a completely off grid system to be used in South Africa. I cant find any reliable solar insolation data on the web can anyone help me with links for any location. All i can find is maps with annual solar sum energy given in MJ/m^2 where as I am looking for monthly averages.

Thanks in Advance

I'd contact an outfit calling itself SESSA - The Sustainable Energy Society of South Africa. They claim to be a section of the International Solar Energy Society (ISES) which I once belonged to. SESSA may not have what you are looking for but I'd wager there is a fair chance they can point you in more directions. They are on the web and sort of in your neighborhood.

Gaisma data is good as far as it goes, but you may need more than monthly averages for serious design work, particularly hourly data, probably in something like a TMY format and extent. For that, I'd suggest contacting the "SolarAnywhere" people also on the web. They cover most of the U.S., but may have world data avail. or know who does or how to get it.

Hope that helps.

Welcome to the neighborhood.

[JNSMAR043]

Do you know if the insolation data provided on the above website (gaisma) is Global horizontal Irradiance or Direct Normal Irradiance or neither?

[J.P.M.]

Does you know if the insolation data provided on the above website (gaisma) is Global horizontal Irradiance or Direct Normal Irradiance or neither?

Global horizontal.