Thursday, 7 July 2011

Solar irradiation map

Definition of solar irradiation : rays which are emitted by the Sun. (

If you've ever wondered how effective a solar oven would be in your area, there is now global map available on-line.

This is the map for Southern Africa:
For other Global maps please go to:
The maps of Global horizontal irradiation (average sum 2004-2010) for Africa and Europe are available to download here. SolarGIS database is the source of solar data represented on the maps.

The maps are free for public use, their reproduction and adaptation is authorised provided the following source is acknowledged:  
SolarGIS © 2011 GeoModel Solar s.r.o.

At the moment SolarGIS don't seem to have maps for the US of A, Asia or Australia/ New Zealand - perhaps you could contact them to query?  (They are based in Slovakia.)

Alternatively, from this site I found this map:
World Daily Solar Insolation Map.
This map shows the amount of solar energy
in hours, received each day on an optimally
tilted surface during the worst month of the year.
But, to give you an idea of what the first map means - we are in a 1700 - 1900 kWh/m2 area (on the second map we are in the 4.0 - 4.9 or Zone 2 range) and I have no problem reaching temperatures of 200°C (400°F) in my solar oven in summer.  Unfortunately, I am unable to give you temperatures in winter as our (town) garden only receives approximately 1½ - 2 hours of sun - right at the bottom of our garden.

On the farm - I don't know at the moment, but I should be able to tell you by the 20th July - RMan shares his birthday with Mr Mandela, and he (RMan, that is) has decided that he'd like to spend it on the farm :-)  Although Mr Mandela is very welcome too...

So, if all goes according to plan, I will be schlepping the solar oven along.  Reckon it will be a very interesting experiment.  Discovering just how much I can use the solar oven in winter will be a b-i-g plus for our off grid life...


  1. I live in an area that is said to have less than 100 days of sun a year, and they do not recommend solar power. We have had sun for months (and of course no rain) and as someone who is running the whole house on solar power, that is so not true. So you cant always go by what the experts recommend.

  2. Near as I can tell from that second map we are in the 1.0 - 1.9 section. I guess that means if the sun starts to cool we will be the first to freeze.:)

  3. Jane - that's interesting! And I know that you use your solar oven.

    Just goes to prove - don't give up on something before you try :-)

  4. Mr H - Dunno about the sun cooling - but if the next little ice age knocks on the door, you may have a little problem.

    But, as Jane said, she's not supposed to have enough sunlight to generate solar power, but she runs her whole house of it.. Have you tried doing anything with solar?


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