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This gives a good overview. What people miss is that during the summer the sun is up all the time. (In the winter, not so much.) And average cloud cover is also

This gives a good overview. What people miss is that during the summer the sun is up all the time. (In the winter, not so much.) And average cloud cover is also accounted for. http://re.jrc.ec.europa.eu/pvgis/countries/europe/EU-Glob_opta_presentation.png http://re.jrc.ec.europa.eu/pvgis/countries/europe/EU-Glob_op...

DamonHD 9y ago
PVGIS is an excellent tool and I have been using it for years!
shandor 9y ago
Thanks! That is quite surprising, and very encouraging. It seems that solar is a very good overall fit for even most of the world, and once the tech is good enough to be used in huge numbers the differences can probably be compensated with other, local power sources (like hydro in Scandinavia, which is huge there).
kodfodrasz 9y ago
Do I understand correctly that the wishful thinking value of 75% photovoltaic conversion efficiency is plotted in the diagram?
- ju-st 9y ago
  It means the conversion factor of yearly yield in kWh to installed PV in kWp. "Yearly sum of solar electricity generated by 1 kWp system". It's not about the physical PV efficiency.
  - deleted 9y ago
    [deleted]
- baking 9y ago
  The 75% performance ratio represents system losses not module efficiency. So a system rated at 1kW(peak) which may be 5-6 square meters in size, and which is exposed to annual sunlight of 1200 kWh/m2 might only produce 900 kWh of usable power. So efficiency has to do with the rated power per surface area and the performance ratio reflects all the system electrical and environmental factors that reduce the amount of usable power below what would be expected based upon module ratings and annual sunlight exposure.
hanoz 9y ago
That diagram suggests Northern Sweden to Southern Europe is 50%, not 80%, which sounds more plausible.
philh 9y ago
> What people miss is that during the summer the sun is up all the time. (In the winter, not so much.) It sounds like these two effects should cancel each other out. Are you saying that people take winter into account but not summer?
- Filligree 9y ago
  Depends on what you're using it for. A common use-case is cottages that run off the grid, which are only used in the summer half of the year anyway.
jacquesm 9y ago
But cold panels produce more power.

DamonHD 9y ago

PVGIS is an excellent tool and I have been using it for years!

shandor 9y ago

Thanks! That is quite surprising, and very encouraging. It seems that solar is a very good overall fit for even most of the world, and once the tech is good enough to be used in huge numbers the differences can probably be compensated with other, local power sources (like hydro in Scandinavia, which is huge there).

kodfodrasz 9y ago

Do I understand correctly that the wishful thinking value of 75% photovoltaic conversion efficiency is plotted in the diagram?

ju-st 9y ago
It means the conversion factor of yearly yield in kWh to installed PV in kWp. "Yearly sum of solar electricity generated by 1 kWp system". It's not about the physical PV efficiency.
- deleted 9y ago
  [deleted]
baking 9y ago
The 75% performance ratio represents system losses not module efficiency. So a system rated at 1kW(peak) which may be 5-6 square meters in size, and which is exposed to annual sunlight of 1200 kWh/m2 might only produce 900 kWh of usable power. So efficiency has to do with the rated power per surface area and the performance ratio reflects all the system electrical and environmental factors that reduce the amount of usable power below what would be expected based upon module ratings and annual sunlight exposure.

hanoz 9y ago

That diagram suggests Northern Sweden to Southern Europe is 50%, not 80%, which sounds more plausible.

philh 9y ago

> What people miss is that during the summer the sun is up all the time. (In the winter, not so much.) It sounds like these two effects should cancel each other out. Are you saying that people take winter into account but not summer?

Filligree 9y ago
Depends on what you're using it for. A common use-case is cottages that run off the grid, which are only used in the summer half of the year anyway.

jacquesm 9y ago

But cold panels produce more power.