# Calculating kWh

Hi,

How would I convert the irradiance given on a surface to kilowatt hours?

(Sorry for the dumb question :D)

Chris

not sure I understood your question, however:
100 kW/sqm -> take the area of the surface (10sqm) then you get 1'000 kW
then find the time interval (7 hours, may be) and kW h = 7'000

if you need to integrate during the day you need the average in kW for a
given time period and multiply for that....

···

----------
Christopher Kings-Lynne
Sent: Monday, January 31, 2005 10:56 AM

Hi,

How would I convert the irradiance given on a surface to kilowatt hours?

(Sorry for the dumb question :D)

Chris

_______________________________________________

___________________________________________________________________
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systems are scanned for acceptability of content and viruses.

I guess my question is 'in what units is the irradiance (-i) given in Radiance'?

Chris

Giulio Antonutto wrote:

···

not sure I understood your question, however:
100 kW/sqm -> take the area of the surface (10sqm) then you get 1'000 kW then find the time interval (7 hours, may be) and kW h = 7'000

if you need to integrate during the day you need the average in kW for a
given time period and multiply for that....

----------
Christopher Kings-Lynne
Sent: Monday, January 31, 2005 10:56 AM

Hi,

How would I convert the irradiance given on a surface to kilowatt hours?

(Sorry for the dumb question :D)

Chris

_______________________________________________

___________________________________________________________________
Electronic mail messages entering and leaving Arup business
systems are scanned for acceptability of content and viruses.

_______________________________________________

ooops....
well I believe that the irradiance Radiance gives you is referred only to
the visible spectrum....
unless you use some trick... (but I could be wrong...)
may be you wish to check some interesting works about the matter:

and

R. Compagnon, D. Raydan, Irradiance and illuminance distributions in urban
areas
Proceedings of PLEA 2000, Cambridge (UK), July 2000, editors: K. Steemers
and S. Yannas, James & James (Science Publishers) Ltd, London, 2000.

hope this is more usefull...
cheers
giulio

···

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Christopher Kings-Lynne
Sent: Monday, January 31, 2005 11:16 AM

I guess my question is 'in what units is the irradiance (-i) given in

Chris

Giulio Antonutto wrote:
> not sure I understood your question, however:
> 100 kW/sqm -> take the area of the surface (10sqm) then you get 1'000
kW
> then find the time interval (7 hours, may be) and kW h = 7'000
>
> if you need to integrate during the day you need the average in kW for a
> given time period and multiply for that....
> is it this your question?
>
>
>
>>----------
>>Christopher Kings-Lynne
>>Sent: Monday, January 31, 2005 10:56 AM
>>
>>Hi,
>>
>>How would I convert the irradiance given on a surface to kilowatt hours?
>>
>>(Sorry for the dumb question :D)
>>
>>Chris
>>
>>_______________________________________________
>>
>>
>>
>
> ___________________________________________________________________
> Electronic mail messages entering and leaving Arup business
> systems are scanned for acceptability of content and viruses.
>
> _______________________________________________