Dimensionning solar panels

[beerbaron]

Hi, I'm trying to charge batteries with solar cells. My problem is dimensioning the solar panels correctly.

From what I understand most solar pannel are about 12% efficient. So at 12:00 and around (100 000 lux) I could expect 120 W/square meter (sun is 1000 W / meter).

My question first question is, is the power transmitted linear, let's say I have only 50 000 lux, will it mean I will have 60W?

My second question is, 12% for most solar panels seems like a pretty gross rule of thumb. Is there some technologies that have more or less efficiency?

Best regards
BeerBaron

 

[Marmite]

Under real conditions the irradiance of the sun is between 350 and 650W/sqm. The 1000W figure comes from standard test conditions used to compare cells. The actual figure depends on a lot of things such as season, time of day, angle of incidence, weather etc. The efficiency of most cells is around 15%. The most efficient cells are around 25%. To extract most energy in the northern hemisphere the panels should face South inclined at an angle close to the latitude of the site.
Regards
Marmite

 

[itsmoked]

and track the sun. You must also use a charge controller or the panels will destroy the batteries.

Keith Cress
Flamin Systems, Inc.-

http://www.flaminsystems.com