re: cooling of pv modules (was calculating windload...) SOLAR.KnowledgePublications.com

re: cooling of pv modules (was calculating windload...)
20 dec 2002
>a single layer of poly film with air on both sides has about 10% solar
>transmittance, of which about 8% is the fresnel loss...

an air (n1=1) polyethylene (n2=1.5) interface has ((n2-n1)/(n2+n1))^2 = 0.04,
ie a 4% loss. water (1.33) and poly have ((1.33-1.5)/(1.33+1.5))^2 = 0.0036,
ie a 0.36% loss. poly and glass (1.5 for the pv face?) would have no loss. 

the panel might only see something like a 4% loss for the air-to-top film
interface plus a 1% loss for the two water-poly interfaces plus a 4%
transmission loss for the two film layers, a total of 9%... 

nick