[DB]

Hey, that's from the paper I posted a link to sometime ago...

That 19% is only an average for the whole earth including typical cloud cover, water vapor, etc. Light also reflects off the atmosphere and clouds sending it out to space.

On a clear day with no clouds and low water vapor the amount of radiant energy reaching the ground has to be much higher.

It is widely accepted that the sun provides about 1380 watts per square meter of radiation just above the atmosphere. It takes 1000 watts per square meter for a 13% efficient solar cell to produce 130 watts per square meter. This is what they do on a clear day not too far from the equator. Therefore about 72% of the suns radiation has to penetrate the atmosphere and land on the solar cell's surface to produce this much electricity. Significantly higher than the 49% average world wide

[Boot Hill]

"It takes 1000 watts per square meter for a 13% efficient solar cell to produce 130 watts per square meter."

LOL, that 1,000 watts spec the manufacturers like to cite is the game we call "specs-manship"! There is no place on earth that gets that much solar radiation. If you read the fine print on their specs you'll find that even they will admit that a more realistic number is 800 W/m². But my comments are a bit off-topic.

Maybe after a nights sleep ableChair will have had a chance to think over what so many posters have been trying to explain to him and hopefully it will sink in. But other than that, I don't know what else to offer. I feel like I've been beating my head against a brick wall!

--Boot Hill