Re: [Phys-L] solar constant

[John Denker <jsd@av8n.com>]

On 05/21/2014 07:04 AM, Anthony Lapinski wrote:
> 1. How can I find the approximate value on a given day at a given location
> (latitude)? Is there some formula or way to estimate? I realize this might
> not be easy.

It's messy, but maybe doable, depending on where you live.
Start by finding the elevation of the sun:
  http://en.wikipedia.org/wiki/Position_of_the_Sun

Then to a first approximation, the power per unit area of
real-estate scales like the cosine of the angle.  This is
just geometry plus conservation of energy.

The biggest remaining variable is weather.  Relatively little
energy is absorbed by clear air ... but clouds can block
nearly 100% of the energy.

So it very much depends on whether you live in Yuma or
Seattle.