[RE-wrenches] Low light panel

[Darryl Thayer]

Thanks Peter, I was trying to figure out how to translate from lumens, good job
Darryl




________________________________
From: Peter Parrish <peter.parrish at calsolareng.com>
To: RE-wrenches <re-wrenches at lists.re-wrenches.org>
Sent: Thu, February 3, 2011 5:40:44 PM
Subject: Re: [RE-wrenches] Low light panel

This is a pretty good example of how obscure the various "lighting"
variables are for even solar pros. 

I won't go into the gory details (and they are details of some depth, trust
me). So let's take the following shortcut.

A decent CFL puts out 60 lumens per watt of power consumed. So, in theory,
one could get 60 lumens from a tiny CFL drawing 1 watt of electrical power.

One watt of electrical power going into the CFL and 60 lumens out.

If you illuminated the PV module with those 60 lumens and it produced 0.7 A
@ 14 volts, that would be 20 watts of electricity.

Lo and behold! You got 20 Watts out from 1 Watt in.

You have just violated the "conservation of energy" by a factor of 20X.

- Peter



                                                    
Peter T. Parrish, Ph.D., President
California Solar Engineering, Inc.
820 Cynthia Ave., Los Angeles, CA 90065
CA Lic. 854779, NABCEP Cert. 031806-26
peter.parrish at calsolareng.com  
Ph 323-258-8883, Mobile 323-839-6108, Fax 323-258-8885


-----Original Message-----
From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Carl Adams
Sent: Thursday, February 03, 2011 1:19 PM
To: RE-wrenches at lists.re-wrenches.org
Subject: [RE-wrenches] Low light panel

Hello Wrenches,

I'm looking for a panel which will provide
0.7A at 12-20V
with only a 60 lumen light source for the irradiance source

With REgards
Carl  Adams
SunRock Solar LLC
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