[RE-wrenches] Bifacial modules

[Keith Cronin]

Thanks everyone for the feedback!

Thinking that the manu's can space cells accordingly on the surface of the glass and create whatever % light the end user wants to seep through.

The % of light must slide between 5-15%, depending on manu's specs. Architecture can meet solar and increase the applicability of the products.

Perhaps someday, they can make the cells see-through (or almost), like glass.......? Now that opens up possibilities! 
 
Aloha,


Keith


________________________________
From: Phil Undercuffler <solarphil at gmail.com>
To: Keith Cronin <electrichi01 at yahoo.com>; RE-wrenches <re-wrenches at lists.re-wrenches.org>
Cc: Bill Brooks <billbrooks7 at yahoo.com>
Sent: Wednesday, November 2, 2011 9:18 AM
Subject: Re: [RE-wrenches] Bifacial modules


We've got an array of Silicon Energy modules "out back," and in the interests of scientific discovery and procrastinating from what I really am supposed to be doing, Kelly, Seth and I just ran a few experiments to see if we can quantify the amount of irradiation that makes it through the array.

Using a Kyocera module as our reference, we measured ISC with the module in the plane of the array, then moved the module to the same orientation but approximately 12 feet behind and in the shade of the SE array, and again measured ISC.  Sun conditions were light wispy clouds, guesstimated 800 W/M2 (pretty darned good for Arlington WA this time o' year), 10:30 local time.  We measured 5.9A ISC in front of the array, and 610 milliamps when in the shade the array, leading us to say that just over 10% of the available sun will make it to your orchids.

It should be noted that there is a opaque backing behind each SE cell, so the only light that makes it through is through the intercell gaps.  I've used Sanyo doubles before, and in those modules the cells are slightly translucent, so the sun is somewhat visible through the body of the cell itself as well -- sort of like looking through very dark sunglasses.  In either case, the illumination on objects behind the array is a dappled, dynamic light.  As Bill says, it's pretty cool from an aesthetic point of view.  My personal .02 is that there is no finer place to put an array than a shade structure using clear modules.  It keeps everything off the roof, gives shade and makes for a premium installation option.

Phil
-----------
"When we learn how to store electricity, we will cease being apes ourselves; until then we are tailless orangutans. You see, we should utilize natural forces and thus get all of our power. Sunshine is a form of energy, and the winds and the tides are manifestations of energy.  Do we use them? Oh, no! We burn up wood and coal, as renters burn up the front fence for fuel. We live like squatters, not as if we owned the property.  

There must surely come a time when heat and power will be stored in unlimited quantities in every community, all gathered by natural forces."
-- Thomas Edison --



On Tue, Nov 1, 2011 at 7:48 PM, Keith Cronin <electrichi01 at yahoo.com> wrote:

Bill
>
>
>Appreciate the feedback. One of the questions that I'm seeking to determine- how much light will filter through the spaces between the cells to the surface below?
>
>
>Lets say for someone that wants to grow orchids- they need low light, as an example.
>
>
>Wondering how much light is diffused through the panels to be able to do things like grow orchids and or have filtered light to work?
>
>
>As an example: Do any of you have irradiance measurements on any carports that have done bifacials and determined how many watts sq m are below?
>
>
>Keith
>
>
>________________________________
>From: Bill Brooks <billbrooks7 at yahoo.com>
>To: 'Keith Cronin' <electrichi01 at yahoo.com>; 'RE-wrenches' <re-wrenches at lists.re-wrenches.org>
>Sent: Tuesday, November 1, 2011 11:44 AM
>Subject: RE: [RE-wrenches] Bifacial modules
>
>
>
>Keith,
> 
>This is easy to test. Simple take an irradiance sensor, turn it upside-down and test the irradiance on the bottom surface of any PV array. It will vary greatly based on exposure to reflected light and so on, but it will rarely be above 100 W/m^2. 10% improvement is an absolute maximum for any bifacial technology, and that is on the high side. Any claims above 10% are ignoring the physics of sunlight, reflectance of typical materials, and PV.
> 
>Nothing wrong with bi-facials. They are beautiful to look at. I would buy them based on aesthetics, not on performance.
> 
>Bill.
> 
>From:re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Keith Cronin
>Sent: Tuesday, November 01, 2011 1:04 PM
>To: RE-Wrenches
>Subject: [RE-wrenches] Bifacial modules
> 
>Hi
> 
>Was wondering if any of you have installed bifacial modules and know what the % of light that comes through to a surface below the modules?
> 
>Looking for a canopy type of installation/ application and wondered if you have any #'s?
> 
>Thank you~
> 
>Aloha,
>Keith
>
>
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