Hamsa

9 responses to “Hamsa”

1. 

   nhr

   Apr 14, 2009 at 5:17 am

   > what is the hand of Fatima resting on?

   Thin-film photovoltaic laminates, perchance ?

   Reply
2. 

   In Memoriam: jerryfi_99

   Apr 14, 2009 at 8:42 am

   A really big Lava Lamp?-)

   Solar concentrator, maybe for a pool heater?

   Reply
3. 

   Todd Huffman

   Apr 14, 2009 at 10:46 am

   Crazy coincidence! I just posted one too!

   http://www.flickr.com/photos/oddwick/3440571073/

   A few days ago we were exploring ancient Buddhist caves, and there are lots of the ‘hand’ carvings.

   Reply
4. 

   TomiTapio

   Apr 14, 2009 at 12:29 pm

   Definitely something to do with sunlight, that surface.

   Reply
5. 

   jurvetson

   Apr 14, 2009 at 6:02 pm

   Yes! and Bingo nhr, and within an hour of the post no less.

   It is a Polymer-fullerene solar cell, a low-cost organic thin-film spread on plastic in a high-speed roll-to-roll press:

   

   They use the equipment that Polaroid used to use for making film. It is called Konarka Power Plastic

   

   They are lightweight and can be embedded in other products, like handbags to recharge devices, or awnings and umbrellas at cafes, or on top of a chicken coop or greenhouse. They also have a transparent bi-facial version that is laminated to windows to generate electricity as a window tinting

   

   The efficiency is lower than a silicon cell, but the cost is 10x lower, and the installed cost lower still. It also allows for conformable shapes (your device cases can harvest free energy) and even to be woven as a fabric (solar camo).

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6. 

   P^2 – Paul

   Apr 14, 2009 at 7:28 pm

   Cool. I hope they can get the efficiency up – it seems like this would make great stuff to embed in roofing material.

   Let’s see: My house has almost perfect southern exposure, with a roof the same angle as my latitude. Given the datasheets on the Konarka site, if I cover all 45 square metres of the roof half facing south, I can expect a peak output of of 750 watts. According to NREL’s insolation maps (http://rredc.nrel.gov/solar/old_data/nsrdb/redbook/atlas/ ) I’ll get an an average of 90 kWh/month out of this, or about 10% of what I actually use. OK, so maybe this isn’t the best application for it, here in the great white north. It does seem better suited to the applications you mention.

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7. 

   complexify.

   Apr 14, 2009 at 10:06 pm

   "They use the equipment that Polaroid used to use for making film."

   That’s fantastic. I found a brief article about the factory conversion here.

   I hope the creative, productive repurposing of obsolescing capital goods and skilled labor becomes the "swords to ploughshares" of our time.

   Reply
8. 

   msamaclean ©

   Apr 14, 2009 at 11:14 pm

   Very interesting & effective shot!
   I have been following Konarka & it’s expanding applications for this film.

   Reply
9. 

   rocketmavericks

   Apr 15, 2009 at 4:13 am

   Very interesting thin film coating application. I think I did the control system on this line for Polaroid back when it was a film coating line. The control system was a challenge, because it consisted of a biaxially- extruded film production line that then was fed into a coating system.
   It runs like an animal and is pretty interesting to see. They cast a polyester on a chill roll that rotates with a thinkness of about 2-3 inches. As the polymer sets at the bottom of the roll, it is pulled away from the chill roll by tension controlled by motor controllers, with a heating element right at the separation point. The polyer heats just to the glass transition temperature, and necks down to about 3/4 of an inch, where its sides are grabbed by mechanical clips. Here there is an arrangement of horizontally placed and controlled heating zones, that control the heat, and the plastic is streatched to about 3-5 mils in thickness horizontally, and espands from about 3 ft in cross-section, to about 30 feet. The interesting part is that all of this is running at about 60 MPH. SCREAMING fast. The bi-axially extruded film then goes into a coating system. We used radioisotopic (Am-241?) sensors to gauge the film thickness and consistency scanning back and forth across the film sheet, feeding back to the motor controllers, and longitudinal streatch and axis stretch heating units to control the polmer stretch, and then measured again after the coater to measure the film coatings. It was one of the most challenging control system I ever designed and built. Don;t get those kinds of projects anymore. Explains why I get so bored programming databases for the web, and hacking iPhones to stream video. No wonder I switched to rockets.Sigh…… The good old days of technology development in the 80’s in the valley when the applications had some real challenges. Nothing like a nitroglycerin reactor control system I had to do, but that is another more explosive story…

   Nice to see Polaroid found another use for the production line. I figured it got unbolted with everything else in the country and sold off to China to copy and line the pockets of Wall Street and the corporate greed of the last 20 years.

   Reply