ESPM

Since solar cells come in a variety of shapes and sizes, it is not possible to give exact dimensions for the particular panel you will build. Your panel dimensions will depend on what size cells you are going to use, how much power it will generate, and where it is going to be situated. These 

I will show you how a panel is designed and constructed. This will show you how to make your own calculations based on the materials you have and your power demands. 

The first design consideration is to determine what the power needs of the electrolyzer will be. 

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Larrosa, M. Garcia-Conesa, M.T. Espm, J.C. Tomas-Barberan, F.A. 2010. Ellagitannins, ellagic acid and vascular health. Mol. Asp. Med. 31 513-539. 

Our renewable energy power supply was two ESPMs that output about four volts at 20 amps (open circuit voltage, short circuit current). 

When the tank is filled to the preset maximum pressure, the blue High wire is connected via the switch to the black Common wire. This turns the electrolyzer off. When the pressure falls to a certain preset low pressure the red Low wire is connected to the black Common wire and the electrolyzer is turned on to produce more gas. If there is no power available when the pressure is at the Low preset level, such as when ESPMs or other intermittent energy sources are used, the circuitry will set and be ready to go when power is available - when the sun rises in the morning, or the wind blows again. 

The photovoltaic power source can be any commercial BSPM (Battery Specific Photovoltaic Module), or can be an ESPM (Electrolyzer Specific Photovoltaic Module). The electrolyzer can either be a PEM (Proton Exchange Membrane) or an alkaline type. 

This is an important consideration. Using larger area cells in an ESPM allows you to use fewer cells in each string, which saves time and work when constructing panels, as there are fewer tab and bus connects to solder. 

ESPMs (Electrolyzer Specific Photovoltaic Modules) are uniquely designed to match the power requirements of electrolyzer systems. This makes them more energy efficient and economical for their intended use. 

Whereas BSPMs output higher voltages and lower currents, ESPMs output higher current and lower voltages. 

For ESPMs, a. 005 thick tab ribbon is sufficient to connect the individual cells to the bus ribbon, but the bus ribbon needs to be larger to accommodate the larger current carried. For the panels described here, a 20 amp capacity conductor is needed for the bus wire. Most suppliers of cells do not have bus ribbon in the thicknesses required. Enquire and see what is available. 

For an ESPM as discussed in this book, use at least a. 005 thick ribbon for the cell connects. The bus ribbon needs to be able to carry the current of this ESPM, for instance. 010" thick, at /s" wide or a. 020" thick at /32" wide. 

Two ESPMs were constructed for this project. The design was based on materials that were on hand, so the finished products are not optimal, but were relatively inexpensive. For each panel back, I used a 28" x 30" sheet of rigid aluminum metal that was a little less than Vie" thick. I purchased a piece of fiberboard and cut it to 28" x 30" (the same dimensions as planned for the finished panels) so that I could use it as a peel, a soldering platform, and layout grid for the cells, tab and bus ribbon positions for the panels. I used 4 pieces of V4 x 1" aluminum bar stock for a... 

For the ESPMs I made, I used precut 28"x 30" sheet aluminum that was about Vie" of an thick. For the side bar/framing material I used 1" by /4" aluminum bar stock cut into four 28" pieces for each panel. For the covers I used 3/32" thick Plexiglass that was cut at the hardware store to 28"x 30". When you purchase a cut Plexiglass sheet, it usually has a thin film on either side to protect the surface from scratches. Leave this film on while you drill and until you are ready to finally assemble the panel. It will protect the Plexiglass from scratches during construction. 

Connecting block configuration for two ESPMs connected in series. 

If you wish to purchase ESPMs rather than build your own, be ready for some sticker shock. While it is inexpensive to build these panels, it is not inexpensive to buy them. The reason is that the photovoltaic industry has not yet caught up with the idea of the coming hydrogen economy. This is no surprise, since many PV companies are owned by large oil companies, and for a variety of reasons they are not interested in promoting small scale hydrogen production. 

The power cord coming from the power supply should be a 12 gauge, or preferably a 10 gauge zip or other wire if you are using ESPMs. Other wire can be used, as long as it is rated for this use. 

A bank of parallel connected electrolyzers requires ESPMs that can deliver lower voltage and higher currents. For instance, to power 3 electrolyzers at 4 volts and 20 amps, you would have... 

Operating with ESPMs that produce 4 volts at 20 amps per panel, would require three panels connected in parallel to produce the 60... 

Cerda, B., Tomas-Barberan, F.A., and Espm, J.C., Metabolism of chemopreventive and antioxidant ella-gitannins from strawberries, raspberries, walnuts and oak-aged wines in humans Identification of biomarkers and individual variability, J. Agric. Food Chem., 53, 227-235, 2005. 

Cerda, B., Espm, J.C., Parra, A., Martinez, P., and Tomas-Barberan, F. A., The potent in vitro antioxidant ellagitannins from pomegranate juice are metabolized into bioavailable but poor antioxidant hydroxy-6//-dibenzopyran-6-one derivatives by the colonic microflora of healthy humans, Eur. J. Nutr., 43, 205-220, 2004. 

Segura D, Cruz T, Espm G (2003) Encystment and alkylresorcinol production by Azotobacter vinelandii strains impaired in poly-beta-hydroxybutyrate synthesis. Arch Microbiol 179 437-443... 

Espm JC, Garcia-Conesa MT, Tomas-Barberan FA (2007) Nutraceuticals facts and fiction. Phytochemistry 68 2986—3008... 

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