Do-Yourself-Solar Technologies

The do-yourself-solar technologies and hands-on solar seminars have been the trademarks we have become known by. On this page we will highlight recent workshop and seminar activities, with photos and special quotes from facilitators and participants. We will also focus at times, on past reports from our work the world over, as well as promoting our up-coming workshops and activities related to our focus. Products and related articles will also be promoted here. 

--------------------------------------------------------

65W PV supplies-

and Step by Step procedure for DADS/MESEA/SEADS -        

do-yourself-solar, hands-on assembly workshop!

Winter 2014 update  -  Maine Solar Energy Assoc. / dadsolar.com   

MESEA  -  65W  PV  Assembly Process  -  This 'hand-out' is updated for each workshop

We start our PV assembly process by acquiring the necessary component parts and supplies:

Solar cells- .5V poly-crystalline PV cells, off-spec., (150mm x 80mm), 36 cells per module, 18V, no load.  (originally from Evergreen Solar, Marlboro, MA, these cells are rated to be Approx: 1.8W @ 3.6 A,  other suppliers available)                            (Volts x Amps = Watts)                                                                               

Liquid silicon – Dow – DC 184 – 8.8lb – Sylgard – 2 part Kit, (Essex-Brownell, [Superior-Essex], Ft. Wayne, IN)   

Tempered glass – 26” x 32”, clear, 3/16” thick, - for 60W module (In some areas double-strength window glass, and other size configurations are used, when tempered glass is not available locally).                                                        

Aluminum frames – For 26” x 32” glass, (or other configuration), Arthaus, Nielsen #22, (or #117), with hardware for corners. (Other possible options, with local restrictions).                                

Backing sheets – White, #20 lb bond paper, (sized larger than glass), for capillary action; and clear vinyl (PVC)  roll stock for finished backing, (sized larger than glass size).                        

Junction box - Handmade, ½” cut caulk tube, to secure wiring to module, with 100% silicone caulk. (UL listed, Multi-Contact, PV – JB/K2, 10A rated and by-pass diode, if desired).                 

Misc. supplies -  Solder, ribbon and tools – Kester brand, lead free, rosin core solder; Weller brand, 40W soldering iron (AC or DC, for local requirement); tabbing (.05mm x 1.5mm wide) and buss (.2mm to .5mm x 8mm wide) tinned-copper ribbon; assorted tools, wire stripper, screwdrivers, scissors, razor knife, clear -100% silicone caulk and gun, 3mil plastic sheet, level table and flexible ½” styrofoam board (base for encapsulation), masking tape and red and blue 16AWG wire.

-----------------------------------------------------------------------------------

We continue with our first step: choosing and soldering PV cells. We check cells from supplier for integrity (Grade B cells may have cosmetic blemishes). After selecting 36 – 40 acceptable cells, for 65W module (some may break during soldering), we set up strings (4 strings of 9 cells or 3 strings of 12), on straight edge for soldering. With tabbed cells (full tabbing ribbon on front, neg. side of cell), the cells are laid on straight edge and tabbing is soldered from front (neg. side), of one cell, to the back (pos. side) of the next cell, (this is done with a maximum of 1/8” space between each cell in the string, we must fit the glass size area), for a series connection, (adding the voltage of each cell). Some cells will need tabbing ribbon soldered on to the front of cells, the ribbons should not touch the next cells ribbon, to avoid a short circuit. After 4 strings of 9 cells (or other configuration), are soldered, each string is checked with digital multi-meter, for minimum no-load output, (4.5V to 5.2V, for 9 cell string), in full sun. (Each string should be about equal, depending on the solar insolation at the moment). An option to use 3 strings of 12 cells  (or 11 in cooler northern climates), making a 36 or 33 cell 65W module, when there is a difficulty acquiring tempered glass, will require a 21" x 41", double thickness window glass. (The 11 or 12 cell strings have 6V to 7.5V output, with various sunlight.)

Our second step: encapsulation, with the Dow Sylgard 184, liquid silicon kit. On our level work table, we lay out a sheet of 3 mil plastic (black garbage bag), on top of styrofoam board for work base. Then the vinyl backing sheet and the #20 lb paper sheet next, (these should be larger than the required glass size). Use a pencil to mark the paper with the glass perimeter, so the PV strings can be added on the paper in the most economical manner, (with the least space between each string and centered on glass size, marked on paper). The strings should be laid on the paper for series connection, (each string end will alternate, pos. and neg.), for adding the volts of each string, to reach our 18V minimum, no-load output. Next, the buss ribbon is cut for the series connections at the string ends, (the center strings, with 4 string configuration, will be the ends for the junction box, on the back). The tabbing ribbon is soldered to the buss ribbon in series, and the pos. and neg. ends of the full 36 cells (buss ribbon ends), are slipped through the paper and vinyl sheets (center of module top), after two small slices are made with a razor knife. The ends are then bent flat and we re-check the string layout for encapsulation. We will add two applications (approx. 7 – 8 fl. oz., or 200ml each), to fully cover the strings and cells as well as the paper. The first Sylgard application is mixed and poured onto the strings, making sure the spaces between the strings are covered. Next, the final application of Sylgard is poured onto the strings and spread gently with plastic mixing cup or fingers. After we have made sure that all the cells are fully covered with Sylgard, we allow the liquid to settle onto the level module for ten minutes. Then, after checking the layout for the last time, we gently place the glass onto the strings, in the exact perimeter drawn earlier on the paper. A piece of cardboard for protection and a weight (30 lb – 40 lb), is applied onto the glass, and we are finished with this step. (The Sylgard will be absorbed through capillary action, to the back of each cell).

Our final step: final wiring and framing, will be accomplished after the Sylgard has “set-up”, which may be two to three days, depending on local environmental conditions. We may have one ready for this step, which has been pre-assembled and allowed to “cure”. The cured module is turned over and the glass edge is used as a guide, to cut back the vinyl and paper with a razor knife. We check the full module output, in the full sun (18V @ 3.6A = 64.8W), usually above the 65W rating. Our caulking tube / junction box is attached to the back of the module (using the 100% silicone caulk to fill the  ½” of cut tube, fully covering and separating the soldered ribbon and wires), after soldering the red (pos) wire and blue (neg) wire (16AWG), for the final connection. These wires may be 12” or 14” for connecting modules to each other in an array. The aluminum framing (Neilsen #22 or other available framing) is installed on the module, using the 100% silicone caulk on the rear and front sides of the module, to seal the module and make a secure frame job. The caulk is allowed to sit for a few hours, while setting up. Solder may be applied at the corners of the frame and a ground screw hole drilled for the earth ground required. After the caulk dries, the excess may be sliced away from the front of the module. Glass cleaner is used for the final cleaning. Another test with multi-meter should be accomplished. We recommend these “handmade” modules be used for off-grid homes and applications. Thank you!

Please refer to Practical Photovoltaics, by Dr. Richard Komp, for detailed explanations of the process allowing the solar illumination (photons), to activate / excite the electrons in the solar PV cells.

Check the websites – www.mainesolar.org and www.dadsolar.com for photos and stories of Int'l. and domestic workshops.

--------------------------------------------------

From pictures on Home page 1, of cell phone charger assembly ...

MESEA Solar Cell Phone Charger …

materials and assembly procedures … Spring 2014

Materials : Solar PV Cells, 4 (to cover breakage) - Si poly-crystalline, 150 x 80 mm (3” x 6”), cut into ¼ size cells (40 x 75 mm), 12 pieces (12 x .5V = 6 V), ¼ cell = .9 A.                                              

Si Caulk (100%), One tube, (GE Silicone1) clear Si caulk.                                                                   

One 9” x 12” picture frame, ($1.00 store) includes frame, glass & backing board.                         

Solder, ribbon, wire and tools, Kester brand, elec. solder – rosin core; Weller brand 40W soldering iron; tabbing ribbon (.05mm x 1.5 mm thick) tinned copper; wire stripper; scissors; razor knife; caulk gun; elec. tape; red & blue insulated 16 AWG wire; diamond cutting wheel (Dremel type); stiff cardboard, cut for scoring the PV cells (40, 75mm); 2 - 1/8” thick plexiglass pcs (3” x 6”) for breaking the scored PV cells;  an electrical  multi-meter for testing the voltage and amperage of each string.

Procedure : Cut the full size (3” x 6”) Si cells into ¼ pieces (40 x 75mm), using the cardboard guide and the diamond cutting wheel, to score the cells. You may need to remove the ribbon already soldered to the cell, and cut one direction at a time. The important aspect is to keep the soldering spot in the same position for each cell. (middle on front [neg] side, with one pad on the back [pos] side). This is to align the cells into equal size ‘strings’ (4 cells x 3 strings = 12 cells), some may break unevenly during scoring or breaking along the score line. (You may also use cells already broken, making sure the soldering spots are aligned correctly). After scoring the cell in one direction with the guide and diamond cutting wheel (5 or 6 times across should be enough, your pressure will determine this), then align the score mark on the edge of and on top of a piece of plexi. Then place the other plexi piece on top of the scored cell and using the edge of the table, allow the top plexi to break the cell along the scored mark. This may take a few times to get correctly, and why we have extra PV cells. Next, score and break the other measure, using the cardboard guide, the diamond cutting wheel and plexi pieces. We do need 12 pieces of cut Si PV cells, each cell is .5V, the size determines the amperage (1/4 cell = .9 A). The finished cell charger is 6V x .9A =5W, rated.         

Next we will solder the cells in a series connection, Neg (front side) to the Pos (back side), which adds the voltage together (a parallel connection, pos to pos, and neg to neg, adds the amperage), using the tabbing ribbon, leaving only 1/16 “ between each cell. Each string will have 4 - ¼ cells, 3 strings x 4 cells = 12 cut cells in all. The ribbon is soldered to the front solder strip with enough extra ribbon to meet the solder pad on the back of the next cut cell in the string. Heat the solder pad or strip with the iron and apply a small bit of solder, spreading it flat. Then hold the ribbon in place and slowly pull the iron along the ribbon and watch the heat transfer to the solder on the strip, melting, and as you remove the iron the ribbon is attached. (You will notice that the ribbon does heat up as you apply the iron, try not to over-heat the strip or pad). Repeat for each cell in each string. We will have 3 strings, each with a ribbon from both ends (one neg [front] and one pos [back]), for our final soldering with all 12 cells in a series connection. We will test the output in full sun (if available) with the multi-meter. Each string should be 2V and .9A, (rated), so we are checking that each string has the same output.

The picture frame is opened from the rear and the backing cardboard removed, marking the space for the 3 strings so the frame will not hit or interfere, and there will be room for a 16AWG wire to fit inside the frame edge. The 3 strings of 4 – ¼ cells are placed onto the inside of the backing board, and a bead of 100% Si caulk is applied across the back of each cut cell, and the full string is then ‘gently’ placed in position and pressed down ‘gently’ onto the backing board. (If there is breakage at this point, we can remove and replace a cell if required). After the 3 strings are placed (each string has pos and neg ends alternating with the next string end, for series connection with solder and ribbon between each string), and caulk applied, the ribbon is cut to connect each string to the next on both ends (so, neg to pos, and pos to neg) and a series connection is accomplished with the solder and iron. A strip of cardboard ¼ “ wide is inserted between each string as well as on all 4 sides of the cells, and caulk added to secure the strips to the backing board. This will allow the glass to touch the strips, so the cells will not be in contact with the glass. Make sure the strips are high enough to accomplish this. Before the final wiring and closure, we will test the entire PV module with the multi-meter, there should be approx. 6V and the .9A for the rated module output.

The framing is checked for a tight fit, with no interference from the glass, cells and frame. The two ribbon ends (one pos and one neg), will have a coordinated 16 AWG wire (red for pos, and blue for neg), soldered to the ribbon and one wire will be placed along the edge of the frame, inside, and come to the other end of the module (so both wires will be on the same end). The two wires will then be put through a hole in the backing board and caulk applied in the hole as well as along the wire inside the frame edge, to hold that in place. The inside perimeter of the frame should be caulked before the backing board is sealed with the pieces designed for closure of the backing board. The PV is thicker than a picture or certificate would be, so there will be a tight fit. The elec. tape (or masking / duct tape) can be applied for extra secure fitting and the multi-meter used again for a final test. As the red and blue wires are both coming out through the backing board, they should have an equal length, approx. 12”. The wires will be matched to a plug from the required phone charger (each phone may have a different plug) and the ph can be charged from a window in the sun or outside facing the sun. We have found that most phones may be charged with this PV module, except an apple I-phone that may require a DC charger plug from apple …

Please see the Home page for picture of this process, thanks !

Participants at PV assembly workshop, September, 2009, Brooklyn, NY. Selecting cells and soldering strings for 65W PV module.

Drawing for solar thermal installation, showing detail of copper tubing inside insulated box, June - 2008.

Homemade heat exchanger  ready for attachment to tank at Harrington, Maine, solar thermal workshop, July - 2008.

Links and Activities - DADS, Inc., a new, educational non-profit Corp. in Maine, 2011.

We are pleased to present the On-going, Hands-on SOLAR SEMINAR series

With our Sister Organizations - Maine Solar Energy Association - www.mainesolar.org ,

Solar Energy Awareness & Demonstration Seminars. Inc.,- www.seadsoftruth.webs.com ,  and Skyheat Associates !

Please check the CONTACT US page for updated contact and workshop information.

Drawing for "thermosiphon" hot air collector, to be attached on south wall of dwelling. From Maine Solar Energy Association, Maine Solar Primer, 2nd edition.
* Link for the complete Maine Solar Primer, is on the Home page.

Updated Photo of this solar thermal installation on Contact Us page.