DIY Solar Panels (2017)
Section #2 A) Hand-Crafted Solar Panel, Just Before You Go “WIP”
Just some background so I am not humming the Star Spangled Banner while you hum My Country Tis of Thee. I am trying to fill in every blank that left me scratching my head when I first started because I couldn’t find answers anywhere.
Tools of the Trade: There are a few tools one must have in order to handcraft solar panels. The good news is that the cost associated with “gearing-up” is not extreme; in fact, I would have to say it is very inexpensive to enter this trade.
ü Soldering gun or iron - minimum of 45-watt, with the wide tip. A word to the wise on equipment such as this, stick with brand names with proven reliability. My preference is the Weller Soldering Gun 8100-B, 100-watt but there are several models available from this trusted brand.
ü Spare soldering tips - at least one pair on hand at all times. You should also have a collection of tools needed to keep the soldering tools clean to include a sponge, wire mesh dipping tray, and a stand to rest the soldering gun/iron on during use.
ü Rosin core solder - iron-free-99.3% Tin, .07% Copper. It doesn’t need to be this exact mix, but melting points should be approximately 350° F.
ü Flux Pen - Kester brand, #186-needed to bond the rosin core solder to the surfaces being joined. Any brand pen will suffice.
ü Probes and Pokers - (Pictured on the next page) tools with which to hold down delicate tabbing wire or to move parts without having to use potentially oily fingers (which might compromise the solder). Also, when using the solder gun the temperatures can exceed 400° F, capable of inflicting serious burns to flesh, so the use of probes help keep flesh off the hot parts.
ü Weights - to aid in positioning of solar cells and tabbing wire prior to soldering because things tend to move when contacted by the solder tip. Sockets from a tool kit work well but virtually any dense, heavy and appropriately sized object. It is a good idea to apply a soft non-slip coating to the bottom of the metal sockets, preferably something that will provide protection against scratching of the solar cells like a rubber plumbing gasket material. Simply cut out a piece of rubber and attach with two-sided tape (so you can tear it off if you need to use the socket). Always use great care when setting the weights down onto a solar cell! Gently lower the weight onto the target and set it down ever so lightly.
ü Safety Glasses - to protect eyes against foreign objects.
ü Wire Cutting - you can use small scissors or small wire cutting tools.
ü Magnifying Glass - for close inspection of solder joints, inspecting solar cells for cracks, or if you have questionable eyesight, a hat-like device with a magnification lens that can be rotated down for hands-free magnification.
ü Measuring Tape - or ruler, yardstick, or flexible-soft measuring tape. A three foot yardstick is useful.
ü Yardstick - a thick wood model is preferable because you will use it to draw straight lines on the substrate (the surface that you mount the strings of solar cells in the final stages of assembly). Straight lines are essential in solar panel construction whether physically drawing out the solar cell pair placement on your work surface, or tracing the outline prior to cutting your Plexiglas covers.
ü T-Square - typically a tool used in the drafting trade, this is a valuable tool for ensuring with 100% certainty your lines are at true angles such as when tracing your substrate cutout pattern. Throughout your design and construction phases accuracy is absolutely critical! Corners have to be 90° or things simply will not fit making it look amateurish and difficult to weather seal. I can live with amateurish but unfortunately the life of the solar panel depends on a moisture free environment. I use the same T-square I bought in 1982 for a high school drafting class in virtually every project I have ever done as an adult.
ü Combination Square - because it is such an accurate tool for giving you the PERFECTLY sized template for the tabbing wire strips you will be cutting, or for drawing outlines on a smaller scale. An excellent all-around measuring tool with leveling capabilities which you will need later.
We are DIY people, otherwise you wouldn’t be reading this, nor would I be writing it. There is just something about that feeling of pride, of fist-pumping, back-slapping, you just pried your dog from the jaws of an alligator type primal feeling of victory when the _ _ _ _ _ _ (fill in the blanks) actually works!!! Like that feeling you get when you plug your own flat tire after you had priced it at the local tire retailer at $120 installed, with a patch kit that cost under $5. The examples go on and on, and I bet each of you has a great success story to share. I am confident you know the feelings of joy I describe.
The funny thing is that in all that back-slapping we tend to gloss over the more unpleasant obstacles we overcame to finally achieve success. The best way to avoid a negative outcome while handcrafting a solar panel is to maintain a clean, organized, and clutter-free work area. No, I didn’t just land on this planet from Mars. I live here as well, and have the same space restrictions as most. Unless you are fabulously wealthy, and have a few extra hobby rooms or a seven-car garage, you will have to carve out space perhaps using mining equipment and explosives. I will give you the bullet points, and you find what works for you. The following is a list of what is involved in the identification of a suitable area to ply your trade. You will need…
ü Sturdy Surface - you won’t be pounding horseshoes on an anvil but you need a surface that will be level, and steady. You will be performing delicate work requiring a steady hand, so a wobbly table won’t work. It can be a plank of wood laid across a dozen cinder blocks if that is all you have, just make it steady enough to lean on without resulting in vibration.
ü Project Surface - the surface that you will be soldering on, staging your pre-cut tabbing wire, recently soldered single and paired solar cells, soldering support sponge, and poking/holding tools for the duration of your project. It should be sturdy enough to be carried as you transition from active work, to securing your WIP between sessions. Glass is ideal for soldering on because it dissipates heat efficiently thus reducing the occurrence of heat related solar cell fractures. Ceramic is also good such as the type used in decorative tile walkways or industrial walls, the trick is to find a single piece large enough to work on while joining solar cell pairs.
ü Light - has to be sufficient to clearly illuminate the project surface mentioned above. If you are in a fixed area where you will regularly work, LED lighting is excellent for producing high lumens output as well as brightness. LED fixtures are currently very expensive; a typical four foot LED style fixture is $100 at big box home improvement stores. A more economical way of getting LED light from an existing 48” fluorescent light fixture is to purchase special 48” LED bulbs that fit exactly into the existing two-prong slots. You must do some simple rewiring of the fixture, basically bypassing the ballast, and for $40 you get the full benefit of LED lighting. One could also simply install an LED light bulb into a standard clamp-on work light and have very strong light for under $20. Enough about light, you simply need quality illumination.
ü Air Circulation - because toxic fumes are created during the soldering process, there needs to be a source of fresh air to evacuate any lingering smoke or fumes.
ü Organization - is a very important trait to have in this trade. Keeping your work surface clear of trash, clutter, wire clippings, anything that is foreign to the project should be put away immediately after use. Things tend to get broken when too much clutter starts to encroach on the work area. You control the space so there needs to be tight discipline regarding the sanitation and organization of the work area. If you maintain strict standards over the organization of your work area, getting cooperation from people with whom you cohabitate will be easier. If they see a pile of goo, they won’t feel overly hesitant about tossing on a few more trinkets or trash, and in doing so being totally unaware they just smashed your newly completed string of cells. Conversely if the work area is clean, orderly, and free from clutter, others will be less likely to deposit foreign matter because it will be slightly more obvious who started the trash pile?
ü Secure Storage for the WIP - as I touched on at some length earlier, nothing is more disheartening than to shut down working on your solar panel for the night only to discover that someone in the family missed the memo about randomly tossing sporting gear into the garage upon opening the door, or some similar mishap. I suggested plastic storage totes earlier, the type that slides under a bed as an option but there are plenty of choices available in the storage category of products. You simply need to find what fits into your budget and your environment. If you are industrious, shelves built along the wall in the garage, or high up along the perimeter of some least-used room in your dwelling; just anything to get them up and out of the hands of curious siblings, children, and/or guests.
ü Dust - won’t be found anywhere on the production floor in factories producing solar panels. In such environments the air is purified, filtered, and air curtains help to keep new particulate from being introduced into the production areas. Most of us will be working in our garages, bedrooms, living rooms, and weather permitting, even outdoors. It is unrealistic to expect to create dust-free work space when handcrafting your solar panel in any of these environments but you need to take reasonable steps to keep the solar cells as clean as possible. The nature of this type project means it will take possibly a couple days to complete a solar panel. During this time, some of the completed solar cell pairs, and completed strings will have to sit idle while you complete the remainder of the components. Dust will accumulate on the surfaces of the solar cells, the longer they sit, the heavier the coating. This is why it is so important to have a sealable container in which to store the WIP during these periods. Even covered and inside a container, some dust will accumulate over the upward facing surfaces. Not to worry, a layer of dust at this point can be dealt with successfully, you simply do NOT want to encapsulate or install the final covering until the dust has been removed. How you ask? Gently brush the dusty surfaces with a soft paint brush; I use artist brushes made by Plaid, soft nylon and natural fiber bristles that gently push away the dust without the risk of scratching the delicate surfaces. They say you should avoid using canned air for fear of static electricity, not something we are concerned about it this application. You may also use a Shop-Vac in conjunction with the hobby nozzles (pictured on the next page) to give you pin-point precision when cleaning the WIP. Why is dust a concern at all? It is well known in the field of electronics that dust acts like an insulating blanket because it traps heat underneath the layers. Heat is a universal enemy to electronic equipment to the extent I am willing to bet at least one of us has lost a desktop computer to the ill-effects from dust. Heat causes computers to slow down as their internal self-defense protocols react to heat by shutting down in a process known as “Throttling”. This process acts on a computer CPU (central processing unit) like “shock” does to the human body when facing some significant injury to include those resulting from excessive heat. Shock preserves blood for use exclusively by vital organs like the brain, cutting off the blood supply to other organs because the body sees them with lesser priority in terms of the developing crisis. Throttling helps reduce heat in the computer by shutting down functions that are contributing to the heat which is manifest by slow performance and at worst, a completely blue screen while the computer tries to cool itself. Dust should be eliminated especially in the final stages where the long “strings” are being installed onto the substrate, and certainly just before adding encapsulants. Dust may reduce the curing effectiveness of encapsulants, compounds, silicone sealants, so as you see, there is nothing positive about dust making it onto your final product. The dust removal should be done each time you pull a new solar cell out to solder the tabbing wire strips, dusting with a brush both sides of the solar cell prior to soldering as well as the glass soldering surface.
ü Gloves, or Not - if you have watched a few YouTube videos on the subject of DIY solar panels, you will have seen every possible combination of work environments, work surfaces, and of course, some glove supporters. Gloves are tools used to help prevent certain contaminants from being introduced onto the solar cell surfaces. Human hands transmit grease, sweat, and oils from our bodies onto the surfaces we subsequently touch as we proceed through daily life. Surfaces we touch collect all manner of contaminants that go beyond the scope of this book, but the issue is of great importance to the task at hand. Suffice it to say that we touch a wide variety of objects in our travels to include our own bodies. Even if we washed our hands before commencing work, human nature will have us touching our faces, hair, clothing, and each time our fingers come away with detritus of several descriptions. I can universally guarantee that nothing on those fingers I just mentioned will have any positive effect on your solar panel. In fact, the contrary is true when you consider that bodily fluids are sometimes very oily or greasy in composition. Dare I suggest an experiment dear reader? Could I request that you wipe one finger across your cheek and forehead and then take note of any sheen on the finger? I am sure there is a study somewhere on the number of times we touch our face, head, etc. throughout the day because we all scratch, wipe, or swipe at ourselves all the time, probably absentmindedly. Either way, formerly clean hands have a way of picking up foreign matter as do hands covered in a glove. Gloves can give a false sense of security because the wearer knows that the solar cells are now safe from oily human skin, but they perhaps don’t realize how often those gloved fingers are touching faces, beards, hair, and the like. After the glove itself becomes contaminated the point of wearing them is lost, so I feel it is best to be educated about the need to have clean hands, clean work area, and if you work clean, your final product will be clean.
ü So You Spilled Soda on…or some other mishap whereby something splashes onto a solar cell or a string already completed. You can clean the liquids off with a very gentle dabbing motion using a soft, absorbent cloth, or tissue. Once the offending liquid is removed, the residue can be cleaned from the solar cell by saturating a small portion of a very soft rag, or Q-tip and gently dabbing the areas in need of attention with rubbing alcohol (isopropyl alcohol).
ü Residue - The reason for using isopropyl alcohol is that it dissolves most oils, alkaloids, gums, and other things I cannot pronounce, but best of all, it evaporates without leaving behind oily residue. The occasional finger print will come right off with this method. I cannot resist the urge to reiterate the warning about leaving your WIP out in the open when you are not actively working on it. It is one thing for you, the craftsperson to slop a glob of chili onto your solar cell, but quite another to come out and discover some unrecognizable, formerly liquid, silver dollar-sized glob of something on your WIP.
Safety Is A Primary Concern At Every Stage
I do not know the skill level each of you has with regard to working safely around electrical components. There is no question that electricity can be deadly, for example, a review of the U.S. Department of Labor website revealed that in 2013, 71 people were killed by electrocution while working in construction jobs. This is an OSHA report and thus we can extrapolate that these were job sites filled with hazards. Homeowners fare little better according to the Florida law firm Leesfield Leighton Rubio Mahfood, who advertise that over a quarter million Americans are hospitalized annually after an electrical shock of which as many as 14% will die from their injuries. When you put these two sets of statistics into the perspective of our lifelong pursuit of Doing-it-Ourselves, we straddle the fence on the issue of injury statistics. I don’t mean we are confused about which side of the fence to fall; we are exposed instead to both categories of hazard, construction trade and that of the homeowner.
Handcrafting solar panels represents risks you need to know about especially if you are a parent who will be supervising a younger person performing this activity. Once the solar panel is completed you will undoubtedly want to put it to work, and why wouldn’t you? It is an exciting day to look forward to! The solar panel itself is live, electricity generating unit the moment sunlight strikes it at the appropriate angle whether you are ready or not. Connecting the solar panel to a deep cycle battery represents a new set of risks and dangers, if mishandled because of a battery’s high discharge current capacity, and the presence of caustic compounds. Inadvertently connecting cables to the wrong polarity or accidental contact with battery terminals by tools or jewelry can cause an arc, a sudden release of energy capable of melting steel wrenches upon contact. Battery charging generates hydrogen which is combustible at 4% concentration, especially hazardous without ventilation. If you intend to mount your solar array on a roof, the risk now includes falls from the roof or the ladder used to get there. The ladder in question must NOT be made from aluminum since that material conducts electricity if a live wire comes into contact with it. Once your array (multiple solar panels or modules joined together) is up and providing power, if not grounded properly (or not at all), there is a shock risk which also might escalate into a fire if conditions are right.
Hopefully I haven’t shocked or frightened anyone away! I mention the things above so that you are aware of the risk inherent in working with electricity. Things do happen on occasion that are unusual and that defy logic, like when you have done everything right, yet you are hit by another driver who was doing everything wrong. Outside of your control is, well, outside of your control, which is why you need to be in control of those things that you can. The idea is to prevent accidents that result from carelessness, working too fast, a sloppy work environment, taking shortcuts, or any of the other behaviors that are fairly certain to have been responsible for previous accidents somewhere. There is a reason for the absurd warnings we see on everyday products such as those on firearms instruction manuals that specify not to point a weapon at oneself. Seems pretty self-explanatory and awfully big on common sense yet, if you search on YouTube I promise you that you will find footage of people who not only shot themselves while looking into a gun barrel, but then posted the film! Therefore I must place graphic warnings of what could happen to you should you take shortcuts, or act on impulse when you really don’t know what to do next. If you run into a situation where you absolutely do not know what the next step is, STOP, get your instructions out, double-check, go online, email me, but do not simply guess. If you do, there is an even chance that whatever the step is will come out incorrectly and the resulting error could be costly in terms of wasted time and effort, not to mention cost.
ü Extension/Power Cords - must always have all prongs present; never use one that has any visible damage to the plug or surroundings. Never use a cord that is crimped, torn, cut, or has wires showing through the outer cover. Inspect the power cord for the solder gun, lights; as well as anything that you plug in to an outlet to complete your project. Don’t overload a wall outlet, extension cord, or surge suppressor by “piggybacking” in order to plug in your soldering iron or soldering gun. Piggybacking is when you increase the number of outlets available by adding outlet extensions on top of outlet extension (see photo example on the next page). The cumulative draw on such a mass of clustered outlets results in concentrated heat sufficient to start a fire. You need to be able to extract electricity safely, with a fresh surge suppressor that is plugged directly into a wall outlet or receptacle. That will ensure a steady supply of consistent power without placing the entire structure in mortal jeopardy. If you are a parent with very small children, perhaps toddlers, you are aware that chewing on extension or power cords is a common behavior. According to Lynda Liu with Parents Magazine, in 1997 (I know, a tad dated) more than 6,000 children were treated in hospital emergency rooms for electricity related injuries. Seventy percent of them were under the age of five and had either chewed through a power cord, or stuck a foreign object into a wall receptacle. Just be aware that when you plug in the soldering iron it would be a good idea to triple-check that you have devised some method for keeping that cord out of harm’s way. Lastly, when changing solder tips on either the iron or gun models, unplug them while performing the change-out. You can imagine why…
ü Heat - is a factor with soldering equipment since the tip must achieve a temperature sufficient to liquefy solder. For example, the specific solder I use has a melting temperature of 350°. At such temperatures skin is no match and serious burns can occur if contact is measured in fractions of a second. No rational person would intentionally expose themselves to such intense heat but if perhaps an unsecured soldering iron (the round cylindrical type), not sitting in a rack becomes airborne and lands in your lap because a passerby tripped over the power cord. The human brain is going to respond to this with respectable elasticity but it has to rely on our clumsy limbs to affect our rescue. Reacting with lightning speed we would snatch the offending soldering iron from our lap but in those few seconds a very serious burn will have occurred, one requiring immediate medical attention. ALWAYS USE A STAND in conjunction with a soldering iron because they are hot all the while they are plugged in, even when not in your hand. That makes them a very wily risk which demands your respect!
ü I like to use the soldering gun because I control the heat. When actively soldering, not only does the area directly under the solder tip get extremely hot, pretty much the entire solar cell becomes too hot to touch. You will not be able to hold down tabbing wire against the solar cell for alignment prior to soldering because your fingers would receive third-degree burns. Thus, the reason for the “Probes and Pokers” on the equipment list. They are the instruments used to hold tabbing wire down while soldering. So important is this tool that I strongly recommend this tool in every enthusiast’ toolkit. They will safely allow you to manipulate the tabbing wire and hold it gently in position while soldering. The surface you are soldering on will also become very hot for a brief time as you solder. That means you cannot solder on a surface that will combust, or melt from the soldering iron. So any table that is plastic MUST have your glass work surface between the solder activity, and the table.
ü Fumes - are present when the solder reaches the temperature necessary to liquefy it. The need for ventilation is paramount as the resulting smoke from solder should NOT be inhaled directly. A fan may be used to push the offending smoke away, perhaps a desktop model that is battery powered (rechargeable batteries of course) or an actual smoke extractor which pulls the smoke away from the work area and filters it in case there are impurities. If you have sensitivities to the odors or fumes, such a device might make your soldering activities worry-free and worth the expense. We will be using lead-free solder which spares us from exposure to the toxins most notorious for causing illness namely lead. You can take comfort in the fact that the MSDS (Material Data Safety Sheet) information for the encapsulating materials we offer for sale is NOT hazardous material and this fact is confirmed by the U.S. Department of Transportation.
D) Know When to Ask for Help
I had an instructor who used to tell the class, “The only foolish question is the one you don’t ask”.
Here is where the males of our species, yours truly included, invite all sorts of grief to come crashing down on our heads because sometimes we are just too proud to admit when we don’t really know what to do next. I know, some of you are chuckling while others may want to punch me in the teeth for putting something so sacrilegious into this book. I admit that in the far distant past, there was a time when I would charge ahead on a project, and if I encountered obstacles (translates into the fact that I didn’t really know what to do next) I would do what I thought was common sense or fit with what I thought I knew in general. Those are the type of projects that may have had to be done over, but done properly the SECOND time. You will not encounter many obstacles after reading this eBook if any at all because I tried to anticipate your obstacles based upon those I experienced early on. Between the written instruction, still photographs in the margins of this document, and the exclusive How-To video library there will not be a question unanswered regarding this handcrafting process.
I have covered some of the hazards one might encounter while handcrafting a solar panel but my list is not all-inclusive. There are many situations and combinations of factors that could lead to injuries or accidents and thus, an all-encompassing list would require multiple volumes. We take risks every day, some we are aware of while others catch us completely by surprise. If you are new to the exciting field of photovoltaics, you will probably not stop with one solar panel, you will go on to build your custom array. Your participation in photovoltaics places you in contact with electricity generating equipment, power storage devices, grounding, and some basic wiring tasks. It would be extremely wise to explore methods for learning basic electrical theory in a systematic and comprehensive approach. There is so much information online however, I fear that sometimes we learn just enough about a topic to pose a threat to ourselves if we base our research ONLY through Internet sources. Book titles on residential electrical systems, solar power, photovoltaics, and virtually every aspect of the electrical trade can be researched, but you have to do the reading. What I strongly recommend is to enroll in a formal training course, something you take at your own pace, perhaps an online course, of the caliber such that upon completion you could pass the relevant state contractor test portion. I am referring to Mike Holt Enterprises where you can find a full line of courses ranging from topic-specific to complete electrical contractor test preparation. They are good people who will help you achieve your education goals and don’t hard-sell you for anything you don’t want. They can be found online at www.MIKEHOLT.com or by phone at 888-632-2633. (Unsolicited endorsement)