The rear panel was fabricated from several acrylic pieces glued together using silicone adhesive sealant. For some reason, one glued edge pulled away and warped toward the fragile solar cells breaking six of them. Oops! Two lessons learned: 1-sometimes the bargain basement method isn’t a bargain. 2-silicone isn’t the right adhesive for the job. Future back panels will be one piece even though my original panel may have been just fine if bonded with a different adhesive sealant material.

Most types of silicone adhesive sealant have three strikes against them when used in making solar panels: 1-It has poor adhesion to acrylic or polycarbonate. 2-Once silicone cures additional silicone will not adhere to it. Discovering a gap where there shouldn’t be one means disassembling, removing all original silicone and redoing the process. Yuck! 3-The method of encapsulation I’ve been considering uses conventional silicone to seal the backside of the cells. Not too desirable when the plan was to adhere the cells to the back panel with silicone and it doesn’t stick to itself and is marginal at best adhering to acrylic. Thus a fresh challenge: finding flexible adhesive sealant products that adhere well to aluminum and acrylic or polycarbonate.

One product immediately sprung to mind. Marina job experience using 3M 5200 marine adhesive sealant makes me believe it a good candidate for the purpose. The spec sheet says aluminum may need priming for best adhesion. It also bonds well to acrylic and polycarbonate. Considering it is frequently used below waterline, I’m willing to give it a try without priming. A tube of it is in possession and will be used in at least one of the larger panels.

The second product called Lexel was found in a local hardware store. A Google search turned up a data sheet with lots of info. Bonding strength to both aluminum and acrylic or polycarbonate though possibly a bit lower than the 3M product appears quite adequate for solar panels. Lexel is also less costly, probably because it is not designed for marine use.

Either product seems suitable for bonding and sealing front and rear panels to aluminum perimeter frames. It’s tempting to clamp the front and back panels in place until adhesive cure is complete and forget about using additional means of securing the panels. Only one problem: I’m an over kill champ. So just in case the adhesive sealant lets go I want to insure neither panel can fall off.

Oh, about my ‘over kill champ’ claim. Just ask my brother. On second thought I’ll ask and if willing he may spend a little time at the keyboard explaining why I have legitimate claim to the title.

Anyone with suggestions, experience building their own solar panels or knowledge of adhesive sealant products suitable for DIY solar panels and willing to share please feel free to comment. They will be much appreciated.

Even though I’m not one of those “go green – save the earth” types, this link pretty much explains what motivated me to explore building a first solar panel. Based upon what was learned depending on solar panels for our electric needs would be economically impractical.

Next time you’re looking at one of those “google ads” implying you can get free electricity by building a $200 solar panel to power your house and sell electricity back to the electric company keep the following in mind: Some things you can believe while some should be taken with a grain of salt, others with a block and still others with the entire salt mine. Just as there is no free lunch there likewise is no free electricity.

From what I’ve seen “going green” is about getting the green from my pocket more than exercising conscientious stewardship over the environment. The last electric bill I saw represented 33 days during the last part of November and first part of December 2009. Some of the coldest weather of the year was during that time and we use electric heat. Per day average was 77.5 KWH. Some days exceeded that and others were less but for the sake of this let’s stick with 77.5 KWH/day. A solar array with 23 panels, each producing 144 watts 24 hours/day would yield 79.488 KWH/day. Of course that would require sunlight around the clock so let’s figure winter time 5 hours light per day at 144 watts/hr and we’ll need 108 panels to get 77.76 KWH/day. Of course that is assuming sufficient light for panels to produce the full 144 watts 5 hours each day. Nice concept but not necessarily realistic. Figuring each panel costs about $250 to build 108 panels comes to $27000.

Solar panels sometimes function 20 years or longer. Commercial panels often carry a 10 year guarantee. Assuming 10 years with $27000 initial cost would come to $225/month just for the panels. Every year beyond that would be bonus bucks. Then again we need to add costs for array structure(s) to mount panels, battery bank(s) that probably won’t last 10 years, charge controller(s), power inverter(s) and various and sundry wires and connectors, not to mention efficiency losses. Then there is personal time and effort researching, designing, building and organizing everything. Yep, it all adds up.

Economics may not be the reason for building a solar electric system but there are a couple good reasons that encourage me to keep building. Aside from temporary outages due to storms, floods, earthquakes and other natural causes let us not discount the possibilities of terrorist actions, governmental intrusion or even total economic collapse. No, I’m not predicting anything but don’t discount the possibilities. In all of these circumstances I prefer to have a source of electricity that requires no commercially produced fuel. Gasoline, diesel, LP and natural gas could be too expensive or difficult (perhaps even impossible) to obtain.

Because sitting in the dark wishing I had prepared sounds highly undesirable, the next phase begins.



Not the Highest Quality Picture But You Get The Idea

First and foremost problem was the manner used to fasten the plexiglass front panel to aluminum frame. You see plexiglass and aluminum both expand and contract at different rates. Plexiglass is prone to cracking around holes drilled in it even though deburred. It appears my error was in not drilling the holes a bit larger in the “plexi” to prevent hole edges from pushing against the securing screws during cycles of expansion and contraction. Although not severely cracking the plan is to replace the original plexi come spring and adhere it in place using a non-silicone adhesive/sealant that will be permanent without screws.

Second problem was using aluminum channel (the type used as edging around plywood panels) rather than solid aluminum bar for the frame. The channel has less than desired rigidity after assembly and is less than ideal for accomplishing a water and air tight housing for the solar cells. With enough attempts I’m confident satisfactory frames could be produced using channel but advantages of solid bar stock for future panels is personally more attractive.

Third problem is actually not a problem but something to consider when planning and building your own solar panels. The 3” X 6” cells used in the first panel provide a maximum of about 63 watts from 36 cells connected in series. For charging and maintaining the 12V battery power needed in the back yard shed that small panel is quite adequate. Over the winter months the need is mostly for lighting from time to time and maintaining the motorcycle batteries. Cold as it is being this winter there will be little intensive work done in the shed. So the max. 63 watts provided by the smaller cells is proving to be a successful first solar panel experiment.

In the works is the next generation solar panel project/experiment. There are 6” X 6” cells available claiming 8 Amps (or 4 watts) per cell. Thirty-six cells in series would yield 144 Watts at ideal conditions (wild guess is in the real world between 85 & 125 Watts is more likely). The plan is to supply enough power for a 20′ to 30′ travel/camping trailer. Y’know what? Even for a do-it-yourself type doing it all on the cheap that strikes me as both a tall order and big dollar outlay.  Running a refrigerator and occasionally a microwave or other electronics will make charging a large enough battery bank a tall order. An air conditioner and electric water heater would make it an even taller order. None the less my fascination for this project continues.

So the second solar panel project/experiment is in process. The panel will: measure 30” X 60”, have solid aluminum frame, encapsulated cells and detailed text, graphics and video for each step of the process.

140 Watt 30″ X 60″ Solar Panel Layout

Over the past couple days attempts to add pictures have failed miserably. Some kind of blog software-hosting provider glitch I’m guessing. The hosting guru is digging around looking for the culprit but so far nothing.  I’ve postponed  this post long enough, time to publish it and edit pictures in when the problem gets resolved.

Ahhh! Sweet success!

In the course of these posts the information and explanations will be kept as non-technical as possible. My experiences include beginner hobby electronics projects which at least provides a good mathematical background and practical electronic soldering experience. Add basic woodworking and metal working/machining to that and I’m confident building my first solar electric panel will be a learning experience and hopefully of benefit for a few Rantsville readers as well..

OK let’s start with a couple definitions as they will be used throughout this series:

Solar Cell: As used within these posts refers to a photo-voltaic cell which is capable of generating approximately .5 Volt when exposed to bright light. The surface area generally determines the amount of current (amps) the cell generates in bright light.

Solar Panel: A number of solar cells linked together so as to increase the voltage and wattage output. For example if you link 2 cells in series, each producing .5 Volt at 3.5 Amps the resulting output is 1 Volt at 3.5 Amps.

That’s the down and dirty basics. The intention for the first solar panel project is an experiment to help determine the number of panels will be needed to maintain sufficient charge in a bank of batteries in order to operate a power inverter for the appliances we want to use without relying on an electric company. Individuality will dictate what those requirements are, thus I will not even attempt to define appliances you deem necessary that we may not. To begin with all I need is a test subject.

Over the summer much spare time was devoted to converting the powder coated steel framework of a Harbor Freight tarp covered storage structure into serviceable winter storage for my ‘95 Goldwing. Price was right and the work exhausting but it’s a sturdy structure with both mine and my brother’s bikes inside. An extension cord can be strung through the back yard for lighting but I prefer not to do that to prevent the cord from falling victim to our snow blower. Over the winter light will be needed when accessing the shed for whatever work we need to do, plus a couple of motion sensor flood lights to keep honest people honest.

The absence of snow blower fodder while still having lights, minimal security and (not necessarily scientific) data collection easily justifies this solar panel venture. Wednesday when my check gets banked I’ll buy 36 solar cells from an eBay seller. Properly configured they will provide 18 Volts at 60+ Watts in bright conditions. I’m curious to know if that will be sufficient for the shed.

Part 2 to follow.

Other projects captured my interest and I thought nothing more of it until two days ago when I happened upon a link that took me to that very same site. Well that got me questioning how logical it would be to buy that information, build the “under $200” wind powered generator and use it to provide some part of our electric use. So I did a bit of rough calculating.

Information download: $50

Wind generator: $200

Wow, shouldn’t take much time at all to pay for itself. That is until you dig into the FAQs. You see the unit is built with the “goal” of generating 500 watts at winds of 20 MPH or above. Um, I’m here in North Dakota, on the plains, we get quite a lot of wind but I can guarantee we seldom see 20 MPH sustained winds. But OK, for the sake of this let’s just say we have 500 watts generated 24 hours per day. In the course of a month (30 days) that would mean 360 kilowatts. At a current per KWH rate of $.05/KWH there would be an $18 per month saving from my electric bill.

Sounds good so far don’t it? With higher output unit we could supply all we need for the house and even sell the excess back to the electric company. But there’s that 20 MPH wind to consider. Let’s get closer to realistic and say we have pretty consistent 10 MPH winds. Now we’re only generating 250 watts and maybe saving $9/month. Oh and did I mention the electricity generated is probably not 120 Volt 60 cycle alternating current so you’ll need to charge battery banks (not inexpensive) and use an inverter just so your appliances will work. Inverters are notoriously inefficient so after generating that 250 watts and charging the batteries you may end up getting 125 watts (I don’t know, possibly more or less) from that 500 watt generating system. If you decide to build a much higher capacity unit at much higher cost, the cost of charging equipment, expense for greater capacity battery bank(s) and the much larger inverter needed to supply larger amounts of electricity to your appliances adds up.

Of course the bottom line question is will it pay for itself? I sincerely believe it will but I also believe before that break even point you could have paid the electric company for a long time. You likewise will have repairs and maintenance above and beyond the initial costs and may need to pay qualified people to assure your system is properly connected.

Tempted though I may be, I think it’s not for me. I’m sure glad there are people out there willing to undertake these endeavors and I expect incredible advances are being made every day. I’m fascinated and that fascination will never go away.