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.

The panel in use on the back yard storage shed measures 20 X 40 inches, produces a maximum of 63 watts and was completed mostly on the kitchen table. The next panels will measure 30 X 60 inches and produce a maximum of 144 watts. The kitchen table won’t work with the larger panels for a couple of reasons: FIRST is “she who must be obeyed” and she ain’t going for that again. SECOND is with 30 X 60 inch panels the kitchen table ain’t gonna fit. Considering there will be more than one panel built, a dedicated surface for securing different jigs to speed production seems a good plan. Garage cleaning is calling (arghhh).

Once garage cleaning gives sufficient space for the project it’s full steam ahead. I’ll start with one panel (the money thing gets in the way once again). Wild axed guessing tells me day to day needs will require four to six panels to keep a travel trailer battery bank rockin’ n rollin’. So even though one panel won’t do for the trailer it is both a start and good to have in case of an emergency situation. Having an electric source (even if limited) versus sitting in the dark with no electric seems a no brainer and in the meantime it is one step closer to the goal.

Peripherals include a battery bank, charge controller(s) and DC to AC inverter(s). Depending on your purposes the battery bank can be little as one battery or many as you can justify. Charge controllers come in a wide variety whether off the shelf or DIY. For starters I plan to build a simple charge controller capable of handling 20 Amps. It should work well with up to two panels. If you have no electronics hobby experience you will be ahead of the game buying an off the shelf unit. When it comes to DC to AC inverters, they can be DIY projects but there is generally no advantage and may actually be more expensive than commercially available units. Due diligence researching charge controllers and inverters is recommended. Give careful consideration to the cost of buying ready to use units versus component costs and personal time invested building your own. You may well conclude the only thing gained by doing it yourself is the pride of successful accomplishment.

Next post will include some nitty gritty basics of the panel design planned for this project. Small details regarding materials and dimensions can have an effect on per panel cost. This post is way over 500 words already, so stay tuned for the next installment.

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!