Glass + Sylgard fail anyone yet?

After doing some research (but not attempting the feat ...yet), it seems as though the longevity of Sylgard 184 is not the problem with DIY panels... it's the cost.

At $50 per solution, the cost is prohibitedly high. Couple that with solar cells, aluminum frame, glass (tempered - not even Starphire), junction box and wiriing... the cost is almost equal that of a UL certified solar panel - which currently can be obtained at around $2.00 / watt.

Sylgard will last - but $50 per panel increases the $ / watt by $0.63 (assuming you're putting together an 80 watt panel). Almost an increase of 30%!!

What's the water vapor permibility of sylgard ? The less permable it is, the longer the panel will last.

Most epoxies, painted wood and RTV's are very vapor permable, and a panel made of those won't last, except in the dry southwest or Mars

Yeah and power output is good at -60 F with a CO2 atmosphere

Don't have any numbers. But in this dow corning document they are selling the vapor permeability as a good thing. Section 3.3 Silicone Corrosion Protection.

"The ability for silicones to transmit water vapor rather than absorb it prevents moisture from being trapped at an interface."

This one is interesting:



"To significantly reduce moisture ingress requires a true hermetic seal, the use of an encapsulant loaded with desiccant, or the use of a very low diffusivity encapsulant."

Sprinkle desiccant before sylgard?

Yep when you use the same materials, methods, and million dollar machinery with trained operators like manufactures use, you can make a commercial grade solar panel that will last 20 years with a warranty.

Kind of like counterfeit money. You can get away with it for a while, but eventually you will face the music.

Good Luck.

You sure are one negative person Sunking. I'm am not trying to make a commercial grade panels. Ordering a pallet of panels would be cheaper and certified to boot. However, I want to build a panel or two, to learn and have fun. Why not have it last as long as possible in the process? I would still argue that it's very possible for a diy'er to make a panel that would last 20 years. There's just not enough data for you to deem it impossible. I'm optimistic that glass+sylgard encapsulation is one method.

OK fair enough So what is your point?

I am a Professional EE of 30 plus years experience and have been there and done that. If you want to play with toys to learn, more power to you, that is how you learn like I did. Fact is is you are playing with toys of not much useful application. But if you want to scale up to a useful application, the LAW of PHYSICS, ECONIMICS, REGULATIONS, and REALITY will kick your butt into shape.

OK so now you have been told, now go learn what I am talking about. It is your money and time. Prove me wrong and you will be rich beyond your wildest dreams.

Care to bet? You got 20 years to do it before i die if God blesses me with 20 more years on this earth.. Here is a good snipet of what you want to do and economics lesson.

If you want to build a battery system to generate 1 Kwh pr day of power (12 cents per day) it will cost you $3000 real money DIY for the first 5 years assuming your DIY panel last that long. Then after 5 years you will pay another $1000 for a new battery for the next 5 years.. Now do the math.

Good Luck

SK

Whoa !!

I think the point here (or it's the point I'll make) is that making a DIY panel is great, you learn about soldering, thermal stress, expansion, series circuits, parallel circuits and all kinds of stuff.
But at the end of the day, we'd rather see you work with $50 in parts, understand it will be a toy, and enjoy it while it lasts.

But we do see, is folks buying reject cells off ebay (they are 100% rejects, belive me) with no idea what they are doing. Constructing elaberate schemes to mount, and hold the cells. Installing blocking diodes wrong way round. Wires to nowhere. Investing hundreds of dollars and days of time.
That's fine with me, but don't ask me to fix it for you when in 6 weeks, power starts to fluctuate, and smoke comes out the back.
Small = Good learning and science
Large = good learning, lots of time, $$, and disappointment, and maybe a house or garden shed burned down. Dam solar stuff, never worked right. I built a 300W panel and my beer fridge was still warm. And I have 700# of dead batteries I have to haul to the canyon and dump because the town dump fees are too much for scrap lead.

We're trying to let you know small and learning is great. Big and elaborate, you need solid plans, and to have taken the small steps first and KNOW why soldered battery connections are not good.

Jumping in with both feet, Ready, Fire, Aim. ?? and then wondering why it does not work, serves no one.

Mike

I hear you Sunking. I'm a MSEE also, albeit emag focused. I bet you see lots of people excited about finding cells on ebay and think they will make a panel for 1/10th the price. Probably gets annoying hence your harshness. I'm more of the research and plan type. Hell, I spent a good year researching and planning my 6kW automated brewery.

Anyway, my main point is that these companies have to over-engineer their panels or they are out of business. They can't afford to take risks. That's where us diy'ers come in. I'll take you up on the bet, although just for bragging rights because I don't estimate a high chance of success.

You are spot on correct, and I am glad you seen through it and my cynical humor.

However I will tell you what really frost my pumpkin. I see a lot of folks on here and other RE forums who have bought some piece of crap book like Earth-4-Energy or some other such witch craft book, go out and buy a bunch of cells on ebay, a couple of batteries, a $100 inverter and expect to build a few panels, disconnect from the grid, and live life happily ever after with no electric bills. It breaks my heart to have to tell them they just threw away a bunch of money and have been scammed.

Case and point about 2 years ago on another forum a lady from Indiana had Her electric turned off because she could no longer afford to pay it and was out of work. She went and spent $1200 dollars on an off-grid battery kit. It consisted of a 200 watt panel, a charge controller, and a 500 watt inverter.

She was inquiring what she had did wrong in the wiring, because it would trip the inverter every time she turned on her electric heater, one of those 1200 watt floor jobs you buy at Wallmart to put under your office desk to keep the feet warm. So I asked Her what she wanted to do and expect.

She replied all she needed was to run her electric heater, electric blanket, alarm clock, and her curling iron and blow dryer in the mornings,. She could not figure out why the inverter would shut down and wanted help wiring it up to work.

Without going into a lot of details I told Her there was nothing wrong with the equipment, and she had wasted her money and would spend winter without electricity, and she would have been better off using that $1200 to keep Her electricity turned on for the next two years warm and cozy.

She did not like that answer at all, stormed off and went to other RE forums only to be told the same thing.

So yes I will sound the alarm and spare no feelings when I see BS and scams. I would rather make you mad by getting your attention and saving you from making a huge mistake, than sugar coat it and tell you what you want to hear.

As for building a 50 watt panel to learn. That is fine, especially a high school or college student working on a project. But in the end, it is an experimental toy to be thrown away in a year or two.

Just call me Simon Cowell or Gordon Ramsey of EE, if you are a hack, I will call you down on it, and tell you the truth.

Disagree but not 100 percent

I am not sure I agree 100 percent. I agree that one cannot make a purse out of a sows ear,although there are construction materials that would allow one so inclined to buid a system that could operate a small fountain pump, or some garden lights, shed lights, maybe operate a radio.
I beleive that the panels can be constucted to last, possible not the 20 years as the commercial models do, after all they reaseach the most econimicaly vialble mehod of constructing the panels. The want to make money, period. A diy with moderate expitations could set up a system, although the cost is not a huge savings.

Mike, you say that 100% of cells on ebay are rejects, where would you recommend purchasing them from? I guess I got duped, i bought 36 of them..

No way you can buy prime cells, for scrap prices, either they are rejects of some sort, or stolen from production. No company would sell prime cells for 1/2 of their value. Think about it man, you are buying from some person called MrCheapSolar with an email address. Not Sanyo.

Production line fallouts, or stolen.

I am interested in the comments that good solar panels can't be manufactured DIY. However, I'm not convinced. If I'd taken that attitude with technology I used 30 years ago, I wouldn't have spent the last 20 years selling the new technology that I developed.

I'm about to manufacture a couple of my own panels, to see if I can do it at lower cost than the commercial units. I plan to do it well, using glass and Slygard. I'm not pretending it is cost effective for normal domestic use, but may serve my purpose in a remote area with no electricity.

My message is - be aware that it may not be so easy to get it right, but many significant developments have been made by people who "have a go", and aren't bound by conventional thinking.