Took the Solar Plunge
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What about the backside's of the panel?? I work on boats and that open back just don't cut it. Was thinking of enclosing it with some sheetmetal to help reduce the "Sail effect" That 1.5" Lip is unsat design in my opinion. The cheap panels i got really need angle re-enforcements in corners for me to feel confident about them withstanding 100mph winds..Flimsy lightweight aluminum it seems. I may do some bracing as well where the pole mount meets the back.
Is tracking worth it?? -
No tracking. I wouldn't even say "tracking" and "100 MPH wind" in the same sentence.
I'd say mount the panels either flush with some other sturdy rigid surface or box them in so that wind cant get under them to create lift.
Where EXACTLY are you mounting the panels and why EXACTLY can't the batteries be mounted very close to them?
I've built south facing solar generators that are mounted on a wooden "wedge" of about 26 degrees sitting directly on the ground with the batteries under the panel and the whole box anchored for exactly same reasons - To keep the wind from carrying it away, to keep all components close and make cleaning snow off the panels easy.
Generally there is no advantage in raising the panels other than to keep clear of shadows if they exist or to avoid flooding damage.
Elaborating on the length of wire run. The high voltage AC side can be long. 70 feet is ok. Only the low volt DC wiring must be kept short.
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Yea anything is possible but you are correct. Stabilizing that weight would need a mighty positioner at 100mph. Truthfully i thought about a ground hugger but i dunno if i like it. I may mount more equipment on the pole. And yes i could build the battery boxes right onboard for stability. I liked the variable angle is why i chose the pole mount. I am not married to it. I was planning on mounting some other gear onboard like a weather station(weewx) and antennas.
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Weather stations can still be mounted on poles even if the solar, battery and inverter are on the ground.
People mount solar panels in the air all the time and get away with it, but 100mph wind…. Sounds like recipe for disaster.
So, I'm a tiny bit confused. Is this going to be on a boat or a yard?
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Smallish Yard just a home project…
I appreciate your system sizing advice. So you saying roughly one 12V-125ah battery per -100W/5A max@17V/12V panel? or 4 panels for 500ah of battery? All roughly.
I don't plan on inverters. Just DC loads... I seriously eyeballed the 200W class panels by the big names. I just want to experiment for now.
I may just use an old lawnmower deck for temp mounting of batteries and panel.
And i just pulled the 100mph figure out of the air. My point was i want something sturdy and not blowing away at 70mph gust.
Thanks for the great advice. -
My cousin did a tracking unit that only utilizes freon gas and properly placed "exposure tubes" and air shocks from a vehicle. Got it from "Popular Mechanics" magazine from the 70's He uses it to this day and for the last 25 years.
It supplies 30 amps in the top of the day and supplied their family of 4 off grid all this time till the kids moved out.
Luckily he messed up the gas and the panel makes it way back to the east overnight and is waiting for the sun first thing. Id love to find that article.
He is on top of the hill and the wind has never been an issue. I suppose he got lucky.
Deka makes terrific solar batteries as well.
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You have to measure the current coming off your panels to know what you are getting.
A 100w panel in full sun at the equator will probably get you 100w or 8 hours or so.
In some northern place, it may only put out 30 or 50 watts and may not get many hours of sun.
So, you have to figure, up north you will need 2x the panel (at least) as panel advertising my lead you to believe.
You only get a few hours of sunlight - So, lets say for instance its 4 hours average for your place.
So you discharge 24/7 but only charge for 4. so your charge rate needs to be 6x higher than your average load.
Not only that you vane to compensate for load. A great lead acid battery only stores about 60% of what you put into it. 40% may be lost.
So you have to take your original calculation of 6x the load and multiply by x 2.
So, if you average load was 10w you would need about 120w input during your 4 hours of sun to keep things working well.
So yeah - More panels.
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Deka - I've heard good things but have never used them. No experience with those.
Good thing is I'm pretty sure what you have, if you add abit more solar panel, will easily run a small 10w pfsense (-:
(The above comment is a blatant attempt to prevent deletion of thread due to irrelevance to pfsense boards)
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Thanks for every-ones advice. I'm sure the Renogy panel i got probably only work half their rated capacity, I saw Amazon writeups stating their inefficiency. For $150 for the kit it was worth it for me just to learn with.
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When we looked into sun tracking most advice (and our own conclusions) was that it's cheaper and far more reliable to just add panels. My friend adjusts the angle of his panels a few times a year manually. Never tried a maximum power point controller, kept meaning to bulid one.
This is general discussion:
Feel free to talk about anything and everything in this board.
:)
Steve
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I need to build another big one soon. I'm thinking that in the Philippines I can totally disconnect from the grid if I want - At 25 cent per kw/hour it should be nearly three times as economical as in the USA.
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Would you build an array with a "Branded panel", Hoping in 20 years they will still be around to honor warranty? Or would you go generic.. Like you said earlier Poly looks to getting better.
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Great question.
I like reliable name brands.
My Astro panels are like new and its been a long long time.
I think kyocera might be a good compromise between efficiency/price/quality.
I'd bet they will keep working for decades unless someone hit them with a baseball bat.
If you don't mind spending a little extra, With BP Solar you can't go wrong.
I'd probably go with the Kyocera cells myself though.
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We used BP Solar panels but only because my friend already had them. They must be at least 20 years old and have fallen off thd boat or been hit by stuff countless times, still going strong.
Steve
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Yeah - My kids used to walk and play on my panels in the back yard - I wish I'd taken pics. Its near 20 years and they are still going also.
The frames, glass and backing are as important as the cells themselves.
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"pfsense" doesn't occur anywhere in this thread. Perhaps it belongs elsewhere.
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@gonzopancho:
"pfsense" doesn't occur anywhere in this thread. Perhaps it belongs elsewhere.
General Discussion Feel free to talk about anything and everything in this board.seems to be the right place ::)
I probably could power my pfsense box with a panel and a few batteries.
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Ive thought many times of powering my pfSense (used the correct stance there see that) box and data center with a solar solution. My cousin also needs a pfSense box and probably would not see any drastic reduction in current to the battery letting it run all day. They have more sun throughout the year than I do as Im im near Seattle. Im thinking of building him a pfSense box that runs on 12vdc so that the solar array could keep his pfSense router live and filtering all the bad stuff the new Centurylink DSL connection he has to his place has to offer out.
pfSense mention count- 4
;D ;D ;D :o
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I have multiple Alix 2D13 pfSense running 24/7 from solar+battery feeding 12V DC direct to the appliance.
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Sounds reliable (-:
Compared to a UPS, how much power does that use? Bill every month?
How well does that pair up with the "low power pfsense" that people love so much?
Sounds like a marriage made in heaven to me.
