A Solar Panel Question :: Doc Ellis Are You Out There ??

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So a buddy + relatives just bought a new property with an old house.

The house needs a bunch of work,  including new roof.

Currently there are a batch of solar panels on the existing roof,  and the new owners have no interest in running those.

I might be able to haul those panels off,  for free,  but is the effort worth it ??

They are twenty years old, and I can provide more details in the next day or two.

My guess is that if they are getting rid of  the panels,  electronic stuff might come with (inverters and cables + ?)

PV Panels have a shelf life. Might not be worth it, but I'm sure you could run some DC electronics like a BetaMax or maybe a Salad Shooter.

Not worth it. While Moore’s law doesn't exactly apply, it serves as a reference to technological advancement.  Solar panels lose 1% efficiency per year on average. 

If you have unlimited  time, it might be worthwhile    

The brief web-search I did gave me figures of .5 -> .8 % degradation per year,  but I guess I'll have to go over there with a voltmeter and check them.

I imagine there are inverters and stuff that come with the panels.

From what little I know,  the PV panels put out DC voltage and the inverter converts that to AC current to run your fridge, stereo etc.

I'm thinking they might be used to run a pump out in the far field,  for irrigation.

Most well pumps run on 240 volt AC power;  there must be some 24-48 volt pumps out there.

Moore’s Law is referencing generational technological advancement of electronic components. Forward thought from transistors and applies to semiconductors still.

Batteries are electrotechnical, not electronic.

Crazy setup a Jerseyland dude built some years back,  Solar-Hydrogen house + cars / mower / motorcycle.

https://www.scientificamerican.com/article/hydrogen-house/#

Cost him $500 K but grants covered $400 K.

Jerseyland is actually one of the top three Solar states up there w/ CA and AZ.  The days of state $$ to offset installation costs are pretty much over though.

Regardless of old tech and degradation, I would grab anything you can get.   It's free! 

If you can get your hands on the inverter, I'm SURE a guy like you can find multiple great uses for it.

As a DIY project or supplemental system it's definately worth it.   I don't know if I would permanently mount them all on a roof as a full house system... But I sure could have me some fun with a couple panels.

I'm thinking a portable system you can throw in your truck for field use or even camping.   Or maybe powering a shed or remote building on your property.

The only caveat is its if it's a grid tied system.... Those inverters wont work without mains power as a reference.    It will work to lessen your power bill, but you won't get paid for surplus and it's not likely to pass any inspection authorities.

1 or more salvaged car batteries, a panel or two, and a sub-$100 inverter/charger.... You could be blending smoothies, charging phones, and have tunes all weekend at a festival if its sunny.

Or For about $20 on ebay u can get a charge controller and draw 12v off a battery to power/charge personal electronic devices.  Or just use 1 panel and the controller as a battery tender on a vehicle to maintain float charge.   If youre slick, you might even be able to hack and retool them into smaller backpacking sized panels with a little luck.   Depends on the construction of them, but I've seen it done.

Fun stuff.   

You Rang ?I have seen panels that the white background has turned black and I fixed the connections and they still put out what they were rated .The were 35 years old . So the answer is yes yes yes . The farm can use them even if you have to get a new charge controller . They could be a good brand and I know most of the old manufactures .The new ones that are the Chinese are crap . Let me know the details . Those panels can be run in series and then stepped down with the charge controller to the voltage desired . This could be a score 

(Double post edited out)

Agree on chinese controllers being crap... But for 20 bux they complete a portable system on the cheap.   I would not install them in a house...  But in a small system they have merit imo.  You just need to monitor them on a basic level.   Theyre not very efficient either when compared to higher quality stuff.   Just monitor them for failure or overcharging.   Doesnt make sense to me to buy a super expensive controller just for a small camping system.

MPPT is really the way to go... But i wouldnt touch a cheapo Mppt controller and the chinese products are a waste of time there.  For basic charging on a small portable or auxilliary system, pwm controller from china gets the job done.   Def would not advise for a permanent install, though.

 

Thanks for all the feedback.  I still haven't seen what's on the roof,  but know that they are coming off for new roof.  I'll take a ride out there this week and see if there are inverters and charge - controllers still present.  Latest news is that they ~might~ want to hold on to the panels,  but we'll see.

Looked at some Solar discussion boards such as this one:
https://www.solarpaneltalk.com/forum/solar-panels-for-home/solar-panels-...

Lots of good advice out there.

I've got a meter on the house and one on the Barns.  If I did a grid intertie setup,  panels would go in the field near the Barns where there's Sunshine all day.  House roof is too old  & weak to support extra weight,  and gets a lot of shade.  Also the Well tanks are in the Barn,  which has a modern (4-5 year old) breaker panel.  Well / pump / tanks are new and would provide some mild irrigation for field crops,  as well as my domestic water supply.

An off-grid application here would be enough panels to run a DC well pump for irrigation in remote fields (no utility poles out there).  That sort of makes sense in that generators are fuel-hogs,  and field crops need irrigation when there's full Sun.

Stu Let  Me know what you have And i will hook you up .I have a few charge controllers  in the shop you could have  . I also could hook you up on any parts you need we have tons of stuff in the shop and any thing you wanted to purchase you could get at my cost . Don't forget storage! All day sun will charge a good size bank of batteries which will give you more output than the panels.  I have accounts for rack co's and inverter co's I buy direct so let me know, and if your feeling rich I have battery accounts .Fingers crossed you get the panels   viva we don't use anything other than mppt  in our world grid tie or off grid small brand name controllers are not that expensive 

Thanks Doc.

This week I'll visit  the place and look at what # of panels there are,  how many rated Watts,  and if there are any Inverters or charge controllers.

Right now I've got no useful data,  just ideas.

Appreciate all your advice very much.