Help with installed solar array

**ButchDeal** · 09-20-2017, 08:38 AM

Are you sure about those battery sized? 30ah? so you have two 24V battery banks of 60ah each
also are you sure about the solar module count? 63? would expect it to be an even number if they are spit between two systems. but if they are roughly equal it would seem that each is trying to 9.28kW of solar on an 80a MPPT shoved into a 24V 60ah battery bank.

The battery can't take that much, and the Charge controller is only rated for 80a but there is 386a coming at it.

Has this thing ever worked?
What kind of inverters are there?

if you really have 63 X 290w pv modules 18.27kw, you are going to need larger batteries, more charge controllers, and best bet would be to convert it to 48V battery.

**J.P.M.** · 09-20-2017, 10:46 AM

Start by downloading, for free, and reading "Solar Power Your home for Dummies". That'll clear up a lot of the basics for you, including how much power a system might produce as well as a lot of details.

Also, PVWatts has Puerto Rico pretty well covered. Run that after reading the help/info screens a couple of times for a pretty good SWAG at long term average output.

On batteries, follow Butch's comments.

**SunEagle** · 09-20-2017, 10:53 AM

I agree with ButchDeal. It looks like your battery system is too small and you do not have enough charge controllers for an 18kw 24volt system.

Even a 48volt battery system would require close to 400amps of chargers which would be 5 of those 80 amp units.

**adionne** · 09-20-2017, 11:49 AM

Thank you everyone!

You are confirming my suspision. The wires from the bateries to the mppt are hot. Not understanding this installation i increasedthe wire size

The batteies are deep cycled Trojan T105 - 20Hr rate is 225 ah. Sorry for misleading you

4 6 volts are connected in series to obtain 24 vdc then another 24 vdc bank is parralled so the total should be 500 Ah. Not sure how to go about this as it will charge for a short time. Slo they tap the 12 VDC instead of the 24vdc I dont see any advantage to this.

I also read everything I could on the subject. What I cannot anwer somehow - is if all these panel where to be restrung properly according to component use, what is the maximum load i can sustain for 2 days without sun. These panels are used to drive small pump to oxigenate fish tank where the water is use as a fertilizer. Plus there is a chicken coop with high efficiency fans.

Not being familiar with this - I would like to come up to them with the best solution possible. Meaning getting the most AC power out of these panels. The mppt supply is less than 150 vdc which respect the maximum voltage input of these inverter.

There are no one with enough knowledge there to maintain led acid batteries. Hence i am thinking to propose ion batteries. So really I am looking at a cost effective proposal with dollar figure to pass on to that organisation. Hopefully they will be able to raise the money to bring this installation to the best. I m returning there in a month to complete the AC installation around the fish tank (nema 4 boxes and conduits...) and ground the solar panel somehow.

I am open to suggestion or where to look for purchasing. What is the maximum AC output we can acheive? I know that the battery cost will be very high

Hope for your guys suggestion i.e number of possible inverter and batteries.

Also... if the mppt takes 150 vd max that would mean 3 panel in series (46Vdc open) x 3 = 138 vdc @ 8 amps then 10 of these strings in parralel to get 80 amps???? this is the way I understand this? or 10 single panel in parrallel to produce 80 A @ 46 vdc so I would need 6 X 80 amps inverters?

They want to put in a trade school to teach trade to the local and wood working equipment has been supplied. Probably will run each machine individualy and worst case of one of them is 200 @ 5 hp

Ok i need to be put on the right path here. Too much reading!

Andre

**ButchDeal** · 09-20-2017, 12:20 PM

Originally posted by adionne

Also... if the mppt takes 150 vd max that would mean 3 panel in series (46Vdc open) x 3 = 138 vdc @ 8 amps then 10 of these strings in parralel to get 80 amps???? this is the way I understand this? or 10 single panel in parrallel to produce 80 A @ 46 vdc so I would need 6 X 80 amps inverters?

you seem to be confusing inverters and charge controllers as well.
What brand and model of inverter do they currently have?

A few problems with your math there. The Charge Controllers are rated for the output. at 24V not at the string voltage.

Thus why you should look to convert the battery bank to 48V
and even then you are going to need MORE charge controllers. 5 total charge controllers.

I would go with a single battery bank, stack charge controllers, and stack inverters.
you will need new inverters for 48V and additional charge controllers.
I am not sure what you are talking about them tapping the battery at 12V but that is bad, don't do that. pull all the loads off the battery at full battery voltage.
you will need fuses on the batteries to the inverters, and fuses to the CC, as well as combiners with fuses for the solar arrays.

**adionne** · 09-20-2017, 02:02 PM

Butchdeal

No doubt that I am confuse hence i am reaching out. I have not installed any of this just trying to sort everything out. Its my first experience with solar and understand that there is a lot of know how and expertise that I don' have.

The mppt are made by Wave Techology and are rated 80 A and the maximum input voltage is 150 Vdc. I found an outback charge controller manual that seem to be identical and read it.All the recommended connection like circuit breakers does not exist. No ground either. When I was there i installed foru ground rods and gorunded the AC inverter neutral and installed a 20A GFIC.panel. I need to finish the 120 because they have done the outlet outset with regular outlet boxes with no polarity and ground.

The 3.8 kw dc/ac inverters are labeled PROTRACE PAWER INGENIER 3.6 and there are no manual. the other one is INVERSORES Plus no rating

I understand that chage controller regulate and maintain the amperage out of the batteiries and the other converts. I have no idea why the installer use the center (12 vdc) of the batteries to connect the mppt and the inverters. I wanted to reconnect everything to 24 vdc but I had zero understanding at the time.

If you had this amount of solar panel what would you buy and where can I get a quote for it. I will pass it on along whoever wnats to help me recommendations. I will redo tha installation out of my pockets.

Best regards

**adionne** · 09-20-2017, 02:03 PM

I have some photos would you like to see them and hoe can I transmit them to you?

**adionne** · 09-20-2017, 02:05 PM

I am also looking for ion batteries because of the minimum maintenance

**ButchDeal** · 09-20-2017, 02:36 PM

Originally posted by adionne

I have some photos would you like to see them and hoe can I transmit them to you?

I think that would help people help you here.
you can attach the photos to a post here but clicking on the paper clip icon to the top right when adding a comment. It is the left most of the fonts, and smiley face.

**adionne** · 09-20-2017, 04:57 PM

Battery_superflex xg6-30.PNG DR_Battery_bank.PNG DR_Components.PNG 20170309_113749_resized (002).jpg

Here are the pictures. I hope one of you can help me select and price the proper equipment. I am totally grateful for your help and knowledge

Andre

**Mike90250** · 09-21-2017, 12:46 AM

Originally posted by adionne

.........There are no one with enough knowledge there to maintain led acid batteries. Hence i am thinking to propose ion batteries. So really I am looking at a cost effective proposal with dollar figure to pass on to that organisation. Hopefully they will be able to raise the money to bring this installation to the best........

Then you are done. Lead Acid batteries have been around in common use for nearly 100 years. They only need distilled water and charging, Li-Ion batteries need complex monitoring systems to prevent them from burning up, low voltage or high voltage can ruin them quickly. If there is nobody to work with lead acid, there is even less chance Li-Ion will be successful for you.

**Mike90250** · 09-21-2017, 12:55 AM

Originally posted by adionne

Hello All
I am looking for help as I am not familiar with solar technologies. I am a master electrician helping a charitable organisation in the dominican republic to complete/make safe a solar installation on a farm. I am donating my time

Here is what has been insttaled

63 X 290 w panels @ 35 Vdc (45.6 V open) 8.2 amps. They are facing south and angled by the roof

I have check via the nl web site and the sun time average is 4.88 - 5.22 kw(h)/msq/day which will be 89 kw(h)

The solar seem to have been spli in two

There are 2 MPPT 80 amps chargers (By wave technology) and i have no manual
There are 2 x 3.8 kw inverter that produce 120 vac
Each MPPT drives 8 batteries 6vdc @ 30 ah connected in (4 in series (24 vdc ) then in each bank in parrallel
Nothing was grounded and the wire sizing seem to be incorrect.

I am looking for if this is the best installation? If I was to redo the whole thing from scratch how much AC (AH) can I produced if done and size correctly. The load is unknown so I like to know what can I get out of this array (220/120)

Thank you all

63 panels @ 290 W = 18,270 W (18 Kw) That's HUGE !! In a 4 hours solar day, you could easily harvest 73KWh. My house consumes about 10KWh daily,
If this was a 48V DC system, you would be charging batteries with over 300 amps, well beyond what your existing chargers can handle. (They will work, but you are leaving a lot of un-harvested power unused)

**adionne** · 09-21-2017, 08:38 AM

Mike

Good Morning! Yes this is what I suspected. Again, humbly I am not a specialist or engineer on solar. I am helping a non-profit organisation to correct the electrical installation and provide the best solution regarding this solar installation for them. So I am reaching out to the expert.

What would you suggest that I do to get the best quote/design and price to harvest this 73 kw(h)? that is a lot of power. I know the cost will be high but I think that the fund can be raised bit by bit. Meanwhile i am reading on the subject but I needed a starting point. When I go back there in November, I would like to correct the installation that is there (24 or 48 vdc) and reconfigure the array for the exsting mppt and inverters.

Are ion battery the best solution to store this power? I have read that they last a long time and are maintenance free. The people out there have no expertise.
When you say 73 kw(h) do you mean 608 A at 120 for 1 hr? My understanding is that in a 3 days of tropical rain, if the system is design correctly - I could supply 8A/hrs for 3 day?. That would mean a generator set as a backup in order to keep all the pump and areration fan running? They are totally off the grid.

In the solar universe are quotes free or what will it cost me to get this engineered?

Best regards and thank you for your help. Thank you also for the link!

Andre

**Mike90250** · 09-21-2017, 03:12 PM

Anything can be accomplished, if you have enough $$. If the PV array is truly 63 panels @ 290 W, you have a huge install, and are only able to harvest a small amount of it.
In your situation, I would NOT even think of Li-on batteries, because nobody there knows how to configure them, and when they are mis-configured, they generally burn up. If they are abused, they burn up. If they are "adjusted" they burn up. If someone wires a couple cell phones to one, it will burn up. No Li-on is my recommendation.

What gear is available locally ? Any golf courses, with electric carts ? Golf cart batteries may be your best solution. 8 of them gives you a 48V system. 16 would double the size. That's where I would start looking, building a 48V system, 48V inverter, 48V MPPT charge controller, and use 9 panels wired to the charge controller [ 3s 3p ] Then replicate and make as many groups of 16 batteries, 1 inverter, 1 MPPT Charge Controller, 9 PV panels as you can afford. You have way more panels than you can harvest into batteries. Something that scale, will need a full time person to manage, keeping an eye on things - I beleive it's too much power to just let watch over itself.
Possibly forklift batteries would be an option, if you can get those at your location. You need a local, qualified, engineer, I can design it in the States, but if you can't get the parts locally its pointless.

Help with installed solar array

Help with installed solar array

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