Setting up a battery backup power system

[EL34]

I have a really cool project that I am working on

I am in the process of setting up a 2400 watt solar array (6 x 400 watt Bi-Facial panels) that goes to my Sol-Ark 15K unit
The Sol-Ark is hooked to 6 x 48 volt server rack batteries for a total of 600 amp hours of storage (100 amp hours each)
The batteries are Lithium Iron Phosphate and are 5120 watt hours each, so 30kwh of storage

This is what everyone seems to be using now for batteries
You can run them to zero if you want and they don't explode like Lithium Ion batteries
Gone are the days of 12 volt lead acid and golf cart batteries

I had Duke power set me up on the variable rate for electricity usage and it has 3 zones for electric power prices
It is way cheaper to use the grid on off hours
Currently I am recharging the batteries at the cheapest off hour rate and turning off the grid to the shop during the work day
The shop is running on batteries all day long, but the solar panels will charge the batteries soon

I am installing a transfer switch so I can back feed to my house from the shop for power outages
The Sol-Ark can also have a generator hooked up to it for off grid charging if you do not use the grid
If you have a generator with an electric start, the Sol_ark will start the generator automatically if you want it to
Basically, the Sol-Ark replaces all the things you need, like inverters, etc
Everything is in one main unit.

The Sol-Ark and the batteries talk to each other over a network and I can see all the info on browsers

The first partial month of running the shop on batteries dropped the electric bill $50 and that was not even the whole month of usage
It will probably drop to zero $$ after I get the solar panels hooked up and charging the batteries

I don't have it selling back to the grid because my system is hooked to my shop building, not the main 200 amp panel that is on my house.

Here's a few pics of my system

[acheld]

Very cool setup.

I've considered something similar -- but every time I talk with an installer around here I get a different answer about what is best, and the general design of the system.  Along the lines of "(Product X) is best because that is what I use. . ."

So, how did you design this?

[EL34]

The inside of the Sol-Ark is a work of art
Two battery bank inputs
3 solar string hookups
Generator hookup
Load output
Grid input
Communication board for different formats
Wi-Fi and Lan hookup for viewing over the web on a browser
And the manufacturer can do software updates over the Lan connection

I can also program it via a browser

[EL34]

Very cool setup.

I've considered something similar -- but every time I talk with an installer around here I get a different answer about what is best, and the general design of the system.  Along the lines of "(Product X) is best because that is what I use. . ."

So, how did you design this?

Forget about installers and save some cash
I did all this myself

It's a no brainier these days and so easy to do yourself
Sol_ark is the shit and EG4 are the batteries everyone seems to be using

This forum is the place to get that info
https://diysolarforum.com/
Sol-Arks are not cheap but you are getting top shelf hardware and you don't have to piece together a bunch of stuff and hope it all works together

Links
https://www.sol-ark.com/

I bought my batteries here and they threw in the rack cabinet for free and $300 flat shipping from Texas for a 800 pound load.
https://signaturesolar.com/shop-all/batteries/

I bought my Sol-Ark here because they had a free shipping deal
https://practicalpreppers.com/product/sol-ark-15k-the-ultimate-off-grid-solar-inverter/

[EL34]

Here's a cheaper copy of the Sol-Ark
Not exactly the same, but pretty cool
Check out this guys other videos

He is a awesome source for info

[EL34]

Here's a chart showing Duke powers rates for two different seasons
I had to sign up for this by calling Duke power
They just set up my meter over the air waves because I already had their most recent meter with air wave communication

You may have to have a new meter installed
So 8pm to 11am are the cheapest rates for me right now during summer rates
It changes for non-summer hours

[EL34]

Here's one of many wiring diagrams for the Sol-Ark depending on how you want to set it up
You can put them in parallel and do other fancy things with them

[shooter]

Nice!


I did a 1K solar, mis-mash panels, 12 deep cell, lead acid batteries in the early 2000's.  took my art studio, electronics shop, and small grow room off grid.  worked well, the batteries were a pain, always inspecting, testing, filling.  I plotted over time an average of ~1.2KW per day input, never really monitored the load.
I still have 400W's in panels, but would like to replace the 4 with one 400W, The OutBack 60A charge controller still running fine except the LED panel is winking out.
I still have a "fish-raising-tank" on the drawing board for this year, but the year is getting away from me!  Hoping to have the tank run 12months a year  with pump, filter, feeder and heater.

[EL34]

A lot of hardware has changed since way back when

The rack batteries are awesome
There are lots of 400 watt panels on Amazon
I got Bi-Facial panels which will absorb ray on the back also
I will be spreading white reflective plastic down behind mine to bounce all the rays back up
Mine will be ground mounted on tilting racks so you can adjust the angle

[PRR]

Here's a chart showing Duke powers rates for ....

Wow!

Last time I had a ToD rate, it was simply midnight to 6am. Like your old holiday-lights timer: just two settings.

On paper. But every time there was a power outage (say, the burning transformer on our street) the electric clock inside the meter lost its setting.

When ToD was new, the meter readers knew about this and re-set the clocks when they read the meter (this was 1980s!). But the ToD tariff was very old, not available to new customers, and the young meter-readers didn't know (or care). So we were getting cheap electric in the evenings. But I checked the clock in case of further drift. Eventually the company said "That's it!" and put us on regular 24h tariff.

FIVE periods per weekday?? (And weekends?)

[EL34]

I have been waiting until my batteries are under 50% and then I will turn the grid connection back onto the Sol-Ark so it can re-charge the batteries
I charge after 8pm or early in the morning up until 11am
Then I will turn off the grid before 11am and use the batteries for 2 days before charging again

This can all be done automatically via programming, but I have a manual grid connect switch right now
The solar panels will take over the charging when I get them set up
After than, I will have the Sol-Ark control all that via programming

[shooter]

I will have the Sol-Ark control all that via programming

Lithium is a whole different beast than Lead-acid when it comes to charging. I have control over a given range for each parameter, (~100 parms) on the OutBack, does a great job tracking both solar in and battery drain/charge (Power point tracking they called it). Never had to Aux charge, (gen, grid) my batteries, the array got anemic in the winter though, maybe averaged 700W a day, vs the 1.2Kw in the summer.


so the panels are 400W including reflected light?  That's the 1st i've heard about using reflected light, but I haven't looked in awhile.

[EL34]

so the panels are 400W including reflected light? 
That's the 1st i've heard about using reflected light, but I haven't looked in awhile.

Yes, they are bi-facial, so both sides can make the juice
You probably would not use them on a flat roof, but I am using ground level tilting mounts
You can adjust the tilt angle a few times a year

Maybe there is better info here where I got them?
You can also see bi-facial panels on Amazon
https://jjnsolar.com/products/2400-watt-bi-facial-solar-panel-3-set-of-400-watt-solar-panels-total-8-pieces

[shooter]

 
I had 2 lengths of 2X4's "props" winter, summer, the panels were hinged at the top, prop them with the 2x4s, seems like the angles were something like 50 deg. and 75 deg.  I had a 200W panel, can't recall the substrate, they would pull in a couple amp on a full moon, the silicon one's winked out before sunset.

[EL34]

Looks like I had an older usage chart in reply #5 above
Duke power has two new charts for power usage rates

This one is for May 1st to September 30th
I added some red text with the current rates

Critical peak is not shown
Duke says they will notify in advance if they need to go to that rate

[EL34]

Mine is running slower this morning
Normally, I am about 750mb down and 30mb up

[EL34]

I programmed my Sol-Ark to charge from the grid from 1am to 6am and then not use the grid from 6am to next day 1am
I can do all that via a web browser which is pretty cool

The first test was last night and it worked great
The batteries were charged back up to 94% when I came to the shop this morning
Looking forward to getting the solar panels installed and then not using the grid to charge.

[EL34]

I got my 6 x 400 watt Bi-Facial solar panels set up in what used to be my garden

They are making juice during the short window they receive sun
They are currently tipped at about a 15 degree angle which is what the interweb says my Lat and Lon for June should be
I have some long timbers that I have to set under them and bolt them to
Right now they are just setting on the ground via the aluminum tilt brackets

The most I have seen them producing so far is 2200 watts
I only get good sun from about 10:30 to about 3pm because I am surrounded by tall trees
They make 300 watts starting at about 9am with shaded light