HELP! My DIY Solar mistakes

[Dayrobber]

I mentioned to several self proclaimed solar know it all knuckleheads. Here's where it got me.
1.I said I wanted a 1000 watt system. Not one said anything about 12/24 and so on for panels,CC's, Inverters,wire thicknesses,PV rated...and so on.
2 Mistakes, wrong wiring gauge and type.
They use speaker wire from cars on 50ft runs with 20 broken panels and are happy with tv and phone charging.
I'll stop there.
I have 3 100w poly panels 12v.
Epever 40 amp CC
Industrial 2000/4000 PSW Inverter (118 degrees, Southern California)
Here's the kicker. 4 12v 101ah EVERSTART 24DC batteries 690 mca.
My wiring I must say is now great. Crimpers, terminals,length, gauge.
I need to run,and this is rounded up. 1000 watts for 14 hrs. a day. Batteries are first I'd say.
I can spend 400 a month. I need this done by New Year's. HELP!
Bring on the Pain.

[Mike90250]

What is the charge controller ? PWM or MPPT ?

When you say you need 1000w system, can you describe your loads:
Blender. 900w for 5 minutes a day
TV 110w for 6 hours
phone charger 10w 4 hours
laptop 70w 6 hours

70w x 6 h = 420watt hours
Convert your loads to watt hours, and then we can continue.

Because of losses, 100w panels only produce 80w at solar noon, closer to 60w the rest of the day. So each 100w panel is likely only able to harvest 350 watt hours each day

[Dayrobber]

Hi. Well just the fridge/freezer is pulling 500 watts. It's 118 degrees in the California desert. It run constantly and is insulated inside and out and has 10lb ice blocks in it. By next summer. I'm going to want A/C. My power tools are all 15 years old and plug in. Then add the things you've spoke about. I rounded high. So freezer and A/C running 24/7 got me there. Just being safe I guess. That's why I'm here. Tired of mistakes. Appreciate you taking the time for those like us.

[Dayrobber]

And it's MPPT. THANKS AGAIN

[Mike90250]

A fridge/freezer, is not an insignificant load. It always moves from a low budget cell phone charger system, to a much larger system. If you are adding air conditioning, that's a major step.

so with your fridge #'s 500w x 24h = 12,000 watt hours (12Kwh) That's my summer time power budget, running 2 firdges and a freezer, and pumping water 5 hours a day

So first, you need to replace the freezer with a Energy Star freezer, rated about 1Kwh daily. Add your hot climate, call it 2kwh daily. That's a HUGE improvement, and will save you loads of $ on batteries and PV panels.

My personal system is in my .sig below. 2 pole mount arrays, 2 60A MPPT charge controllers and 48V battery bank. I think you could get by initially with a single array and a small battery bank, and plan on doubling things as you grow. Add a 2nd PV array, charge controller and when the batterys fail, double the bank size. In 2 or 3 years there may be some respectable advances in battery tech you would want to use.

For now, I would suggest bite the bullet and go with a small 48V system. I'm partial to the Schneider/Conext gear and would suggest starting with the
XW+ 5548 , which is a 5.5kw inverter, 110A charger when running off your 240V generator and needs a 48V battery bank

https://41j5tc3akbrn3uezx5av0jj1bgm-wpengine.netdna-ssl.com/wp-content/uploads/2019/08/DS20190807_Conext-XW-120-240-V-Datasheet.pdf

You will also need a SCP or a Combox, or a Gateway to program & personalize the gear. And i'd suggest the Midnight Solar Wiring box ( E-Panel )
which makes a snap of all the connections with charge controller(s) main battery breaker, and AC buss

If you mount panels on your dwelling roof, you have to meet some extra code requirements, but a ground or pole mount only needs a fence (maybe)

Batteries - I'd suggest starting off with a minimal set of 8 golf cart batteries. 6v 200ah which would give you a 9,600wh battery, with 4kwh usable. (50% discharge)

PV, I'd start with a 2Kw array, which should easily get you 8kwh daily harvest, scale back to 1KW of pv, and you have 4kwh daily, but that may be cutting it close.
Panels, look for the 40 - 80V grid tie panels in the 250 - 300w range, you already have a MPPT controller, which at 40A, 48v should handle 2Kw of PV. Be sure to verify the PV input voltage limits of the controller and don't let your array configuration exceed that on a cold frosty morning.
here's a link to a PV / controller sizing tool. your controller may have it's own calculator site http://www.midnitesolar.com/sizingTool/index.php

Oh, off grid air conditioning is not going to be cheap, but with proper construction (ICF insulated concrete forms) you should be in good shape.

Good luck.

[Dayrobber]

Mike99250. Thanks but you might of misunderstood me. I am already in 1500 bucks,live in a non mobile RV. On disability and can't start over. Right now I need good batteries and whether to buy more 12v panels or switch now to 24. Same with battery bank. There's no water in the desert. One little piece of concrete that used to be a store still has an address UPS will deliver to. That's a 3 mile walk in 118 heat 1 way. Everything must literally come from Amazon. Thanks though for your time. I'll work it out.

[NEOH]

Mike99250. Thanks but you might of misunderstood me. I am already in 1500 bucks,live in a non mobile RV. On disability and can't start over. Right now I need good batteries and whether to buy more 12v panels or switch now to 24. Same with battery bank. There's no water in the desert. One little piece of concrete that used to be a store still has an address UPS will deliver to. That's a 3 mile walk in 118 heat 1 way. Everything must literally come from Amazon. Thanks though for your time. I'll work it out.

The size of your inverter ( in watts ) will determine whether you use 12 volts, 24 volts or 48 volts.
With 12 volts, the wire gets very fat & more expensive with the larger inverters

You have:
3 @ 100w poly panels 12v.
Epever 40 amp CC
Industrial 2000/4000 PSW Inverter
4 @ 12v 101ah EVERSTART 24DC batteries 690 mca.

Walmart Everstart batteries are cheap, but do NOT last very long with nightly Deep Discharge Cycles.
I think, GOLF CART Batteries are a much better choice.

Your 2,000 Watt PSW Inverter ( at 100% power ) needs (min) 166 AMPS = 2,000 watts / 12 volts
You Solar Panels generate at 20 AMPS = 80% x 3 x 100 watts / 12 volts

I would consider increasing the Solar Panels from three (3) to six (6).
You need to operate all appliances from Solar Power, from sunrise, to sunset and also recharge the battery bank.
Does the battery bank recharge to 100% everyday?
How many hours does your battery bank operate when the sun is down?
1 hour at 100% Inverter Load?
2 hours at 50% Inverter Load?
4 hours at 25% Inverter Load?

You state, "1,000 watts for 14 hours" ?
Do you turn-off the inverter for the other 10 hours ( ie every night ) ?

Once you buy and install all 12 volts stuff, it is expensive to convert over to 24 volt or 48 volt.
The existing Solar Panels can be re-wired in series for higher voltage.
Or you can keep the 12 volt system for most appliances and design a separate 48 Volt system for the A/C ?

Given your $1,500 investment in 12 VOLTS, maybe you need to add an acceptable 48 Volt solution for just your A/C needs.
Look for a 48 VOLT 12,000 BTU 1,000 Watt A/C unit made for RV's - variable speed & high efficiency !!!
6 x 300 Watt Solar Panels + 8 x 6 Volt 225Ah Golf Cart batteries might give you 15 - 16 hours of A/C per day.

[Mike90250]

You are wanting to do something, that as you have found out, does not work. A small 12V system cannot handle your loads. You fell into the classic: Ready, Fire, Aim from ignorant advice.

24V system is the minimum for what you want, 48V would be better. The more batteries you add in parallel, the worse things will become. The first month is fine, but as batteries age, parallel forces them to age prematurely.

Running your batteries so low that the inverter shuts off, damages your batteries. Deep cycle does not equal Run till Flat. Deep cycle is at most, 50% depleted .

6v, 200ah golf cart batteries are better than the ones you are using.

Any money you throw into the 12V pit of despair, is lost.

What is lost on most you fool videos miss, is that all motor powered gear (air conditioning, fridge......) use motors with less than ideal Power Factor (PF) This appears as extra load to the inverter and a small inverter may be able to manage 1 motorized appliance, but won't reliably handle the stress of 2 of them. Eventually, both will be on at the same time and the inverter shuts down.

I'm just laying out the facts and my experience. You can keep going down the 12v rabbit hole, or bite the bullet and do a major upgrade that will result in a reliable system.

[Dayrobber]

Thanks Mike. That's what I need to hear. I have never taken these batteries down below 12.6v. Last night I ran there fridge till 1am. Batteries never got below 12.8. I have absolutely no obstructions except the occasional cloud. My batteries right now with fridge,fan,and phone accessories charging and I just ran an electric drill. My batteries are 13.2v and 16.2 amps. It's 11 am and I'm already at .71kwh. I think I'll rub the panels in series,leave the batteries at 12v. I'll grab 3 more panels and use this system for everything but A/C. I have plenty of wires,cables and connectors.

[littleharbor]

[QUOTE=Dayrobber;n402523]Thanks Mike. That's what I need to hear. I have never taken these batteries down below 12.6v. Last night I ran there fridge till 1am. Batteries never got below 12.8.





What are you measuring your voltage with? 12.8 volts is what a fully charged FLA battery would be sitting at If you were pulling a load on this battery overnight I would question the 12.8 volt reading afterward.

[Markyrocks69]

You should look into getting some Nissan leaf batteries. I'm planning on getting an rv in the next year. Everyone wants Tesla batteries but they're crazy expensive. It looks like you can get an entire car worth of batteries from a leaf (24,kwh) for 3-5grand? Which with that kinda juice youd obviously need more panels to keep the batteries happy but youd basically be able to run a mini split ac system, a fridge lights and a computer..and probably a few other things no problem. I know money doesn't grow on trees but that's the kinda setup you should be aspiring towards.

[Ampster]

You should look into getting some Nissan leaf batteries. I'm planning on getting an rv in the next year. Everyone wants Tesla batteries but they're crazy expensive. It looks like you can get an entire car worth of batteries from a leaf (24,kwh) for 3-5grand? .....

An old Leaf pack is probably only 80% of capacity so you are only looking at 20kWhr which is $0.25 per Watthour. Tesla modules are on Ebay for $1200-1500 which is a price of $0.30 per Watthour. That is not that crazy expensive when you consider that the thermal management alone on a Tesla pack is far superior than that in a Leaf. To me that improves the odds that a Tesla Module is going to have less degradation.

[Markyrocks69]

An old Leaf pack is probably only 80% of capacity so you are only looking at 20kWhr which is $0.25 per Watthour. Tesla modules are on Ebay for $1200-1500 which is a price of $0.30 per Watthour. That is not that crazy expensive when you consider that the thermal management alone on a Tesla pack is far superior than that in a Leaf. To me that improves the odds that a Tesla Module is going to have less degradation.

I'm not really sure where you're getting these numbers but the only Tesla batteries that I had found which i did see individual modules for 1200 ish and those are like 5 and change kwh. So based on that I'd assume youd need at least 4.5 of them to be equal to the leaf capacity. Basing it on the leaf being 80% vs 100% is kinda unfair bc the Tesla battery is going to have some degradation due to over charging and under charging. I didn't really think of it in those terms bc if you're sitting around 3500 for 24kwh of leaf and 4x Tesla modules would be around 18-21ish kwh depending on what you get. For around 5 grand. Theres still quite a disparity there for the difference you could replace quite a few batteries or be well on your way to another car worth of batteries...Idk I think this is probably the deal right here. Even to buy and resell individually, wish I had 10 grand laying around bc that's exactly what I'd do.
https://rover.ebay.com/rover/0/0/0?m...2F183648047184

In a situation like this it might be worth the effort of getting into the resale business. You could undercut everyone and still make a killing. Basically get your batteries for free

[Dayrobber]

Mike99250. That was Suppose to say 12.3.
Got a coupl Siemens solar panels.Both look like crap. Looks almost like Air brushing or Marble counter top.They diodes look okay. I cant test until I get mynew RMS meter. Put them on a PWM and shows 5.1 amps. Rated 4.4.Do you know why the panels looks burned? I'LL Go take a picture.