Hey everyone, another new idiot to solar mastery

[The new solar idiot]

Amazon.com description actually says

"The inverter is a dual photovoltaic input and dual AC output 24V DC to 220V/230V/240V AC pure sine wave solar inverter"

But single phase 240V is not split phase 240V.
If you want to operate appliances that are standard in the US, you need split phase 120V-240V.

Single phase 240V is used in Europe.

In US, it's options 1 and 3 from the diagram below.

View attachment 206930

I haven't received it yet and its strange amazon is selling this like is normal to US. I will return but a similar like unit for reference would be great as my 2 hours dumpster diving in reviews is like 2 seconds to someone with knowledge thanks

 

[sunshine_eggo]

Ok I didnt notice anything about EU but I understand what you are saying. So If I find a similar unit that is 110/120 would it be ok? or do you have any suggestions in the sub $300 range like this one?

Unfortunately, 120V single phase inverters are always more expensive than 230V (EU) single phase. I can only imagine that those markets are larger for those manufacturers, so they benefit from economy of scale. I have this:

https://www.amazon.com/PowMr-Inverter-Off-Grid-Controller-Lead-Acid/dp/B0B9ZMZ2YY

That I picked up on black friday for just over $400, and it's price is all over the place. IIRC, this is a SRNE clone which is a Voltronics clone. Growatt and MPP solar have similar units, but you're going to pay $100-200 more than the one you linked.

 

[CaliSunHarvester]

I haven't received it yet and its strange amazon is selling this like is normal to US. I will return but a similar like unit for reference would be great as my 2 hours dumpster diving in reviews is like 2 seconds to someone with knowledge thanks

If you don’t need to power 240V appliances, which is probably a stretch for a 24V system, something like this would work:

https://www.amazon.com/Inverter-110...m-Generator/dp/B08R3MSXTG/ref=mp_s_a_1_1_sspa

 

[The new solar idiot]

Unfortunately, 120V single phase inverters are always more expensive than 230V (EU) single phase. I can only imagine that those markets are larger for those manufacturers, so they benefit from economy of scale. I have this:

https://www.amazon.com/PowMr-Inverter-Off-Grid-Controller-Lead-Acid/dp/B0B9ZMZ2YY

That I picked up on black friday for just over $400, and it's price is all over the place. IIRC, this is a SRNE clone which is a Voltronics clone. Growatt and MPP solar have similar units, but you're going to pay $100-200 more than the one you linked.

I am ok with that as long as its a quality unit that has some lifespan given the whole solar thing is like a bank account that pays back if you will. Obviously nothing up front but long term. And again im not spending 30k on a system like most people often get conned into but low budget slow payback is ok.

 

[Hedges]

care to elaborate? thanks

Live Ground Shocked 5 Year Old

Hi All, I have a shipping container that I’m building an off grid system for. I have 2, Growatt SPF 5000 ES inverters purchased from Alibaba connected in parallel and a Growatt auto transformer that’s powering an outlet that’s jumping another outlet that’s in a metal box screwed into the...

diysolarforum.com

 

[Hedges]

If you don’t need to power 240V appliances, which is probably a stretch for a 24V system, something like this would work:

https://www.amazon.com/Inverter-110...m-Generator/dp/B08R3MSXTG/ref=mp_s_a_1_1_sspa

Consider a 48V system, which is pretty mainstream by now.
Unless this will always be a very small system.

 

[Gromike2]

I think the barrier to doing your own solar electric is the electrical code, wherever you are. If you are DIY and you need to comply to the latest NEC code you are sh*t out of luck unless you are a serious solar electric junkie. The learning curve has become too steep for DIY.

 

[ksmithaz1]

For sanity I'd get a EG4 6000XP or similar, (Growatt, whatever) and either cobble together or get a modest 48V battery setup, 5KWHish. Then grab an Openevse (https://www.openevse.com) EVSE, all of which is going to get you upwards of $3K. Probably more than you wanted to spend, but will allow you to scale up and expand trivially. I think they (openevse) have the NACS cables back in stock again, it takes either NACS or J1772. The EVSE is a little pricey, but has a full api and web interface that allows connectivity via wifi, and you can adjust charging rates manually, via schedule, or thru a number of api methods. It supports charging rates down to 6A. I poll mine with a php script and adjust the rate based on my SOC and TOD on a sliding scale. https://openevse.stoplight.io/docs/openevse-wifi-v4/6e3b6e2f1b976-open-evse-wi-fi-for-esp-32

The batteries would just act as a buffer, since your solar output can be erratic. For starters you don't have to go overboard, just find a charging rate that works. For example start charging the car when the battery is 100% and charge at a rate that tries to keep the battery draining slowly bleeding out the batter to say 10%, when the sun is gone. Then set some schedule to kick in that does something similar.

Go ahead and pick up a few more panels, you will want them. The trick is going to be to stay plugged in whenever you are at home, and ultimately you are going to want to integrate with the inverter in some way, and get up to ~3KW of output. Thus in around 4 hours you can dump 10 or so KWH into the car. I have found this to be the most challenging aspect of my solar goals. An EV just sucks it down. So today, the Kona came home at 1320, got plugged in not much else going on, PV fell off when the batteries hit 100%, basically it charged for 2 hours at 7600W, which re-filled from the 40 mile commute direct from solar. I just keep them topped up, this was around 15KWH. I you can get to 3KW for 5 hours you are basically talking maybe 1/6th of a full charge, which is significant enough, depending on how much you drive. The ROI will not be very good in most cases.

 

[The new solar idiot]

Ok so here is what I settled with. I took a couple of your suggestions and bought this 24v 110v hybrid inverter https://amzn.to/3TJrLh7. I am going to purchase 3 12v 100a/h batteries(not sure which ones yet). The 3rd is a backup in case I lose one electrically etc. I am sending back the other inverter that I bought as per your request. So the main question I have and probably one of the final ones hopefully is can I run all my panels in series? If so should I stick with six or should I get the other two to make eight? from what I read if I run in parallel, I need a bunch of fuses which is bad and expensive and draws power which obviously I don't want. When I tested the panels in the sun they pulled about 33 volts each. six panels at 240 watts/33v should be something like 1440watts/198v and 8 at 1920w/264v. Obviously less sun is going to mean less wattage/voltage but is this okay to run all in series or should I run them in two series and parallel at the end to target closer to my goal ac output? I don't know if there's a best practice here this is the part that I don't know.

Also why I appreciate everybody's help keep in mind this is just a small build I will have a larger project in the future sometime at a different location so this is simply to learn not a whole home off-grid replacement. I'm not anticipating saving a million dollars here If I'm lucky it may pay itself off in 4 years which isn't very exciting but rather interesting to learn about.

 

[CaliSunHarvester]

So the main question I have and probably one of the final ones hopefully is can I run all my panels in series?

You have 6 panels, 30V each 7.87A each.
The referenced charger allows up to 450V input, 6 * 30V = 180V is well below the maximum.
If I understand the description right, the max input is 13A. So if you were to parallel the panels e.g. 3s2p, you would possibly not be able to pull the theoretically full 16A.

So, not only you can, you *have* to run them all in series.

That's a good thing if all 6 panels have the same amount of sun/ shade situation.

More panels in one string = higher voltage. Higher voltage means a % wise smaller voltage drop, and you can use slightly cheaper wire than if you would run things in parallel with higher currents.

should I get the other two to make eight?

8 * 30V = 240V , still far below the unit's 450V limit.
Without knowing how cold it gets in your area, I think you can safely have 10 or 12 panels which would be 300V or 360V.

 

[The new solar idiot]

You have 6 panels, 30V each 7.87A each.
The referenced charger allows up to 450V input, 6 * 30V = 180V is well below the maximum.
If I understand the description right, the max input is 13A. So if you were to parallel the panels e.g. 3s2p, you would possibly not be able to pull the theoretically full 16A.

So, not only you can, you *have* to run them all in series.

That's a good thing if all 6 panels have the same amount of sun/ shade situation.

More panels in one string = higher voltage. Higher voltage means a % wise smaller voltage drop, and you can use slightly cheaper wire than if you would run things in parallel with higher currents.



8 * 30V = 240V , still far below the unit's 450V limit.
Without knowing how cold it gets in your area, I think you can safely have 10 or 12 panels which would be 300V or 360V.

Okay thank you that is great information so as of right now the only thing I'm powering is a 5,000 gallon per hour pump in my pond which is roughly 294 watts so I should have plenty to go and I'm also considering running again my garage lights which are right around the 500 to 600 w range so I should be good to go theoretically I guess now am I good with three batteries it seems like almost overkill considering I have sun during the summer from 6:00 a.m. to 8:00 p.m. with no interruptions. Another member has commented in saying that if I was to buy deep cycle batteries they would only be used for starting power in this situation so I would imagine I'm good if I buy some deep cycle marine batteries that are roughly 100 amps per hour about $75-90 a piece. Sound right?

 

[CaliSunHarvester]

I'm good if I buy some deep cycle marine batteries that are roughly 100 amps per hour about $75-90 a piece. Sound right

Above my pay grade

 

[The new solar idiot]

Above my pay grade

Well dang me me to that level . I like cheap

 

[pollenface]

I come up with the same number, and it's qualified by "when everything is perfect"...

Taking all inefficiencies into account, I hypothesized that I might need 2.7kw pv to supply 1.5kw charging power to my EV

The most cost effective way to use PV panels is with grid-tie inverter, and a net-metering plan with your utility. Look up if they allow that and what the deal (and utility rates) would be.

We charge ours with grid-tied solar during sunlight hours about 90% of time. Every now and then have to do an "overnighter"

 

[sunshine_eggo]

Consider that you only have 50Ah usable without shortening their battery lives.

Quality AGM batteries are good to about 1000-1200 cycles to 50% depth of discharge if they are properly charged and floated.

Quality FLA batteries are good to 2000-3000 cycles to 50% depth of discharge if you maintain them like you have OCD. If you maintain them poorly, AGM will outlast them.

AGM: $200 for 50Ah 1100 times. That's 50Ah * 12V * 1100 = 660,000Wh of energy delivered. $0.30/kWh
FLA: $100 for 50Ah 1500 times. That's 50Ah * 12V * 2500 = 1,500,000Wh of energy delivered. $0.06/kWh
LFP: $300 for 80Ah 4000 times. That 80Ah * 12.8V * 4000 = 4,096,000Wh of energy delivered. $0.07/kWh

So, while LFP may feel more expensive, it's BARELY more expensive than FLA and much cheaper than AGM.

 

[ksmithaz1]

Also why I appreciate everybody's help keep in mind this is just a small build I will have a larger project in the future sometime at a different location so this is simply to learn not a whole home off-grid replacement. I'm not anticipating saving a million dollars here If I'm lucky it may pay itself off in 4 years which isn't very exciting but rather interesting to learn about.

Be mindful, I don't really think you are going to get much of an ROI, and outside the panels these purchases are not going to scale, thus I'd buy only TWO batteries. If you move up you will likely be throwing new money after experience earning money. In this scenario, having a spare 12v laying around is pretty much pointless if this is going to charge cars. Worst case is if something goes south down the road, you wait a few days for a less expensive battery or batteries, and you can't charge with solar for a short time.

I would strongly suggest a 48v system, and frankly something like the PowrMr 220v setup (Below) worked for me/will work just fine if wired correctly. I had FIVE(5) of them in parallel, (with a 100A/40A Auto-Transformer) and while they fell over starting my 4T A/C they had no problem at all charging the car, which is what I pre-tested with. Who knew the A/C that pulled 20A was worse than the EVSE that pulled 32A? If you are willing to buy THREE batteries, get FOUR, and a small inexpensive 220v 48v system. As time passes you can add an auto transformer (The Victron is not that expensive), if you want split phase output for playing around. You can also then simply add on to what you have, more panels, more batteries, and replace the inverter with something more robust. The batteries are going to set you back the most, I'd downsize the batteries if you need to save cash


160*4 = 640 for 48v@50AH, 2400W, mind your output amps.

This unit is 220-240v (settable), 240*6 = 1440W, should be kind of a minimum for car charging, would be great with about 2000W of panels, and





So 640 + 450 = $1100

Get a low end programmable EVSE, swap the cord, or you should already have the J1772 to Tesla, but ymmv







So $1100 + 200 = $1300 all in

That seems very doable, and very scalable with extra panels. I think it takes up to 500v on the MPPT.

 

[sunshine_eggo]

You sure about the EU inverter?

 

[Hedges]

What, is Tesla not compatible with EU?

 

[The new solar idiot]

Consider that you only have 50Ah usable without shortening their battery lives.

Quality AGM batteries are good to about 1000-1200 cycles to 50% depth of discharge if they are properly charged and floated.

Quality FLA batteries are good to 2000-3000 cycles to 50% depth of discharge if you maintain them like you have OCD. If you maintain them poorly, AGM will outlast them.

AGM: $200 for 50Ah 1100 times. That's 50Ah * 12V * 1100 = 660,000Wh of energy delivered. $0.30/kWh
FLA: $100 for 50Ah 1500 times. That's 50Ah * 12V * 2500 = 1,500,000Wh of energy delivered. $0.06/kWh
LFP: $300 for 80Ah 4000 times. That 80Ah * 12.8V * 4000 = 4,096,000Wh of energy delivered. $0.07/kWh

So, while LFP may feel more expensive, it's BARELY more expensive than FLA and much cheaper than AGM.

More great info. Bottom line is best deal FLA w/OCD in my crawl space....eerf but LFP overall win long term. Reality is this is a 5-8 yr system I am guessing as I dont actually know the age of the panels and with FLA My Break even is about 48 months so not sure LFP is in my budget unless someone has the hookup

 

[The new solar idiot]

Be mindful, I don't really think you are going to get much of an ROI, and outside the panels these purchases are not going to scale, thus I'd buy only TWO batteries. If you move up you will likely be throwing new money after experience earning money. In this scenario, having a spare 12v laying around is pretty much pointless if this is going to charge cars. Worst case is if something goes south down the road, you wait a few days for a less expensive battery or batteries, and you can't charge with solar for a short time.

I would strongly suggest a 48v system, and frankly something like the PowrMr 220v setup (Below) worked for me/will work just fine if wired correctly. I had FIVE(5) of them in parallel, (with a 100A/40A Auto-Transformer) and while they fell over starting my 4T A/C they had no problem at all charging the car, which is what I pre-tested with. Who knew the A/C that pulled 20A was worse than the EVSE that pulled 32A? If you are willing to buy THREE batteries, get FOUR, and a small inexpensive 220v 48v system. As time passes you can add an auto transformer (The Victron is not that expensive), if you want split phase output for playing around. You can also then simply add on to what you have, more panels, more batteries, and replace the inverter with something more robust. The batteries are going to set you back the most, I'd downsize the batteries if you need to save cash

View attachment 207137
160*4 = 640 for 48v@50AH, 2400W, mind your output amps.

This unit is 220-240v (settable), 240*6 = 1440W, should be kind of a minimum for car charging, would be great with about 2000W of panels, and


View attachment 207134


So 640 + 450 = $1100

Get a low end programmable EVSE, swap the cord, or you should already have the J1772 to Tesla, but ymmv

View attachment 207140


View attachment 207141


So $1100 + 200 = $1300 all in

That seems very doable, and very scalable with extra panels. I think it takes up to 500v on the MPPT.

ok so if I go this route, am I screwed if I decide EV charging isn't cutting it since it doesn't seem to offer 110v? Amazon is going to hate me