Looking for some affirmation

[hankinohio]

I am looking to build a 48 volt solar and battery system to power our refrigerators and freezers with grid backup.
I would be putting the circuits for these in a sub panel for the solar only,
I need 12 KWH a day for this panel. I figure I need;
Approximately 15 - 20 kwh of batteries
3 kW worth of solar panels
6 - 6.5 kw inverter... sized larger for possible expansion
Does this sound correct?
Would you recommend anything different?
COULD you recommend some suppliers for this system?
I was really looking at Signature Solar, but after reading some reviews, I'm a little afraid of them.
I have little knowledge of these systems and will probably need some help. SS seems to be hit or miss in the support department.

 

[Hedges]

Other suppliers include Alt E store, Current Connected, Stella Volta.

Brands include Schneider, Outback, SMA, Midnight, SolArk.

"Grid backup", you say which I take to mean you won't draw down batteries except during rare grid outages. That is like mine.
Is net metering available? If so, you can generate and use power daily, reducing utility bill (maybe, depending on rates & policies.)

AGM batteries, which I use, should last a decade with that level of infrequent usage. Cost about $6000 for 20kWh.
With only 12kWh/day, how much at night? Potentially you could get by with smaller battery. Except when it isn't sunny during the day.
LiFePO4 batteries may be similar cost, could last 16 years even with daily cycling.
Each has its own issues and benefits.

What I'm going to be installing for family and friends is 7.7kW SMA Sunny Boy Smart Energy, as grid-tie net metering. Adding batteries (high voltage) is optional, and cost would be higher compared to some 48V lithium battery solutions.

 

[houseofancients]

I am looking to build a 48 volt solar and battery system to power our refrigerators and freezers with grid backup.
I would be putting the circuits for these in a sub panel for the solar only,
I need 12 KWH a day for this panel. I figure I need;
Approximately 15 - 20 kwh of batteries
3 kW worth of solar panels
6 - 6.5 kw inverter... sized larger for possible expansion
Does this sound correct?
Would you recommend anything different?
COULD you recommend some suppliers for this system?
I was really looking at Signature Solar, but after reading some reviews, I'm a little afraid of them.
I have little knowledge of these systems and will probably need some help. SS seems to be hit or miss in the support department.

Try current connected..
@HighTechLab seems to go above and beyond for his customers

 

[DougfromdaUP]

"Grid backup", you say which I take to mean you won't draw down batteries except during rare grid outages. That is like mine.
Is net metering available? If so, you can generate and use power daily, reducing utility bill (maybe, depending on rates & policies.)

It’s funny how we look at things differently. When I read that the op would be powering his appliances with the inverter and had grid backup, I assumed he’d be using his batteries whenever the sun gets low.

 

[Hedges]

"system to power our refrigerators and freezers with grid backup"

I see what you mean. "with" grid backup, not "as" grid backup.

If net metering is available, preferable to cycle the grid than to cycle batteries.
Otherwise, the game is to guess how much to cycle batteries so you use PV as much as possible, yet have enough stored to get by if grid fails.

My Sunny Islands could operate as off-grid, but use grid "as generator" when necessary to recharge, stay above a minimum SoC.

"I would be putting the circuits for these in a sub panel for the solar only,
I need 12 KWH a day for this panel."

An inverter that performs zero-backfeed with CT at meter connection would be better; available power could go to anything in the house, so long as grid is up.

 

[hwy17]

Pick a product first, not a supplier. Then, look at the suppliers for that product.

Victron, Schneider, Outback, Sol Ark, EG4, Midnite, etc.

 

[SignatureSolarJess]

I am looking to build a 48 volt solar and battery system to power our refrigerators and freezers with grid backup.
I would be putting the circuits for these in a sub panel for the solar only,
I need 12 KWH a day for this panel. I figure I need;
Approximately 15 - 20 kwh of batteries
3 kW worth of solar panels
6 - 6.5 kw inverter... sized larger for possible expansion
Does this sound correct?
Would you recommend anything different?
COULD you recommend some suppliers for this system?
I was really looking at Signature Solar, but after reading some reviews, I'm a little afraid of them.
I have little knowledge of these systems and will probably need some help. SS seems to be hit or miss in the support department.

Hi! I had a chat with our design team manager and he has said that this will work! However he reccomends, instead of 3kw, about 5kws a panel would be better. This will charge the batteries faster, and allow your system to pull from pv input during daylight hours without dipping into your battery storage until dark. Since you're using around 12kwh per day, you would only need around 3 batteries, totalling about 12.3 kwh of battery storage. Realistically, you'd only see these batteries discharge to about 50% and your array is big enough to recharge these batteries within about 2 hours. If you'd like to reach out to me at engagement@signaturesolar.com, I'd love to get you connected with our team to assist you with your system!

 

[Mattb4]

I am looking to build a 48 volt solar and battery system to power our refrigerators and freezers with grid backup.
I would be putting the circuits for these in a sub panel for the solar only,
I need 12 KWH a day for this panel. I figure I need;
Approximately 15 - 20 kwh of batteries
3 kW worth of solar panels
6 - 6.5 kw inverter... sized larger for possible expansion
Does this sound correct?
Would you recommend anything different?
COULD you recommend some suppliers for this system?
I was really looking at Signature Solar, but after reading some reviews, I'm a little afraid of them.
I have little knowledge of these systems and will probably need some help. SS seems to be hit or miss in the support department.

Do you have to have it inspected and meet code? If so your options will be different than if you can just DIY like a UPS setup. There are many AIO (All in one) that allow off grid operation with grid as backup.

But the basics as you outlined should work. I am doing very similar at my place with 3.1PV, 10kW batt and 2-3kW AIO 120vAC inverters (not in conjunction though pulling from same battery). I am guessing that you are interested in a 240vAC split phase setup. Many of these will allow you to grow your PV since they come with multiple SCC (solar charge controllers) built in. Read some of the build threads that other Forum members have posted.

Yes there is a lot to learn but if you keep in mind W=VA you will be ahead of the game.

 

[Bluedog225]

It’s great you are doing research prior to purchase.

 

[hankinohio]

Thanks for the vendor prospects I will check them out.​

DougfromdaUP has got the idea, panels and batteries as much as possible​

I don't need inspected but I need to know what it needs to be done right
I would rather not involve the power company yet, at this point I would rather
draw some power from the grid when needed as opposed to over producing on solar.
If price was no object over production would be no problem.
Kinda thought I would start small yet meaningful till I get a handle on how to do this.
I am drawn toward EG4 products

EG4® 6500EX-48, or EG4® 6500EX-48 inverter​

EG4 LifePower4 Lithium Battery | 48V 100AH | Server Rack Battery | UL1973,​

Hyundai 300W Half-Cell Monofacial Solar Panel ( Black ) | HiA-S300HG​

I would like something that WILL NOT FEED TO THE GRID
We have a back-up portable generator that powers the house now when grid is down,
I figure to still use it during an outage, but wont have to worry about the fridges
as they will always be on solar.

This site has been a wealth of info over the last couple years,
I finally signed up gettin ready to jump in.

 

[hankinohio]

Hi! I had a chat with our design team manager and he has said that this will work! However he reccomends, instead of 3kw, about 5kws a panel would be better. This will charge the batteries faster, and allow your system to pull from pv input during daylight hours without dipping into your battery storage until dark. Since you're using around 12kwh per day, you would only need around 3 batteries, totalling about 12.3 kwh of battery storage. Realistically, you'd only see these batteries discharge to about 50% and your array is big enough to recharge these batteries within about 2 hours. If you'd like to reach out to me at engagement@signaturesolar.com, I'd love to get you connected with our team to assist you with your system!

No offense, but to be totally honest, I would be scared to death to purchase from Sig Solar at this point in time.
These systems are expensive and pretty complicated on the inside. If everything worked as should I dont think I would have any
problems with assembly/installation, but if something was not right, damaged, malfunctioned, etc, I'm afraid I would be totally lost.
I can attach black to black, red to red build a ground mount for the panels, test for voltage, etc. but if I have to open an inverter up
because something is not wired correctly... uh uh no way. I cant imagine anything in there I would know anything about or could diagnose.
Currently I dont feel confident I would get the support I may need from you guys.
To me a few hundred dollars difference would not be worth the potential lack of support in this case

 

[Steve_S]

12kWh from a "48V" LFP Battery which is actually 51.2V requires 235AH of battery + buffer.
1x 48V/100AH battery provides 5.12kWh.
With buffer, you would require at least 3 Battery Packs in Parallel, and this is for ONE DAY, and most typically, people choose to have 3 days in reserve before external generation is required. This does vary depending on region/sun exposure year-round.

Note that electric motors such as fridge/freezer/well pump/air conditioners all have heavy start surges, some far worse than others. It is not unusual to see 15-20A Draw on 120V for that start surge, especially with older appliances. This is in fact very hard on High Frequency Inverters whereas Low Frequency Inverters which can handle 3X surge are designed to have extra heavy to light loads. HF Inverters will handle such heavy surges BUT they must have larger Wattage capacity to compensate. Note that LF Inverters are much heavier & costlier (but they are also more efficient, standby/idle consumption wise).

You have expressed concerns about integrating AIO (All In Ones) and service issues. Tier-1 & 2 products are quite reliable and repairable but they come with a COST... Victron is highly recommended Tier-1 product which is well integrated with all Victron Family Products with excellent management, control & monitoring but there is a cost... but also peace of mind that it will all still be running in 10 years and still have support. Victron is more focused towards Modular/Component systems which makes them far more flexible and tailorable to specific use cases. Also it's all ULL/CSA/ETL Certified.

INSPECTIONS OR NOT !
Do you WANT INSURANCE ??? If YES then BET ON INSPECTIONS !
Power Company & Grid Connected to Feed to Grid IS FRAUGHT WITH PAINS - permits, inspections & fees upon fees upon more fees. AND then to Please Big Insurance on top... more $$$
Off-Grid (Not Feeding to Grid) but to an independent AC Main Panel, with a grid 120V circuit use ONLY for charging is the Simplest BUT insurance will still want inspections... Permits are relative to region, some want it regardless if on/off grid... It IS structural issues as well as electrical.

Personal observations...
AIO's are great & can simplify installation & maintenance BUT they have their CONS too... less power efficient, complex solar controllers (singles, doubles & high voltage), majority are High Frequency to keep them "CHEAP" as opposed to Low Frequency which are heavier & more costly.

These decisions & choices make one thing Extremely Important.
The Choice to be Penny Wise & Dollar Foolish : Buying cheaper gear and using more power & risking service/warranty/support.
Or be Dollar Wise & Penny Smart : Spend more in advance for Quality that will last much longer while being frugal over the duration.

 

[hankinohio]

Off-Grid (Not Feeding to Grid) but to an independent AC Main Panel, with a grid 120V circuit use ONLY for charging is the Simplest BUT insurance will still want inspections... Permits are relative to region, some want it regardless if on/off grid... It IS structural issues as well as electrical.

This is what I intend, the solar system ONLY powers the freezers which includes charging the batteries which only power the freezers. I would need the grid to make up for any shortfalls, but anything generated more than needed for that would just be wasted....nothing going to grid. This will be an experiment for me to learn how solar works as much as anything, and then I hope to add on later. Anything that cant be used when/if I expand can be used for a separate system for a workshop on the farm.
I have looked at Victron and as of right now would probably be my second choice, it just seemed EG4 was more user friendly, could be I have fallen for the marketing. I would rather pay more for a smaller system that lasts longer. I do have a budget, but longer life with less maintenance outweighs a larger size system. I own thousands of dollars of tools and equipment and always buy the best I can afford, If I cant afford the quality I usually wait till I can afford it. Do you feel Victron would be a better quality manufacturer than EG4? Thank you

 

[Steve_S]

EG4 is made in China by a reputable OEM on contract. They are "respectable" but NOT Tier-1 and never will be.
Honestly, Victron is the way to go, the equipment is all certified and therefore compliant for inspections, the whole interoperability - management capabilities & flexibility wins IMO.

I use Tier-1, Midnite Solar, solar Controllers, Samlex EVO Inverter/Charger (started before Victron was available here) and none of it interacts and it has to be kludged... custom software and more... IF I was building today, Pure Victron and a simplified life would result.

 

[sunshine_eggo]

Hey Hank...

You're good enough, you're smart enough, and doggone it... people like you!

-Stuart Smalley

 

[Hedges]

I do have a budget, but longer life with less maintenance outweighs a larger size system. I own thousands of dollars of tools and equipment and always buy the best I can afford, If I cant afford the quality I usually wait till I can afford it. Do you feel Victron would be a better quality manufacturer than EG4? Thank you

Here's the model I use, another tier-1:

SMA Sunny Island SI6048-US-10 Off-grid Battery Inverter/Charger. | eBay

SMA Sunny Island SI6048-US-10 Off-grid Battery Inverter/Charger. . Condition is New. Shipped with Flat Rate Freight.

www.ebay.com

That's 120V, 5750W continuous.
Expansion could be split phase or split phase and parallel.
If you would want to expand, I'd suggest buying enough up front; I'd expect it to be retired to make way for new models at some point.

You can DC couple any brand SCC if you add a battery shunt. A couple brands/models may support datacom for no shunt. Also supports AC coupled (usually requires 120/240V split phase)

25W no-load consumption. It has modes where it can run off-grid from battery, charge from grid only if too low. It can control loads based on SoC through relays.

 

[hankinohio]

LOL thanks eggo.
I guess I didn't realize EG4 was not tier 1. Guess they're out
I will dive deeper into Victron and some of the others you all have suggested.
Would it be best to stick with all the same brand of components or is it easy enough to mix and match?

 

[hankinohio]

You can DC couple any brand SCC if you add a battery shunt. A couple brands/models may support datacom for no shunt.

Right heres my biggest problem, I just learned what a shunt is a few months ago along with SCC which I still sometimes forget stands for solar charge controller. DC couple and datacom are new ones to lookup. Guessing I'll have trouble with datacom it sounds like some kind of computer hard or software, and I dont do computers too well. Another couple days of google searching. Good thing its winter. Thanks for the info.

 

[Steve_S]

Right heres my biggest problem, I just learned what a shunt is a few months ago along with SCC which I still sometimes forget stands for solar charge controller. DC couple and datacom are new ones to lookup. Guessing I'll have trouble with datacom it sounds like some kind of computer hard or software, and I dont do computers too well. Another couple days of google searching. Good thing its winter. Thanks for the info.

Simply put, it takes on average about ONE YEAR to learn about solar system, the terminology & math that goes with it for person doing general "study". 6 Months if you really wok hard at it... Somewhere around 2-3 months in, people realize that AC & DC are TWO VERY DIFFERENT ANIMALS and the damned terminology can mess you up good. Comprehending battery chemistry & understanding what exactly it does, when & how, is yet another part, which far too many have their "own notions" about.

Take your time, ask questions, KEEP NOTES ;-) and study study study.

 

[sunshine_eggo]

LOL thanks eggo.
I guess I didn't realize EG4 was not tier 1. Guess they're out
I will dive deeper into Victron and some of the others you all have suggested.
Would it be best to stick with all the same brand of components or is it easy enough to mix and match?

IMHO, I think their newer product lines like the 6000XP (lower power consumption) and the 18KPV are starting to be Tier-0.7 adjacent.