ENER Solar panel question

[Jackpine Savage]

I just ran across some local used solar panels. They are 310w panels going for $140. I'm still putting together a small system, two 100 amp12v batteries. I have this Victron charge controller:

Victron Energy SmartSolar MPPT 150V 35 amp 12/24/36/48-Volt Solar Charge Controller​

https://www.amazon.com/gp/product/B073ZHRG9K/

Would a couple of these panels get the job done?

 

[Jackpine Savage]

Here's a little more info on the panels: Trina Solar Energy Tallmax TSM-310PD14 | EnergySage

 

[GeneSD]

What type of load do you plan to run from this system?

 

[Thinwater]

Yes. Two of those should keep your batteries charged and run a good amount while the sun is out. Once dark they will run until dead.

Hook the controllers to the battery before hooking up the solar panel to avoid ruining the controller. The power has to have somewhere to go. See if the controller needs a heat sink or similar diverter to deal with the power when the battery is charged.

 

[Thinwater]

I would get three, that way you can use all of the capacity of your controller, then get one more as back up in case something breaks one.

 

[Milkweed Host]

On ebay you can get brand new 300 watt, mono panels for $200.00, free shipping.

 

[Jackpine Savage]

What type of load do you plan to run from this system?

Ham radios, charging small batteries, and a 2000w inverter.

 

[Jackpine Savage]

Thanks Thinwater, I think I'll grab a couple.

 

[Jackpine Savage]

On ebay you can get brand new 300 watt, mono panels for $200.00, free shipping.

I have terrible luck getting stuff like this shipped. My attempt at getting a kitchen range was getting two damaged ranges and giving up.

 

[Milkweed Host]

I have terrible luck getting stuff like this shipped. My attempt at getting a kitchen range was getting two damaged ranges and giving up.

I understand.
I've seen a gradual decrease in the quality of delivers over the years.

Several years ago, I ordered 16 of the 100W mono panels. They are individually packaged
and no issues. They are still in their boxes. I only have a complete system around for that
just in case of a long term grid down situation. I don't advertise that way.

The 300W panels appeared to be a little on the big size to handle.

anyway, have fun with your project.

 

[GeneSD]

You want to ensure that if you use your batteries at night and draw them down, you have enough solar panels to charge your batteries to full and run your equipment during the day. That way the system can run 24/7 without being able to use your equipment.

 

[GeneSD]

With 840 watts of solar panels and 400 amp-hours of batteries and 4000 watt inverter, I'm skirting the limits for powering my garage appliances. It's advisable to err on the side of excess if your budget allows – go for a bit more than what you initially estimate you'll need.

 

[tech]

If you're only running a 12 volt system, you need to be careful with that little controller. For example, 3 of those panels in series (37x3=111v) will potentially exceed the mppt output (111/14=7.9 --7.9x8.3=65.57amps)
Of course, being used panels they may or may not provide advertised output...just something to think about

 

[Jackpine Savage]

You want to ensure that if you use your batteries at night and draw them down, you have enough solar panels to charge your batteries to full and run your equipment during the day. That way the system can run 24/7 without being able to use your equipment.

I think that is a challenge here in MN. We vary between 9 to 15 hours of daylight a day. We also tend to be cloudy around the shortest days. What happens when there is excess electricity generated by the panels? I assume the controller won't overcharge the batteries. Should I be prepared to add and subtract panels throughout the year? Newby questions

If you're only running a 12 volt system, you need to be careful with that little controller. For example, 3 of those panels in series (37x3=111v) will potentially exceed the mppt output (111/14=7.9 --7.9x8.3=65.57amps)
Of course, being used panels they may or may not provide advertised output...just something to think about

I am setting it up as 24 volt system. Is this the right math? (111/26=4.2 4.2x8.3=35.5)

 

[tech]

I think that is a challenge here in MN. We vary between 9 to 15 hours of daylight a day. We also tend to be cloudy around the shortest days. What happens when there is excess electricity generated by the panels? I assume the controller won't overcharge the batteries. Should I be prepared to add and subtract panels throughout the year? Newby questions



I am setting it up as 24 volt system. Is this the right math? (111/26=4.2 4.2x8.3=35.5)

It should be pretty close...actual voltage and amperages will vary plus charging inefficiencies...but close enough for government work.
Remember also that cool panels tend to put out higher voltages.

 

[Jerry]

Disagreement on the math approach - it is showing addition of amperage in addition to the voltage. When going into a series circuit the voltage adds but the amperage stays the same (if identical specs on the panels). My approach is to use the max possible voltage of the panels (open circuit - 45.5V) times 3 = 136.5V which is within nominal range of the controller. The amperage of the panels remain the same (short circuit amps = 8.85), hence potential power of three in series would be 1208 watts. Well within range on amperage, a little iffy on potential high voltage during snow covered landscape and trees reflecting additional light on a bright sunny day.

Your original idea was to use 2 panels in series which would be well within operating range of the controller. If you are looking for more power, consider getting 4 panels and run them in series/parallel arrays for nominal 24 volts and just under 18 amps, still within operating parameters of the controller. If you have extra funds available, consider doubling your battery amp hour capacity. Lead acid is the most cost effective although LiFePo4, although more expensive, has far better efficiency than lead acid. Your end use will help determine your choice. If leaning lead acid, consider 4 golf cart (traction) batteries in series which will offer just above 5 kilowatts storage. Down grade by 20% for battery life extension hence 4 kW accessible storage. If you weren't aware, traction batteries are specked at 80% discharge for their life cycle calculations, far better than the 50% spec of marine starting / deep cycle batteries.

When considering value of panels, you may wish to look into products offered by SanTan Solar. They will make a pallet to hold the panels you buy and ship it to your nearest truck terminal (you will need a pickup to get them). They are currently offering promos on freight cost.

Hope this helps, J.

 

[Txkstew]

Must be something in the air. I too suddenly got the urge to get myself a small Solar Power System built. I should have done this years ago when I was working and had plenty of disposable income. Recently, through a convergence of circumstances, I was able to pull out enough cash to buy 4 - 100 w panels from Harbor Freight. On sale they are $90. That is just the beginning.

Prices on Lithium LiFePO4 batteries have fallen substantially in the last year. I bought 4 - 100AH LiFePO4 Power Queen batteries that are down to $230 + tax, each, on their web site. I got a Renogy 3000 w inverter off Amazon for $365, and a 40 amp Charge Controller from HQST for $110.

After that, there is the Cables, Wire, Switches, Fuses, Bus Bars, Breakers, Connectors, Crimp Lugs and Tool, Terminal Blocks, Charge Meter, Solar Panel Tilt Mounts, 30 amp LiFePO4 Shore Power Battery Charger, and a New Multimeter/Volt Meter.

I bought some 12 vdc LED Light fixtures that I plan to wire to a few places around the house.

I ran my Sysyem on a full charge, a small Refrigerator 24/7 and my CPAP Machine at night, for 9 days straight before a couple of cloudy days depleted my batteries at midnight on day 9.

Tells me I need more Panels and Batteries. Probably 4 more each, which means another Charge Controller. I way underestimated what a small minimal System is. I'm getting close to $3000 invested, and going to need another $1200 + before I'm content. Who knows, I may just be getting started. I need to get a job and go back to work.

 

[Dobbin]

I think that is a challenge here in MN. We vary between 9 to 15 hours of daylight a day. We also tend to be cloudy around the shortest days. What happens when there is excess electricity generated by the panels? I assume the controller won't overcharge the batteries. Should I be prepared to add and subtract panels throughout the year? Newby questions



I am setting it up as 24 volt system. Is this the right math? (111/26=4.2 4.2x8.3=35.5)

Bannon War Room Energy Commentator Dave Walsh indicates that solar has about a 37 percent availability. I.e. a 100 watt panel will bring in about 100 x .37 x 24 = 888 watt-hours a day. (I.e. about 16 cents of electricity here in Cow Hampshire.)

Not to critique. It's 888 watt-hours a day you wouldn't have if you didn't own the panel, it can never be shut off because you didn't pay the bill (or because your politics are not correct) and your only cost is the "time value of money" you've invested.

Walsh IS a critic of "green power." But his is a world of verified payback before investment. (RT 7:29)

View: https://www.youtube.com/watch?v=yse74dAvwj4


Dobbin

 

[BH]

I've been building up 2 independent systems for my house. I bought 2 EcoFlow Delta Pro units rated for 3.6KW each. I previously bought a smaller unit rated at 720W. Am in the process of getting the solar charging up to snuff. My goal is to provide power for entertainment and refrigeration. All 3 units will grid and/or solar charge to keep the batteries up to 85%.

I agree with Jerry on the math involved with voltage / current calculations.

I am using the 720W unit for charging our phones, tablets and my laptop. Currently, this is running exclusively using grid charging and will supply device charging for almost a week w/o the grid. I do have 160W portable panel for this unit.

I'm using 1 Delta Pro (3KW usable storage) to power several lights, living room TV, cable modem, router and OTA TV antenna amplifier and OTA streaming device (Tablo). I currently have 6 x 100W panels (from Amazon, $75 ea) attached to the Delta Pro. I have the panels banked 2 in series and 3 banks in parallel, this gives me better generation when dealing with clouds, shadows and less than optimum angles. On a good sunny day, I am able to carry the load and add back a little over 20% of my battery capacity. My panels are stationary and only get properly angled sun for about an hour a day, but generates more than usage for about 5 hours a day. My next investment is a tracking panel mount, which I'm hoping will let me get 500+ watts / hour for several hours on sunny days. I have not gathered day to day power usage numbers, but it looks like I can maybe do 24 hours without the grid with the current solar configuration. My ultimate goal with the entertainment side of the house is to put in Starlink so my internet access is not dependent upon local infrastructure.

The 2nd Delta Pro is currently being used as a UPS to power an upright freezer, a small fridge and ice maker in the bar. I have some logistics to work out to get our kitchen fridge on that unit also. I anticipate needing to double the battery capacity on this unit to provide the storage I desire. No solar yet, am working out the details on solar on the other unit and will duplicate that once I get it optimized and sized properly.

I also bought an electric start 3500W pure sine generator to provide alternative charging for all 3 units for when the sun don't shine. I can select the grid charge rate on the Delta Pro up to 1800W. I can easily supply a 1200-1400W charge to both Delta Pros at the same time and provide almost total recharge in around 2 hours when the battery comes up short. They will charge from the generator and solar at the same time. Generator uses a little over a quart of gas an hour and is extremely quiet.

Best investments to date was a crimp set for making my own solar cables, a clamp on amp meter and a Kill-a-Watt power monitor (I'd really like about 2 more of the monitors). I also have a 400W portable panel that can be used if really needed. The EcoFlow stuff is expensive, but works and plugs up out of the box which makes the whole alternate power learning curve much easier.

We did have our first power outage a couple of weeks ago. We were sitting in the living room watching TV, had some lights on, and all of a sudden some of the lights went out (1 stayed on) and the TV continued to play. A couple of hours later, the other lights came back on and all 3 units topped their batteries off once the grid was back. It was a little bang for a lot of bucks, but is what I wanted.

 

[tech]

Bannon War Room Energy Commentator Dave Walsh indicates that solar has about a 37 percent availability. I.e. a 100 watt panel will bring in about 100 x .37 x 24 = 888 watt-hours a day. (I.e. about 16 cents of electricity here in Cow Hampshire.)

Um...solar panels do not collect 24 hours a day, and 37% "availability" means - what? You buy one and you only get a third? Totally senseless.
Even if he meant efficiency (typically around 20%), that is figured into the specifications...not after rating.
Anyone can comment - and many do - when they have no clue on the subject.

 

[tech]

hence potential power of three in series would be 1208 watts.

1208 watts/ 26 volts is 46 amps....still over capacity. You have to look at the entire picture.

 

[Dobbin]

Anyone can comment - and many do - when they have no clue on the subject.

Um. Owner say "availability" is the time that a generator IS available for generation at the nameplate rating. In the case of the solar, you "average" 37 percent of the time in actual sun. And rather than 100watts x 24 hours or 2400 watt-hours you get 37 percent of that - average.

Obviously you don't generate at night, and days are shorter in the winter than in summer. And there are cloudy days when you don't get full output. And solar eclipses. I think Mr. Walsh is factoring all those in to the 37 percent.

But what does he know. He's just a former executive of Mitsubishi Power Systems - with a current market cap of $64.9 Billion worldwide.

And I'm just a horse who can read and write.

Dobbin

 

[tech]

There is no way that the average solar panel installation gets over 8 hours of usable sun per day, even in the summer...perhaps the former executive was in marketing....or there was another good reason for him being "former."

 

[hiwall]

I am thinking about a second system here. I have 3000 watts on the house now and I am thinking about another similar system on the garage. The lead batteries in the house system are weakening. Walmart had some Lifepo4 batteries so I bought 4 to swap out the 8 lead batteries. I will have the lead batteries that still have maybe half life left so those could be used on the garage system. I also have a spare 4000 watt inverter and 60 amp MPPT controller on hand (spares for house).
A place about 75 miles away has 280 watt panels for $72. 12 would give me 3300 watts for $864.
It would just be a prep thing and I might just get the panels and store them with the other items for doomsday

 

[BetterLateThanNever]

There is no way that the average solar panel installation gets over 8 hours of usable sun per day, even in the summer...perhaps the former executive was in marketing....or there was another good reason for him being "former."

I've got a Delta Pro and two smart extra batteries along with three 380 watt panels and live in So. Florida.

With clear sky's I'm lucky to pull 100-150watts in the 9-10am period but it really starts cranking around 11pm till 4pm and will pull a good 800-900 watts.

Unfortunately most days are not clear but partly sunny or partly cloudy.

I never understood the difference between partly sunny or partly cloudy.

 

[Dobbin]

I never understood the difference between partly sunny or partly cloudy.

Optimist/Pessimist comparison.

Glass half full - optimist

Glass half empty - pessimist

"Partly cloudy" avoids the labeling.

Dobbin

 

[Knoxville's Joker]

THe obama era solar companies went belly up for the most part. Local distributors in major areas gobbled up the inventories and are reselling them. Your best bet is to search social media and online to see if there are local resellers or solar panel manufacturers in your area. Besides batteries solar panels are the biggest expense shipping wise.

I found a local one in my area I can get panels and charge controllers from. Then all I have to have shipped are the connectors, wiring, and adapters. Those pieces shipped are unlikely to get as damaged...

 

[bbbuddy]

I am thinking about a second system here. I have 3000 watts on the house now and I am thinking about another similar system on the garage. The lead batteries in the house system are weakening. Walmart had some Lifepo4 batteries so I bought 4 to swap out the 8 lead batteries. I will have the lead batteries that still have maybe half life left so those could be used on the garage system. I also have a spare 4000 watt inverter and 60 amp MPPT controller on hand (spares for house).
A place about 75 miles away has 280 watt panels for $72. 12 would give me 3300 watts for $864.
It would just be a prep thing and I might just get the panels and store them with the other items for doomsday

I bought panels from the guy you are talking about!

It's very easy to make your own lifepo4 batteries from cells.
I just bought 16 additional cells from 18650batterystore.com 280ah at $125 each.
They will make a 520ah battery at 24v. Double my capacity to 30 kwh.


Get a Bluetooth active balance bms to go with, and you can monitor it/turn it on and off etc from your phone.

 

[WFK]

Um...solar panels do not collect 24 hours a day, and 37% "availability" means - what? You buy one and you only get a third? Totally senseless.
Even if he meant efficiency (typically around 20%), that is figured into the specifications...not after rating.
Anyone can comment - and many do - when they have no clue on the subject.

I have commented on that before and tech is correct (Mitsubishi is not.)
(There are some other little faults mentioned in this thread, like getting 1200W out of three 300-Watt panels.)
Max rating for solar panels is perpendicular SUN (not daylight) to a panel. Non-tracking panels will never provide 8hrs of max rating per day. So scrap the .37 efficiency calculated for a 24-hr day. Many DIY have found that out painfully.
I have designed and built my own system starting before 2000 and upgraded it over the years. Retired EE.

 

[West]

I have commented on that before and tech is correct (Mitsubishi is not.)
(There are some other little faults mentioned in this thread, like getting 1200W out of three 300-Watt panels.)
Max rating for solar panels is perpendicular SUN (not daylight) to a panel. Non-tracking panels will never provide 8hrs of max rating per day. So scrap the .37 efficiency calculated for a 24-hr day. Many DIY have found that out painfully.
I have designed and built my own system starting before 2000 and upgraded it over the years. Retired EE.

It's all good though.

What would you call the bare minimum one should have for a small off the grid solar system, absolute minimum one guy could get away with. Enough to run a small 5 square foot freezer and refrigerator. Plus enough to charge batteries to run what communication and information devices at night if need be to stay informed.?

Not including the well water system, we have that worked out with only a 330 watt panel and no batteries. But do have a cistern to store water and gravity to feed the house.

 

[Knoxville's Joker]

It's all good though.

What would you call the bare minimum one should have for a small off the grid solar system, absolute minimum one guy could get away with. Enough to run a small 5 square foot freezer and refrigerator. Plus enough to charge batteries to run what communication and information devices at night if need be to stay informed.?

First get the power needs per hour of load for each device and together. Then figure out how much they need to continuously run the entire day and how much load the draw when the motors are not running and get that all averaged out. Then figure out how much daylight generation time you get. That will determine how many panels you will need when you start calculating out how much you need to run on batteries to keep them fully charged.

 

[BH]

Update on my Delta Pro progress.

Using 2 power strips, one grid connected and the other connected to Delta Pro (DP) with the Kill-A-Watt (KAW) monitoring output from the DP. My target devices for the DP currently are my cable modem, router, Tablo OTA streaming box, antenna amplifier, a 55 inch living room TV and 4 smart LED bulbs (1 each in 4 rooms). The grid connected power strip powers current devices that I have decided not to place on the DP (sound system, more lights, additional misc charging). I can rearrange grid and DP powered devices by simply moving plugs from one power strip to the other. Currently, the KAW is showing 121 hours and 7.35KW which averages 60wh (or 1440wh /day). That average has held consistent for the past 5 days.

I have the DP setup to stop charging at 85% and stop supplying power at 5% of battery capacity. That leaves me 80% usable capacity, or 2880wh. At 1440wh average daily draw, I can get 2 days of entertainment off of an 85% charge. My solar consists of 6 x 100w panels that are not specifically oriented to the path of the sun. I get output from the panels for about 6 hours a day ranging from about 50w to 400w. I'm getting replacement of about 30% (1080w) of my battery (while under load) on sunny days.

I have 3 more panels (not connected), but will be sometime next week. I plan to orient all panels to the path of the sun in 3 banks (parallel) of 3 panels (series) for a rated 60v 15a input (900w). The charge controller in the DP can handle 3 banks of 5 panels, so a 1500w array is possible (100v 15a). My initial mount will be flexible so that I can try all banks perpendicular to the mid-day sun, each bank perpendicular at different times of the day, or some other possibility. I fully expect to carry the load and replace the overnight use on totally sunny days. Typically, the TV and lights are not in use during daylight hours, so the average draw is only about 40wh during charging hours (not planning any scheduled internet downtime, 24 x 7 availability).

Will update on progress / results once the new panels are installed and the entire array re-oriented.

 

[Knoxville's Joker]

Update on my Delta Pro progress.

Using 2 power strips, one grid connected and the other connected to Delta Pro (DP) with the Kill-A-Watt (KAW) monitoring output from the DP. My target devices for the DP currently are my cable modem, router, Tablo OTA streaming box, antenna amplifier, a 55 inch living room TV and 4 smart LED bulbs (1 each in 4 rooms). The grid connected power strip powers current devices that I have decided not to place on the DP (sound system, more lights, additional misc charging). I can rearrange grid and DP powered devices by simply moving plugs from one power strip to the other. Currently, the KAW is showing 121 hours and 7.35KW which averages 60wh (or 1440wh /day). That average has held consistent for the past 5 days.

I have the DP setup to stop charging at 85% and stop supplying power at 5% of battery capacity. That leaves me 80% usable capacity, or 2880wh. At 1440wh average daily draw, I can get 2 days of entertainment off of an 85% charge. My solar consists of 6 x 100w panels that are not specifically oriented to the path of the sun. I get output from the panels for about 6 hours a day ranging from about 50w to 400w. I'm getting replacement of about 30% (1080w) of my battery (while under load) on sunny days.

I have 3 more panels (not connected), but will be sometime next week. I plan to orient all panels to the path of the sun in 3 banks (parallel) of 3 panels (series) for a rated 60v 15a input (900w). The charge controller in the DP can handle 3 banks of 5 panels, so a 1500w array is possible (100v 15a). My initial mount will be flexible so that I can try all banks perpendicular to the mid-day sun, each bank perpendicular at different times of the day, or some other possibility. I fully expect to carry the load and replace the overnight use on totally sunny days. Typically, the TV and lights are not in use during daylight hours, so the average draw is only about 40wh during charging hours (not planning any scheduled internet downtime, 24 x 7 availability).

Will update on progress / results once the new panels are installed and the entire array re-oriented.

Based on the math and to factor in a cushion factor of what you stated you would probably need a 2000 watt system minimum but a 3000 watt system(ideal) Solar systems and panels degrade over time so the more buffer you have now, the less you have to worry about over straining the system.

To put it in perspective I was looking at my well system and determined that a 4000 watt system would service the well, but, I would need to have a holding tank (one of those pallet for after hours use so I do not have the big draw of the well pump and instead just have either a gravity fed pressure system, or, a minor 12 volt pump keeping pressure on the system with minor overnight power draw.

 

[WFK]

It's all good though.

What would you call the bare minimum one should have for a small off the grid solar system, absolute minimum one guy could get away with. Enough to run a small 5 square foot freezer and refrigerator. Plus enough to charge batteries to run what communication and information devices at night if need be to stay informed.?

Not including the well water system, we have that worked out with only a 330 watt panel and no batteries. But do have a cistern to store water and gravity to feed the house.

I can't size anyone's system but my own! But I have said in earlier threads that you should start with just a refrigerator as load (approx 1.2 kWh/day.) It would show you all the potential pitfalls you could fall in with a larger system with regard to (if you misjudge!): average power consumption (kWh), peak power demand (kW), solar power rating of panels (spec versus realistic local installation, Volts, Watts, open circuit voltage, short circuit current, available output in Watts and Watt hours) and battery storage capacity (kWh) for the days you want to bridge while solar re-charge is reduced or not available.
A refrigerator is such a good test object, especially if it is "frost-free", because you really don't want to spoil food, AND it has a restarting compressor (peak currents), defrost cycle (short term heating power demand) and the average demand over days (kWh.) I learned about refrigerators when mine didn't want to start on a simple system because the battery could not handle the compressor start. That was with a new battery and would have gotten worse with a half discharged one.
Interesting loads are also submersible pumps (but there is a technology solution: ECM motors.)
My free advice for novices is: use ONLY SINUSOIDAL inverters.

 

[hiwall]

My advice is to make your new solar power system easy to change back to grid power in case you make any mistakes in sizing, etc.

 

[West]

My advice is to make your new solar power system easy to change back to grid power in case you make any mistakes in sizing, etc.

Now you tell me, after telling off the power company because I spend less in electricity than their mounthy basic service fee! Told them to go pleasure themselves....

JK

 

[Txkstew]

I went to Harbor Freight last Friday to buy another 100 w panel. It said in-stock at my store on their website. Got there, an they have none. I showed the clerk the ad, and she looked it up on her register. Nope, none in the store.

One more will give me a total of 5 100 w panels. I have them wired in parallel. They are rated at 18 vdc and 5.56 amps. I've had 4 of them charge at over 26 amps on a bright day. If I hook up a 5th, I might get around 32 amps. My charge controller is a 40 amp, and it says it can handle 25 % over.

My 4 100 ah LiFepo4 batteries are wired in parallel as well. I'd like to wire two more identical batteries, for a total of 6, in parallel as well, but it's not recommended to do that. Some YouTube guys say that is just to cover the Battery Companies ass. Others say if you put a big fuse on the battery output, or maybe it was on each battery, it would protect everything in case of a short. I'd like opinions on this, if anyone cares to share any knowledge on this scenario.

It looks like my system will be maxed out at that point, and I'll have to buy another Charge Controller. My existing one supports wiring two of the same brand together in parallel with a communication cable, making one a slave controller. I can hook up a 20 amp controller, another 40 amp one, or even a 60 amp controller. Hobotech guy has a video showing how to do it with my HSTQ controller.

This has been a fun learning experience, if not expensive. I've said it before, every time I think about this project, or just look over at it, a calm feeling comes over me.

 

[BH]

My advice is to make your new solar power system easy to change back to grid power in case you make any mistakes in sizing, etc.

That was a selling point on the Delta Pro. It has a battery reserve feature where you can pick a percent of battery remaining that when reached the unit will maintain that level using grid power. I use that to make up for the solar shortfalls as I grow the system.

I can't size anyone's system but my own! But I have said in earlier threads that you should start with just a refrigerator as load (approx 1.2 kWh/day.) It would show you all the potential pitfalls you could fall in with a larger system with regard to (if you misjudge!): average power consumption (kWh), peak power demand (kW), solar power rating of panels (spec versus realistic local installation, Volts, Watts, open circuit voltage, short circuit current, available output in Watts and Watt hours) and battery storage capacity (kWh) for the days you want to bridge while solar re-charge is reduced or not available.
A refrigerator is such a good test object, especially if it is "frost-free", because you really don't want to spoil food, AND it has a restarting compressor (peak currents), defrost cycle (short term heating power demand) and the average demand over days (kWh.) I learned about refrigerators when mine didn't want to start on a simple system because the battery could not handle the compressor start. That was with a new battery and would have gotten worse with a half discharged one.
Interesting loads are also submersible pumps (but there is a technology solution: ECM motors.)
My free advice for novices is: use ONLY SINUSOIDAL inverters.

I have a second Delta Pro that is intended for a fridge and freezer. It is currently powering the freezer in a UPS mode. The freezer is powered from the DP and the battery is maintained at 85% by the grid. Initial guesstimates look like I will need an add-on battery to manage both the fridge and freezer (7.2KW total storage, 3.6KW inverter). Once I get my entertainment system fully functional and stable, I will repeat the exercise and scale it for the refrigeration system.

I bought the 220v adapter for the pair in the hope of running my well. I think it will, but when connected with the adapter, both units disable their normal 110v outlets (nowhere does EcoFlow document this feature). Each DP will energize one leg of the 220 circuit. This would be problematic with a transfer switch and which bar in the panel the transferred circuits use. Would be very difficult to balance the load across the 2 DPs. I am rethinking my well to using a cistern / supply pump and using a 12v well pump and dedicated panel(s) with a float switch. I do have a second well for this application so I can play without impacting our everyday water.

This has been a fun learning experience, if not expensive. I've said it before, every time I think about this project, or just look over at it, a calm feeling comes over me.

I know that feeling with what I have working sofar. It has been fun AND EXPENSIVE.

 

[BH]

I have just successfully powered my internet connection, wifi network and TV behind the bar for right at 48 hours without any grid supplied power. I'm using a DP solar generator and a 900 watt (non-optimized) solar array. It is using about 40% of the battery capacity for 24 hours, so I can have 2 days of internet before charging is necessary, i.e. a day without sunshine.

Yesterday, the solar easily topped of the battery and it looks like it will again today. The Predator 3500 can provide a 2 hour complete recharge on the DP, quietly. Now to replace my cable modem and router with a Starlink receiver and I'll have internet access immune from local interruptions.