Need Advice

[sturk]

I am starting a new off grid system in the UP of Michigan. I did an energy audit and came up with 5648 Watts an hour if everything is on. The biggest load is the well pump, 26.6 amps on start 6,384 Watts. Run Amps 7.8 or 1,872 Watts. The rest of the load is for washer and propane dryer, chest freezer, port ice maker, led lights, tv, ceiling fan, Dish TV, WeBoost, C-Pap, and cell phone charger. We don't ever expect to have all of this running at once.
My question is that I am looking at 2 LVX6048 with 40 solar panels 250 Watts each. I will also be adding lights and plugs for a pole barn. Is this overkill?

I have not decided on batteries yet but the extreme cold is is making me look at AGM or something similar. Use of camp is mainly May-November but there may be occasional winter use. Any advice would be appreciated.

 

[Hedges]

AGM is lower maintenance, FLA can be longer life. Oversized forklift or Rolls-Surette people report 20 year life from.
You want the system to regulate charge current to optimum for the battery. For my AGM that is 0.2C

Excess PV is good, makes up for bad sun days and lets system maintain target charge current. PV is 1/10th the cost of batteries.

26.6 amps - at 120V or 240V?

The best, most robust off-grid system wouldn't be a low-price high frequency inverter. It would be Sunny Island, Outback, Schneider, etc.
PV panels can be bought used or surplus, but top quality should hold up better than cheapest or degraded bad old ones.

Have a budget?

Figured out how many usable kWh storage you need?

 

[sturk]

the well pump is 3/4 hp 240 v as far as storage I have been looking at 12v 200ah 12 to 16 of them in 4s3or 4p

 

[Hedges]

240V x 26.6A = 6.4kW surge.
An inverter (or stacked pair) delivering 240V probably works better than 120V with step-up transformer, but transformer could be OK if sized for that current. e.g. a single SMA Sunny Island 6048US, 120V, with a 120/240V auto- or isolation transformer.

Sunny Island work with DC coupling (use a battery shunt or data interface to Midnight Classic if compatible versions & protocol still available), but I prefer AC coupled. That lets most power go direct to loads, and Sunny Island regulated battery charge current to target rate (which it can't do DC coupled.) During the day you get the AC output of GT PV Sunny Boy, supplemented by AC from battery and Sunny Island if needed. 10 kW PV panels can fit one 6kW or 7kW GT PV inverter if multiple angles. Or, two Sunny Boys for up to 12kW of AC from PV can be managed by one Sunny Island. You might get a new old stock Sunny Island and Sunny Boy for $4k to $5k. You can find a used transformer for $300 to $1k.

https://files.sma.de/downloads/SI6048US-DS-en-28.pdf

Batteries, fewer but larger is usually recommended.
2p or 4p, there are clever ways to match resistance and current draw. 3p, just need matched wires to a busbar.

I have SunXtender 8x 6V 405 Ah, cost $5000 two years ago.
You can get 6V or 2V for larger cells and still a battery that you can manhandle with a dolly.
Some other manufacturers of FLA and/or AGM also have 4V batteries, I think. (or maybe that was 8V)

Sun Xtender Solar Batteries - Photovoltaic Battery

The Sun Xtender Battery line consists of specialty lead-acid solar, photovoltaic batteries, and renewable energy storage batteries manufactured by Concorde Battery Corporation.

sunxtender.com

 

[sturk]

thanks for the information all advice helpful

 

[LazyDragon]

As with most things in life, budget is key. If you want to build out a big system as a property upgrade, that's fine.
However, that's a lot of solar spend for a location you plan to leave idle from December to April. If you were staying there over the winter, all those extra panels would be great. I would cut the panels from 40 to 10 or 20. Buy a nice, quiet inverter generator to make up the difference when needed. You will probably need a generator option no matter how many panels you have anyway.
That well pump is a moose. My 1/2 hp 120V pump only uses 900W running. Do you have a single well pump that is also your pressure pump, or a storage tank and a separate pressure pump? I have separate, and I have my well pump fill the tank during early morning hours, so the usage never interferes with any other loads. For you, its all about that pump. Use a single AiO that supports 240v split phase, IF that inverter can handle the surge when your pump kicks on. Build it and see!
Another advantage of a single inverter (in addition to cost and convenience) is portability. When you leave for the winter, you can take your generator and inverter with you. 2 of your high price items are safe from theft. Batteries could also come depending on design and weight. Consider lipo instead of the heavy old stuff. The server rack batteries might give you another slightly more portable option. Pull them out when you leave. Now the only thing exposed to trouble are the panels themselves.

 

[rhino]

If your only 240V load is the well pump you might consider looking into replacing it with a Grundfos 120V variety. I did this to avoid needing my system to support 240V at the time. They are also extremely efficient and don't have the surge current.

 

[sturk]

thanks for the reply we new live here 6months a year we have been running a generator and small battery and inverter for a few years switching back and forth gets to be a pain the well p

 

[sturk]

sorry working off a phone but the pump is a pain 108 feet down then 20 feet above the well head

 

[sturk]

hi rhion looked at it after i had the well installed was not sure it wood work for us

 

[nogridhome]

The many years I lived in Michigan I happen to know that the wind is always blowing. I would look to incorporate a small (or larger) windmill into the game. Mighigan has a bright summer but a very dark winter. In the winter, these panels will be covered with fresh snow daily. Mount them in a place or fashion where you will be able to clean them off. I like the plan for two inverters as there is some level of redundancy. I build everything with redundancy and backups in the plan. Someday one of these devices will fail. Where will you be when that happens? Have a plan (and a spare).
My entire system is built on redundancy.
All about panel mounting:

All about the power plant:

Never forget that the owner of this site (Will Prowse) has like 1,000 brilliant videos and IS THE FINAL WORD on all things solar.
Review his vid's you will learn a lot. Plus you can join his trillions of subscribers on YouTube to get the latest updates.

 

[sturk]

thanks for the reply I have look at wind but that would be a project down the road wife and I started this 3 years ago solar is next hopefully we'll get it done this year i like your shed we are doing something like that but how do you keep your batteries warm

 

[nogridhome]

Excellent question friend, I was concerned about that way back when I got started. I never did anything about it. It never seemed to matter so I forgot about it. So to answer your question directly, I use them, this keeps them warm enough.
When using or charging the battery it naturally generates its own heat. Mine are mounted on a piece of 2" stryofoam. They are in the shed that protects them quite a bit as the chargers and inverter generate heat. If I was in Michigan and not in N.C. I might have to address this but in my case it is irrelevant (so far). I have had no issues and our low was 17 degrees this year. The batteries in these systems are always being charged or discharged so they will always help keep themselves warm. Even when you are using 0 watts the inverter is drawing watts just to have the system on and ready to deliver power. I really like my generator, recommend westinghouse dual fuel, I piped it to my propane tank so I never have to mess with liquid fuels. It will run as long as my 500 gal tank has gas. Comes with remote control too. Models are always changing. Home Depot: about 10kw, dual fuel. All the Best!

 

[JohnnyC]

240V x 26.6A = 6.4kW surge.
An inverter (or stacked pair) delivering 240V probably works better than 120V with step-up transformer, but transformer could be OK if sized for that current. e.g. a single SMA Sunny Island 6048US, 120V, with a 120/240V auto- or isolation transformer.

Sunny Island work with DC coupling (use a battery shunt or data interface to Midnight Classic if compatible versions & protocol still available), but I prefer AC coupled. That lets most power go direct to loads, and Sunny Island regulated battery charge current to target rate (which it can't do DC coupled.) During the day you get the AC output of GT PV Sunny Boy, supplemented by AC from battery and Sunny Island if needed. 10 kW PV panels can fit one 6kW or 7kW GT PV inverter if multiple angles. Or, two Sunny Boys for up to 12kW of AC from PV can be managed by one Sunny Island. You might get a new old stock Sunny Island and Sunny Boy for $4k to $5k. You can find a used transformer for $300 to $1k.

https://files.sma.de/downloads/SI6048US-DS-en-28.pdf

Batteries, fewer but larger is usually recommended.
2p or 4p, there are clever ways to match resistance and current draw. 3p, just need matched wires to a busbar.

I have SunXtender 8x 6V 405 Ah, cost $5000 two years ago.
You can get 6V or 2V for larger cells and still a battery that you can manhandle with a dolly.
Some other manufacturers of FLA and/or AGM also have 4V batteries, I think. (or maybe that was 8V)

Sun Xtender Solar Batteries - Photovoltaic Battery

The Sun Xtender Battery line consists of specialty lead-acid solar, photovoltaic batteries, and renewable energy storage batteries manufactured by Concorde Battery Corporation.

sunxtender.com

You can install a soft start control on almost any pump... should look into this with your local supplier. It being for electrical stuff... pool pump... etc. This would reduce your inrush current drawn by the pump motor at start to a value suitable for your implementation.