Inverter sizing

[foo1bar]

It seems everyone wants to steer me toward the grid. I'm not going to connect to the grid.

Usually people who go off-grid are doing so because that's their only choice.
In general grid-tie is the best/cheapest way to have a low/zero power bill when the grid is available and there is net metering available.

And the reason I would say you should go with a grid-tie system is that it'll be the more cost-effective option.
And all my relatives that are farmers are concerned about the cost-benefit of their decisions (because if they aren't they won't be farming anymore, they'll be selling off their land bit by bit)

SO if you want to go off-grid, be prepared to spend the $ on batteries.
But if you have a grid connection available, you can still get to a near zero electric bill ($10/month or something is probably the minimum)
AND you won't have to spend thousands on batteries every few years.

[wingshadow]

So far I haven't been able to find the lie Mike, can you give me a better idea of the MPPT system that can run a large array? I checked Morningstar and it seems 3k is their max. Am I missing something? Otherwise I am going to have to split the system up or be happy with PWM not that it is bad, I'm just searching for options. Maybe breaking it into separate units is the only way to go. I have an egg incubator which needs full a/c and accompanying 300 chick brooder to consider also. I using solar heated water for the brooder, so I limit the power to about 20 watts for a circulation pump. That only runs during a normal hatching season.

[Mike90250]

Charge controllers have several ratings. PWM or MPPT
Max input voltage
and
Max Output amps (power)

Schneider electric (600V 80A) and Morningstar (600V 60A) both make MPPT charge controllers with 600VDC input for specialty applications. about 60A DC output Pricey, but they are real and work

Midnight Solar makes several MPPT controllers in the 200 - 300VDC input range with varied hi amp outputs.

There are few reputable PWM controllers over 40A output capacity. At the large power levels, the savings in copper wire pays for the expense of the MPPT controller.

Many reputable companies (including the 3 I listed above) make 150V input, 60A output MPPT controllers. For a large 48VDC battery bank. several controllers can be required to meet the recharging demands. The largest Schneider can handle a 4,000w array on a 48V bank.

My question back to you, is what is your vendor trying to unload (sell) you ? Make and model please.
Forgive us if we ignore you till you reply with reputable (not flea bay) mfg & models (with english manuals)
Cheap shunt controllers will not deliver long term performance. You are asking about some huge loads, overnight heating and water circulation, air handlers and such,
and it's going to be very expensive to just buy the batteries, let alone the solar and electrical gear. You have to become an electrical plant engineer to run your power plant, these things are not simple when you add batteries to the mix. There is a reason we are all suggesting Grid Tie, because the battery replacement bill will blow your budget 10x over what you are paying now for cheap grid power.

Mike

gear :
Powerfab top of pole PV mount | Listeroid 6/1 w/st5 gen head | XW6048 inverter/chgr | Iota 48V/15A charger | Morningstar 60A MPPT | 48V, 800A NiFe Battery (in series)| 15, Evergreen 205w "12V" PV array on pole | Midnight ePanel | Grundfos 10 SO5-9 with 3 wire Franklin Electric motor (1/2hp 240V 1ph ) on a timer for 3 hr noontime run - Runs off PV ||

|| Midnight Classic 200 | 10, Evergreen 200w in a 160VOC array ||

|| VEC1093 12V Charger | Maha C401 aa/aaa Charger | SureSine | Sunsaver MPPT 15A

[wingshadow]

Thank you for the info on the controllers I'll find the make and models of the units I'm being offered. China is different and I'm checking out each step. The panels seemed fine but from that point on it is difficult. I'm looking at Edison nickle/iron batteries from the US for longevity. A 48v bank. What do you think? I don't like the proposed size of a single bank, and may break the farm needs into pieces. I can scale down to separate units if this setup is too large. There are other ways to cut my energy needs. I'll get solid model numbers.

[jflorey2]

I realize i can grid tie... That is not what I wish to do. That is why I have the panels, to be free of the electrical grid. Can I do this by using multiple inverters?

Sure, although you shouldn't need to. You can get to 8kw in a single inverter (Outback Radian) and they will surge to 12kW to 5 seconds, which should be enough to start anything outside of large central air conditioners. (And with a Radian, once you come to your senses, you can reconnect to the grid and reap the benefits of grid tie.)

If that's not enough you can stack them to get as much power as you like. They are about $2600 each. (Much cheaper than the batteries)

I know my basic problem is storage. My sunlight is good and I only need minimum storage if I have a way to use the power during the day and use a minimal at night.

No. You also need the battery storage to allow starting of large appliances and to run on days there is no sun.

Are you telling me solar is not the path to get off the grid? Any help is appreciated.

It's only one way to do it. Another way (far cheaper) is to use a generator. Natural gas generators work well and will run for years. If that's too much like utility power, then use propane. If you don't like propane, use a diesel generator and diesel fuel; they will last a good long time with proper care as well.

[jflorey2]

Thank you for the info on the controllers I'll find the make and models of the units I'm being offered. China is different and I'm checking out each step. The panels seemed fine but from that point on it is difficult. I'm looking at Edison nickle/iron batteries from the US for longevity.

They generally have a higher series resistance than lead-acid batteries. You'd need to oversize the bank significantly to allow for surges in demand (starting your fridge for example.)

A 48v bank. What do you think?

You'd want to go with 48 volts for a system this size. Note that that could be as many as 40 NiFe cells depending on how you configure the system.

I don't like the proposed size of a single bank, and may break the farm needs into pieces.

You will be far better off with a single system.

[Amy@altE]

If you are determined to get off the grid, you need to have your system professionally designed. This is not a system you can design yourself based on feedback from a forum. Check out the solar distributors on the forum host's site, http://www.solarreviews.com/solar-distributors/ Several of them will do the design for free if you buy the equipment from them. Stay away from "Chinese suppliers", you will end up wasting more money than you save.

[foo1bar]

If you are determined to get off the grid...

And that IMO is a big "IF"

IF you are, Amy has good advice.

If instead your goal is to just "stick it to the Power Company" - or "save $ over the next 10 years" - then you're almost certainly going to be better off with grid-tie and using that to get a near-zero electric bill.

[solar pete]

Thank you for the info on the controllers I'll find the make and models of the units I'm being offered. China is different and I'm checking out each step. The panels seemed fine but from that point on it is difficult. I'm looking at Edison nickle/iron batteries from the US for longevity. A 48v bank. What do you think? I don't like the proposed size of a single bank, and may break the farm needs into pieces. I can scale down to separate units if this setup is too large. There are other ways to cut my energy needs. I'll get solid model numbers.

Howdy wingshadow, and welcome to Solar Panel Talk. I think you need to do more reading in the off-grid section, as the first thing that needs to be done if contemplating an off-grid system is a detailed loads analysis. If you/we dont get a handle on what the system needs to deliver in kWh (kilowatt hours) per day, prefer a day and night split and max draw (what happens when all the big items get turned on at once) the system will not be designed properly and will fail. I dont want to rain on your parade but what you want to do while very doable is not easy and not cheap. That is why so many recommend a grid tied system. Cheers and good luck with it