Too many options.

[markost]

Hello from central MN.
I've picked up four solar panels, that are 327 watts, 54.7 volts and 5.98 amps. I'm planning on using 4- 12v 100ah batteries with them.
I'm having trouble deciding on what controller and inverter to use with them because there are so many option to choose from. Can I
get some ideas what has worked well for others?

 

[sunshine_eggo]

First, you've already tied your hands:

1) you can't use more than 5.2kWh/day on a good day.
2) you can't use more than 5.12kWh before you need to charge.

To fully capture all your PV, you need 91A of MPPT @ 12V, 45A@24V and 23A@48V.

The size of your inverter is determined by how many simultaneous loads you want to power.

By completing the items in #1 of my signature, that gets you a good head start.

 

[markost]

You're absolutely correct on planning ahead but this is a backyard use what you've got system.
I will either be running a 36 watt bath fan or a 500 watt heater in a 8'x8' shed trying to help my honey bees make
it threw the winter. With the temperature variables of 30F to -30F I'm not going to be able satisfy every condition.
Ideally the shed will stay at 40F. Factoring in that each box of bees maintains 80F makes it more difficult to know
how the project will work out.

 

[TomC4306]

Can I
get some ideas what has worked well for others?

Every single possible iteration of batteries and solar panels has worked well for someone. You need to use the power audit resource referred in the post above and then spend some of your own time reading here on the forum.

 

[markost]

Yes, I have done some reading and studying on solar systems as I installed a 9.84kW ground mounted system
at my home in 2013. It does include an Outback inverter for some off grid use but most of the panels are grid tied.
I guess I was looking for products, ( charge controllers, inverters) that others have used for smaller systems that have worked well
for them. There are many options and I've read many reviews but I was thinking folks from this forum would have some good first
hand experience with different product lines.

 

[John Frum]

Hello from central MN.
I've picked up four solar panels, that are 327 watts, 54.7 volts and 5.98 amps.

Is that open circuit voltage and short circuit current respectively?

I'm planning on using 4- 12v 100ah batteries with them.

What chemistry?
What dc core system voltage?

 

[markost]

open circuit voltage is 64.9
Short circuit current 5.98
batteries AGM
12.6

 

[John Frum]

I've picked up four solar panels, that are 327 watts, 54.7 volts and 5.98 amps.

327 watts * 4 panels = 1308 watts
54.7VOC * 4 panels = 218.8 volts for a 4s configuration
1308 watts / 14 volts = 93.428571429 amps on the system side.

You could do 2s2p with one of these

https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-charge-controller-MPPT-150-70-up-to-150-100-VE.Can-EN.pdf

 

[AHTrimble]

Yes, I have done some reading and studying on solar systems as I installed a 9.84kW ground mounted system
at my home in 2013. It does include an Outback inverter for some off grid use but most of the panels are grid tied.
I guess I was looking for products, ( charge controllers, inverters) that others have used for smaller systems that have worked well
for them. There are many options and I've read many reviews but I was thinking folks from this forum would have some good first
hand experience with different product lines.

Victron for quality, dependability, and to sleep well when the wind blows.

 

[Pi Curio]

Too many options​

It all starts with doing the power audit, knowing what you are trying to build, and what for.

Hello from central MN.
I've picked up four solar panels, that are 327 watts, 54.7 volts and 5.98 amps. I'm planning on using 4- 12v 100ah batteries with them.
I'm having trouble deciding on what controller and inverter to use with them because there are so many option to choose from. Can I
get some ideas what has worked well for others?

Ah, 54.7V 5.98A, that gotta be those brilliantly spec 'd-out Sunpower's panels, right?

You're absolutely correct on planning ahead but this is a backyard use what you've got system.
I will either be running a 36 watt bath fan or a 500 watt heater in a 8'x8' shed trying to help my honey bees make
it threw the winter. With the temperature variables of 30F to -30F I'm not going to be able satisfy every condition.
Ideally the shed will stay at 40F. Factoring in that each box of bees maintains 80F makes it more difficult to know
how the project will work out.

Basically, you are aiming for a small solar system to power up the essentials only.

open circuit voltage is 64.9
Short circuit current 5.98
batteries AGM
12.6

So the storage will be a 12V 400Ah(4x100Ah in parallel)?


Ok, so let's take a step back here for a moment.

What are the challenges you face with your solar installation? Such as, but not limited to, winter/summer shading, available space, temperatures, and whatever? Try not to leave out relevant details.


In short, tell us more.

 

[markost]

Thanks for the impute and suggestion.
The victron MPPT 150/70 is a bit more than I was hoping to spend.
I was wondering if I went 4p with my system , could I use a victron MPPT 100/20?

 

[markost]

Yes they are Sunpower panels.
They will be my source of energy and the batteries the storage.
As I mentioned before I have an 8'x 8' shed that ideally would be kept at 40F.
I know it won't happen with the equipment I have but that is what I will be using.
So I've been looking for a charge controller and an inverter to use with the equipment I have that is not
too expensive but reliable.

 

[MisterSandals]

four solar panels, that are 327 watts,

I was wondering if I went 4p with my system , could I use a victron MPPT 100/20?

327 watts * 4 panels = 1308 watts
...
1308 watts / 14 volts = 93.428571429 amps on the system side.

1 - (20A / 93A) = .785

You would be leaving about 78% of your solar out there, unharvested, with a 20A SCC.

 

[Pi Curio]

Thanks for the impute and suggestion.
The victron MPPT 150/70 is a bit more than I was hoping to spend.
I was wondering if I went 4p with my system , could I use a victron MPPT 100/20?

Yes they are Sunpower panels.
They will be my source of energy and the batteries the storage.
As I mentioned before I have an 8'x 8' shed that ideally would be kept at 40F.
I know it won't happen with the equipment I have but that is what I will be using.
So I've been looking for a charge controller and an inverter to use with the equipment I have that is not
too expensive but reliable.

You are leaving out a heck of a lot of information.

Are you aiming for 12v 400Ah Storage, a 4x 12v 100Ah?

Is the area where you plan to install the panels always in full sunshine the whole day, winter or summer?

In any case, you only got 5Kw of storage. I won't pretend I understand AGM batteries, yet, even if you would be using the LiFePO4 chemistry, you'd really only have about 4kW available.

Are you planning to use this system to keep the Shed at 40F, 4.4C for 24/7, with the mentioned 500W heater?

Again, saying this with the best intentions, tell us more.

 

[sunshine_eggo]

Thanks for the impute and suggestion.
The victron MPPT 150/70 is a bit more than I was hoping to spend.
I was wondering if I went 4p with my system , could I use a victron MPPT 100/20?

That's only 20A * 14.4V = 288W out of your > 1200W PV. You want to waste all that?

To fully capture all your PV, you need 91A of MPPT @ 12V, 45A@24V and 23A@48V.

 

[Wakintx]

You're absolutely correct on planning ahead but this is a backyard use what you've got system.
I will either be running a 36 watt bath fan or a 500 watt heater in a 8'x8' shed trying to help my honey bees make
it threw the winter. With the temperature variables of 30F to -30F I'm not going to be able satisfy every condition.
Ideally the shed will stay at 40F. Factoring in that each box of bees maintains 80F makes it more difficult to know
how the project will work out.

Are you familiar with the bug farmer on YouTube heated hives? Actually you could get one of these small pad heaters that are used for greenhouses or that will prowse mentions goes on to RV water tanks to keep them from freezing in the winter underneath each of your hives. The bug farmer makes some super insulated hives off of plans from a guy in Maryland that I cannot remember his name, but they are called "Bee barns". Generating heat from solar is costly. As a southern beekeeper I have no experience with frigid beekeeping but there are YouTube beeks that could have good input since I always hear heating bees isn't necessary if they have sufficient honey.

12 volt heating pads watts x number of hives gives an hourly wattage. If this helps.

 

[markost]

Thanks for the info on the heated pads. I'll check it out.

Thanks to everyone else for the additional info. I believe I got part of my question answered as Victron seems to be a good option for equipment.
The other part, which one, I'll have to do some more research since I am not fully understanding how the controller works. It's definitely more complex than I was thinking. Like the controller I was thinking about was more economical but not as efficient.

Happy New Year

 

[sunshine_eggo]

Thanks for the info on the heated pads. I'll check it out.

Thanks to everyone else for the additional info. I believe I got part of my question answered as Victron seems to be a good option for equipment.
The other part, which one, I'll have to do some more research since I am not fully understanding how the controller works. It's definitely more complex than I was thinking.

It's not. It's just a smart DC-DC converter that can vary its output up to a maximum current. It evaluates how the voltage responds to the current draw and finds the point where Volts * Amps = max.

Like the controller I was thinking about was more economical but not as efficient.

If you're referring to the 100/20, your statement isn't correct. It's as efficient as any Victron controller. The issue with your system is that you have 12V batteries and 1308W of solar. This requires the aforementioned 91A of charging current. This also means you may toast your AGM batteries unless you have about 455Ah of AGM batteries as they can only handle a charge about 20% of their capacity.

It's important to understand the numbers. 100/20. The 100 refers to the INPUT voltage of the array - must not exceed 100V (and must have some headroom to ensure you don't go over 100V in cold weather). The 20 refers to the OUTPUT current of the charger - 20A.

You can't rearrange your array to get more than 20A out of the controller, 2S2P, 4S, 4P are all the same 1308W of power.

If you went to a 48V system, that 100/20 controller could handle 20A * 57.6V = 1152W - which would capture what your array outputs the vast majority of the time.

https://www.victronenergy.com/upload/documents/Datasheet-SmartSolar-charge-controller-MPPT-75-10,-75-15,-100-15,-100-20_48V-EN.pdf

 

[markost]

So what I hear you saying is; no matter how I wire my panels to the controller, it will always produce about 1152 watts, or they need to be in parallel to maintain the 54.6v.
If I wire my 4 batteries in series, it will be a 48v system and the 100/20 controller can handle that.
Am I getting closer or still missing something?

 

[sunshine_eggo]

So what I hear you saying is; no matter how I wire my panels to the controller, it will always produce about 1152 watts,

Essentially correct; however, configurations have implications. 4S would be ~260V, and that would destroy most controllers. 2S would be 130V and too high for a 100/20, so 4P is really your only option.

There is also the issue of the PV input current limit of 20A. It appears your panels have a 6A Isc value, and that would put your PV input current limit at 24A vs. 20A rated. In many cases, this is considered a pliable limit. It won't damager the controller configuring it this way, but if you inadvertently connect panels backwards, the reverse polarity protection may be defeated.

or they need to be in parallel to maintain the 54.6v.

On a 100/20, yes. Also worth noting that 54.6V, if that's the Vmp of the panels, may prove to be inefficient at charging a 48V battery at peak voltage.

If I wire my 4 batteries in series, it will be a 48v system and the 100/20 controller can handle that.

with the exception mentioned immediately above.

Am I getting closer or still missing something?

I think you're getting there.

As we work through these numbers, a 2S2P array on a 150/35 controller would be far more optimal. Yes. That controller is about 2X the 100/20, but it's a much better option. Your panels a somewhat odd-sized.