Inverter/charge controller.

[Clinton Earl]

Hello.
I'm brand new here and to solar systems.
I was recently fortunate to get my hands on 14 Jinko bifacial 460w panels, which totals 6 440w. I need to find an inverter/ charge controller capable of handling this, for a 24v system at a reasonable price! Any helpful advice welcomed. Thanks in advance!

 

[pvgirl]

Knowing the panel model number, a spec sheet, or at least a photo of the spec labels would be needed to size an charge controller. Also details on how the panels will be installed, all installed together, facing one direction, with minimal shading, or some thing more complicated.

 

[Q-Dog]

You could enter your panel specifications into this calculator to get an idea of how big a charge controller you need.

MPPT Calculator - Victron Energy

MPPT Calculator - Victron Energy

www.victronenergy.com

 

[Clinton Earl]

Knowing the panel model number, a spec sheet, or at least a photo of the spec labels would be needed to size an charge controller. Also details on how the panels will be installed, all installed together, facing one direction, with minimal shading, or some thing more complicated.

 

[Clinton Earl]

I don't know how I should put the panels together! Can I just attach all 14 panels together in series, and just have a pos and neg MC 4 going to the inverter/controller, or is there a better way? Thanks!

 

[MisterSandals]

Can I just attach all 14 panels together in series

51.9Voc x 14 = 726V array.
SCCs that handle this voltage are very rare and very expensive.

If you connect 7 in series, twice, and connect them in parallel (7S2P) you will find quite a few solutions.

What is your budget and reliability requirement?

 

[pvgirl]

12 in series is going to way to much voltage for any charger or inverter. That is a large system for 24volts, do you have an existing system you are integrating with? Upgrading to 48 volts would give many more options.

 

[Clinton Earl]

51.9Voc x 14 = 726V array.
SCCs that handle this voltage are very rare and very expensive.

If you connect 7 in series, twice, and connect them in parallel (7S2P) you will find quite a few solutions.

What is your budget and reliability requirement?

I really don't understand all the numbers or what they mean, or how to do the calculations, because I didn't do mathematics in high school. But if you tell me this is what you need, and this is how to put it together, then I can do it! I learned just a few weeks ago what a MC 4 is!
Thanks!

 

[MisterSandals]

or how to do the calculations,

Ok, i will try to explain.
When you connect panels in series, the voltages of the panels are added. So having all 14 panels in series, the resulting voltage is too high.
If you make 2 difference strings of 7 panels in series, the resulting voltage is very good for an array.
You would then combine these 2 strings with a MC4 Y connector before connecting to a solar controller.

This is the MC4 Y connector pair:

https://www.amazon.com/BougeRV-Connectors-Branch-Parallel-Adapter/dp/B0753X68PS/

This is likely the best way to configure your array.

Now on to a solar charge controller (SCC). What is your budget and how reliable does it need to be?
Are you keeping beer cold or is it for the mother in laws oxygen supply?

 

[Clinton Earl]

Ok, i will try to explain.
When you connect panels in series, the voltages of the panels are added. So having all 14 panels in series, the resulting voltage is too high.
If you make 2 difference strings of 7 panels in series, the resulting voltage is very good for an array.
You would then combine these 2 strings with a MC4 Y connector before connecting to a solar controller.

This is the MC4 Y connector pair:

https://www.amazon.com/BougeRV-Connectors-Branch-Parallel-Adapter/dp/B0753X68PS/

This is likely the best way to configure your array.

Now on to a solar charge controller (SCC). What is your budget and how reliable does it need to be?
Are you keeping beer cold or is it for the mother in laws oxygen supply?

Can I run the 2 strings of 7 panels on 24v or do I have to go to 48v?
My system needs to be reliable with enough storage to get me through a Canadian winter storm, as I am completely off grid, so looking for good quality at a reasonable price! Not looking to pay a premium because it's a brand name!
Thanks for your advice thus far, very helpful!

 

[MisterSandals]

Can I run the 2 strings of 7 panels on 24v or do I have to go to 48v?

You can get an SCC that works with whatever battery voltage you want. The MPPT functionality takes the array voltage and lowers it to you preferred battery voltage.

14 panels x 460W = 6440W total

6640W / 28V battery charging = 230A charging (this is a LOT!)

What are you planning on powering, an entire house?
If you have a lot of appliances, you should strongly consider getting a 48V battery to make the wiring and fusing reasonable because the amps will be much lower.

Do you have a battery in mind? Budget?

 

[pvgirl]

To stay at 24volts you are going to need 3-4 80-100amp charge controllers and the panels split among them. In groups of no more then 3 series and 2 parallel.

 

[Clinton Earl]

You can get an SCC that works with whatever battery voltage you want. The MPPT functionality takes the array voltage and lowers it to you preferred battery voltage.

14 panels x 460W = 6440W total

6640W / 28V battery charging = 230A charging (this is a LOT!)

What are you planning on powering, an entire house?
If you have a lot of appliances, you should strongly consider getting a 48V battery to make the wiring and fusing reasonable because the amps will be much lower.

Do you have a battery in mind? Budget?

I am completely new to solar, so I have no idea what the differences are between the various batteries. I plan to run my camper, an extra freezer, coffee maker, an extra heater or 2 , and a few more appliances, with no connection to the grid soI need storage capacity for about 3 to 5 days incase of a winter storm. For this reason I'm looking for batteries in the lower price range.
Thank you for your insights!?

 

[MisterSandals]

I plan to run my camper, an extra freezer, coffee maker, an extra heater or 2 , and a few more appliances, with no connection to the grid soI need storage capacity for about 3 to 5 days

Do you know how many watts these appliances use?
What does "run my camper" mean? Couple lights? A tv for 10 hours? Power a refrigerator, run A/C, ...

You need to add your power needs in order to properly size a battery, charger and inverter.

6400W of solar is quite a lot of power. You can build a very nice system with quality components for $10k to $30k.

 

[Clinton Earl]

Do you know how many watts these appliances use?
What does "run my camper" mean? Couple lights? A tv for 10 hours? Power a refrigerator, run A/C, ...

You need to add your power needs in order to properly size a battery, charger and inverter.

6400W of solar is quite a lot of power. You can build a very nice system with quality components for $10k to $30k.

If I use my old mini home electric bill for say the month of February, which used 922kwh for the month?
I was hoping to build a system for under $ 6 000 but it doesn't look like that's doable!

 

[MisterSandals]

February, which used 922kwh for the month?

This is helpful!

922kWh / 30 days = 30kWh per day (quite a bit!) = 30,000Wh

Lets say in Canada you get 2 quality hours of solar each day:

6440W solar x 2h = 12,880Wh harvested each day (about 1/3 of your daily use)

 

[Clinton Earl]

This is helpful!

922kWh / 30 days = 30kWh per day (quite a bit!) = 30,000Wh

Lets say in Canada you get 2 quality hours of solar each day:

6440W solar x 2h = 12,880Wh harvested each day (about 1/3 of your daily use)

I think I was using electric heating quite a lot, trying to save on oil, but my power bill was suddenly more than double!

 

[MisterSandals]

I think I was using electric heating quite a lot, trying to save on oil, but my power bill was suddenly more than double!

Money spent on efficiency, whether it is insulation or other means to reduce usage is more cost effective than buying solar equipment.

 

[Clinton Earl]

Money spent on efficiency, whether it is insulation or other means to reduce usage is more cost effective than buying solar equipment.

I understand that and I'm building a shed connected to my camper, so that I have a cloud in space "outside " of the camper. I also plan to put boards up around the rest of the camper to help keep out the cold but I still need to generate electricity to run the refrigerator, lights, appliances, the campers propane heater, an extra little freezer, etc! I will also have a wood stove in the shed to help with heating

My mini home was around 900 square feet, the camper is 26 × 8', and the attached shed 24 ×16', so at a rough guess it’s less than half the size of my old mini home. So assuming I would need 500 to 600kwh for the month to run everything, where does that put me?
I am trying to put my system together in the simplest possible way, and please correct me if I'm wrong, but it seems that a combined scc/inverter would be the way to go?
I am very thankful for people like you who are smarter than me and willing to help, thank you!

 

[MisterSandals]

for a 24v system at a reasonable price!

Is there a reason you want a 24V battery system?

So assuming I would need 500 to 600kwh for the month to run everything, where does that put me?

550kWh / 30 days = 18.3kWh per day

Lets say in Canada you get 2 quality hours of solar each day:

6440W solar x 2h = 12,880Wh harvested each day (about 1/3 of your daily use)

This is about 2/3 your projected use.