Hi, im new here.

 

I have got a small solar system so run the house (excluding geysers and stove)

I have got a synapse 3kva inverter, 2 x 12v 200ah solar gel batteries and 2 x 350w solar panels.

It works perfectly for load shedding, but i want to run the house from it completely, charging only with the solar and not utilities, how do i calculate the max number of solar panels i can add to it. ( series or parallel )

And i have got an extra 350w panel and can get 360w and 390 w panels, will htey work ?

1 hour ago, Jaco Minnie said:

Hi, im new here.

 

I have got a small solar system so run the house (excluding geysers and stove)

I have got a synapse 3kva inverter, 2 x 12v 200ah solar gel batteries and 2 x 350w solar panels.

It works perfectly for load shedding, but i want to run the house from it completely, charging only with the solar and not utilities, how do i calculate the max number of solar panels i can add to it. ( series or parallel )

And i have got an extra 350w panel and can get 360w and 390 w panels, will htey work ?

Hello Jaco, welcome to the Powerforum and congrats on your first post!

Running a whole home is a bit of a lofty goal, and 3kVA is generally a bit smallish for a house (not impossible though), but maybe your needs are small too: What is your daily consumption (kWh)?

Even if you cannot run the whole home, it's good to understand what you potentially can do, planning for optimising your investment can be fun. So for starters, let's determine the maximum energy that your inverter can generate. For that we will need to understand the Synapse 3k inverter's capabilities. What is the MPPT controller's specs? It's usually in the manual (or sometimes on a sticker on the side or bottom of the inverter)        

12 hours ago, Jaco Minnie said:

Hi, im new here.

 

I have got a small solar system so run the house (excluding geysers and stove)

I have got a synapse 3kva inverter, 2 x 12v 200ah solar gel batteries and 2 x 350w solar panels.

It works perfectly for load shedding, but i want to run the house from it completely, charging only with the solar and not utilities, how do i calculate the max number of solar panels i can add to it. ( series or parallel )

And i have got an extra 350w panel and can get 360w and 390 w panels, will htey work ?

Rough estimation, take the 3000W/350w if using 350w pv panels, will give you 8,57 number of panels to use. Round that off and make it 9 panels. How you wire them to your inverter, will require you to check the spec of your MPPT so that you do not blow it up in smoke. If using the 360w panels, follow the same step but divide with 360w to get the number of panels 

Edited September 1, 20214 yr by hoohloc
spelling

7 minutes ago, hoohloc said:

Rough estimation, take the 3000W/350w if using 350w pv panels, will give you 8,57 number of panels to use. Round that off and make it 9 panels. How you wire them to your inverter, will require you to check the spec of your MPPT so that you do not blow it up in smoke. If using the 360w panels, follow the same step but divide with 360w to get the number of panels 

Highly doubt that MPPT can take 3000w max on that inverter. 

Best to get the proper specs posted before he heads off and buy panels he can't use

1 hour ago, JoeyhZA said:

Highly doubt that MPPT can take 3000w max on that inverter. 

Best to get the proper specs posted before he heads off and buy panels he can't use

Even with the spec posted, he might not have the right incline angle on his roof, or Shades, or no North facing roof etc, to be able to use the full potential of the panels. Over sizing helps, especially in winter or cloudy days. So I stand by my rough estimation above and I can guarantee you that he will make use of all the nine panels 😀

4 minutes ago, hoohloc said:

Even with the spec posted, he might not have the right incline angle on his roof, or Shades, or no North facing roof etc, to be able to use the full potential of the panels. Over sizing helps, especially in winter or cloudy days. So I stand by my rough estimation above and I can guarantee you that he will make use of all the nine panels 😀

As with beer... or ammunition... you simply can't ever have enough.

I have a 'spare' two strings on a separate inverter (on a manual breaker) adding an additional 4Kw into my home system just for those inclement days. Consequently I have never needed to supplement with the standby generator.

brilliant, thanks for the replies, sorry im only getting back to you now, hectic week, late nights.

i took screenshot of the specs, if its not enough i will go find the booklet.

please see attached.

i dont know our exact usage per day, but our towns power was off the other day for repairs to overhead lines and

we had inverter power for the whole day.

Thank you. The key figures are:

Max voltage of the string/s: 102V

MPPT range: 30-80V

Max power: 1000W

Any panel configuration, whether serial or parallel or a combo should never exceed 102V, because it will burn. I'm not sure if the MPPT will clip the amps, so let's assume it does not, best not to exceed 12.5 A

For new panels, follow the steps in this guide: https://unboundsolar.com/blog/string-sizing-guide

If you want to re-use your two 350W panels we will need to know what the specs are, usually supplied with them:

1. VoC at STC

2. Vmp at STC

3. NOCT operating conditions

4. Temperature coefficient of VoC

I am guessing that they are around 47.8.V VoC and 9.8A Vmp, and that they are in series, which does not give you room for adding another panel (you are already at 95.6V).    

You can probably only have 4 350W panels (2 strings of 2 panels each connected in parallel). You'd need to upgrade your inverter to add more panels or buy a separate MPPT.

great guys, thank you, i will climb on the roof today and take a photo of the specs.

 

really appreciate all the advice