Hi all,

 

I'm currently budgeting to upgrade my solar system for my off grid setup at home. My winter PV production has not been as great as my summer production, which I'm not surprised by.

 

I do, however, want to increase the size of my solar array. What I want to know is, is there a general consensus on whether or not East facing "morning" panels or west facing "evening" panels are worth it? Or would it just make more sense to add another string of north facing panels?

 

I'm currently running a Growatt SPF5000ES, with a Felicity solar 12.5kwh lithium battery, and 1 string of 8 Canadian Solar 600W panels in series. Noticing my morning and evening production has taken a knock this winter and not sure if I should prioritise another string of 8 north facing panels, or if I should look at 4 panels facing east and 4 panels facing west. Very keen to hear what the community feels is best and most efficient/practical. Thanks in advance!

1 hour ago, Islander said:

Hi all,

 

I'm currently budgeting to upgrade my solar system for my off grid setup at home. My winter PV production has not been as great as my summer production, which I'm not surprised by.

 

I do, however, want to increase the size of my solar array. What I want to know is, is there a general consensus on whether or not East facing "morning" panels or west facing "evening" panels are worth it? Or would it just make more sense to add another string of north facing panels?

 

I'm currently running a Growatt SPF5000ES, with a Felicity solar 12.5kwh lithium battery, and 1 string of 8 Canadian Solar 600W panels in series. Noticing my morning and evening production has taken a knock this winter and not sure if I should prioritise another string of 8 north facing panels, or if I should look at 4 panels facing east and 4 panels facing west. Very keen to hear what the community feels is best and most efficient/practical. Thanks in advance!

If you got space North facing is the most effiecient. What is your roof direction facing east and west( true direction use a compass) If direction east is môre north/east you can consider same with west. East or West  you loose 15% efficiency compared to North facing.

West roof faces west fairly straight on. East roof is Northeast facing. North roof is probably 15 degrees west of magnetic north. Plenty of space on all the roofs, and from this information it's looking like north is the best bet right now. 

Thanks for the information here, really interesting to know about the efficiency losses depending on the direction of the panels.

Edited July 31, 20232 yr by Islander

31 minutes ago, Islander said:

West roof faces west fairly straight on. East roof is Northeast facing. North roof is probably 15 degrees west of magnetic north. Plenty of space on all the roofs, and from this information it's looking like north is the best bet right now. 

Thanks for the information here, really interesting to know about the efficiency losses depending on the direction of the panels.

Just confirm whaf the maximum PV is that may be connected to your inverter. Gut tells me you can add 4 similar panels but not 8.

@zsde

I would ask myself 2 questions. 

1. What time of the day do I use the most electricity. 

2. How is your local weather? What time of the day are you most likely to have clear skies. 

I personally like to get power going back into the batteries ASAP. In your case I would personally go NE. 

Your Inverter supports a max 6000W PV input based on 22A. More than that will be clipped.
Looking purely at your 8 current panels, you have a theoretical 4800W, so 2 more will be 6000W. Not sure what the VOC of those panels are. Lets assume ~50V.
That would be 400V with 8 panels which is just about the limit of the MPPT.
More panels would mean two balanced parallel strings to not exceed the max MPPT voltage. If your panels are an assumed 14A, then in parallel you would have 28A, i.e. 6A will be clipped. So you won't get the full potential on sunny days but it will give you more yield on overcast days. Maybe you can post the panel datasheet.
 

i Have installed 8 panels north and 4 panels west and it made a big difference on charging the batteries especially with the Growatt inverter. It seems that the growatt charges in the morning and then again in the late afternoon. The reason for my west facing panels is shading on the 8 panel string from 16:30. My goal is to have the battery at 100% when the sun set especially in winter.  

13 hours ago, Islander said:

Hi all,

 

I'm currently budgeting to upgrade my solar system for my off grid setup at home. My winter PV production has not been as great as my summer production, which I'm not surprised by.

 

I do, however, want to increase the size of my solar array. What I want to know is, is there a general consensus on whether or not East facing "morning" panels or west facing "evening" panels are worth it? Or would it just make more sense to add another string of north facing panels?

 

I'm currently running a Growatt SPF5000ES, with a Felicity solar 12.5kwh lithium battery, and 1 string of 8 Canadian Solar 600W panels in series. Noticing my morning and evening production has taken a knock this winter and not sure if I should prioritise another string of 8 north facing panels, or if I should look at 4 panels facing east and 4 panels facing west. Very keen to hear what the community feels is best and most efficient/practical. Thanks in advance!

After the great rey from @zsde it seems you can only use 10 panels and wired as 2 string of 5 in parallel to the MPPT.

As you have lots of space north that's where I would mount them. This provides the best yield. Refer to the reply from @TaliaB

Try to move large loads to the peak production period 11h-14h.

Hi all, 

Busy day but I'll try respond to everyone:

Should have mentioned I intend to get another Growatt so I can parallel them to have 10KW for the house. This would also allow me to add more panels, of course. 

 

Mppt range on the Growatt as per manual is 120V- 430V, and the VOC is 450.

I'm using the Canadian Solar 600W panels from solarway suppliers. As per the manual on their website:

operating voltage is 34.9V

VOC is 41.3V

Operating current is 17.2A

Short circuit current is 18.47A

 

The majority of my consumption is daytime, however we struggle at night time on occasion and because of this I intend on installing another 12.5kwh battery from felicity solar. We are running that battery to 50-30% overnight and I'm terrified I'm destroying its lifespan.

We're in Mozambique so it's hot as hell but sunny at least almost everyday, except for these overcast days we've experienced this winter. This also has meant extra reliance on the battery which further exasperates my above point.

Attached panel datasheet. Growatt pdf is too large.

CSI-Datasheet-HiKu7_CS7L-MS_v1-3_EN_580-600-4.pdf

Edited August 1, 20232 yr by Islander
Adding information.

29 minutes ago, Islander said:

Hi all, 

Busy day but I'll try respond to everyone:

Should have mentioned I intend to get another Growatt so I can parallel them to have 10KW for the house. This would also allow me to add more panels, of course. 

 

Mppt range on the Growatt as per manual is 120V- 430V, and the VOC is 450.

I'm using the Canadian Solar 600W panels from solarway suppliers. As per the manual on their website:

operating voltage is 34.9V

VOC is 41.3V

Operating current is 17.2A

Short circuit current is 18.47A

 

The majority of my consumption is daytime, however we struggle at night time on occasion and because of this I intend on installing another 12.5kwh battery from felicity solar. We are running that battery to 50-30% overnight and I'm terrified I'm destroying its lifespan.

We're in Mozambique so it's hot as hell but sunny at least almost everyday, except for these overcast days we've experienced this winter. This also has meant extra reliance on the battery which further exasperates my above point.

Attached panel datasheet. Growatt pdf is too large.

CSI-Datasheet-HiKu7_CS7L-MS_v1-3_EN_580-600-4.pdf 911.43 kB · 0 downloads

Now everything changes. 2 parallel strings would now clip from 34A to 22A. So as said stay with single strings. Now we know you can go 9 in series and use both inverters. May be even 10. It just depends on your lowest temp in winter. 

45 minutes ago, Scorp007 said:

Now everything changes. 2 parallel strings would now clip from 34A to 22A.

Thank you for the data on the panels.
Your plans wrt 2 Inverters also changes the planned set up.
With that VOC you should be fine with even 10 panels in series. Doubt the temps in your part of the world ever drop to 10C or lower.
Your initial thoughts on 8 additional would give you 8 series panels into each Inverter then, i.e. ~4800W X 2 = a very nice 9600W PV feed.

2 hours ago, Islander said:

Hi all, 

Busy day but I'll try respond to everyone:

Should have mentioned I intend to get another Growatt so I can parallel them to have 10KW for the house. This would also allow me to add more panels, of course. 

 

Mppt range on the Growatt as per manual is 120V- 430V, and the VOC is 450.

I'm using the Canadian Solar 600W panels from solarway suppliers. As per the manual on their website:

operating voltage is 34.9V

VOC is 41.3V

Operating current is 17.2A

Short circuit current is 18.47A

 

The majority of my consumption is daytime, however we struggle at night time on occasion and because of this I intend on installing another 12.5kwh battery from felicity solar. We are running that battery to 50-30% overnight and I'm terrified I'm destroying its lifespan.

We're in Mozambique so it's hot as hell but sunny at least almost everyday, except for these overcast days we've experienced this winter. This also has meant extra reliance on the battery which further exasperates my above point.

Attached panel datasheet. Growatt pdf is too large.

CSI-Datasheet-HiKu7_CS7L-MS_v1-3_EN_580-600-4.pdf 911.43 kB · 0 downloads

The plan sounds very good and well thought out. Great choice of offgrid inverter having 2 of them seems to be the best scenario where you have enough capacity for peak loads and 2 mppt's for panels to face different directions. 

7 minutes ago, Buyeye said:

The plan sounds very good and well thought out. Great choice of offgrid inverter having 2 of them seems to be the best scenario where you have enough capacity for peak loads and 2 mppt's for panels to face different directions. 

Thanks a lot! That's very kind. Trying my best, previously I had 0 knowledge of anything electrical. Have had to learn from the ground up since moving last year. We are on an island, so completely off grid. Rural area in Mozambique as well which means installation/wiring is up to me. This forum has been an incredible resource of knowledge and learning for someone like me. 

1 hour ago, zsde said:

Thank you for the data on the panels.
Your plans wrt 2 Inverters also changes the planned set up.
With that VOC you should be fine with even 10 panels in series. Doubt the temps in your part of the world ever drop to 10C or lower.
Your initial thoughts on 8 additional would give you 8 series panels into each Inverter then, i.e. ~4800W X 2 = a very nice 9600W PV feed.

I have attached average temperature data from windy.app for 2012-2022. Lowest temp I have ever experienced in 13 years there is about 14 degrees if I remember correctly. Also, side note, I cannot recommend windy.app highly enough for those interested.

2 hours ago, Scorp007 said:

Now everything changes. 2 parallel strings would now clip from 34A to 22A. So as said stay with single strings. Now we know you can go 9 in series and use both inverters. May be even 10. It just depends on your lowest temp in winter. 

This is seriously making me consider investing in making each string 9 panels. I am nervous about going to 10, don't know if I am just being pedantic though. I have seen people on the forum mention over-panelling on the Growatts, but keeping the voltage in line with spec requirements purposefully, so you get your max production from sunrise to sunset. Of course this would be an investment I would only be able to achieve after a while, but I am considering aiming for it, but only if it makes more sense than adding east and west facing strings respectively. This is what I am uncertain of now.

I can afford with my current budget to add one panel to my string of 8, so then my first string will be 9 x 600w panels in series. I can also currently afford to add a second string of 9 panels in series meaning I would have 2 strings of 9 panels, each string in series. Financially I could push each string to 10, but I would only do that if it makes sense to and it's safe to do so, which I would love guidance on.

2 minutes ago, Islander said:

each string 9 panels

Sounds like a safe option.
Have been running my Growatt with two parallel strings for 2 years now. My panels are around 13A, so feeding 26Amps which is clipped at 22A. No issue. My Panel voltages with 6 in series though are only around 300V in idle and drop to around 230V when under full load.
So a second Inverter or a dual MPPT Inverter like the Luxpower would actually provide for better panel power utilisation for my setup.
In your scenario you would be wasting a lot of potential energy if you were to parallel those panels into one Growatt and you also need to consider the 6000W limit.

57 minutes ago, zsde said:

Sounds like a safe option.
Have been running my Growatt with two parallel strings for 2 years now. My panels are around 13A, so feeding 26Amps which is clipped at 22A. No issue. My Panel voltages with 6 in series though are only around 300V in idle and drop to around 230V when under full load.
So a second Inverter or a dual MPPT Inverter like the Luxpower would actually provide for better panel power utilisation for my setup.
In your scenario you would be wasting a lot of potential energy if you were to parallel those panels into one Growatt and you also need to consider the 6000W limit.

It sounds like he is aiming to have 2 inverter with each having a string 9 panels in series. Basically a 10kw inverter with 2 mppt inputs.

At this https://www.solarwaysuppliers.co.za/product/growatt-5kw-inverter-48v-spf500es/ price R24k. You get a proven offgrid inverter with 10kw capacity and 2 mppt's. I would be interested to know if the ac port could be used for a wind turbine In the offgrid setting. 

In the urban setting where utility is available even if unreliable then the luxpower ecohybrid is a better machine only because it can blend all 3 sources. If you have 2 sources to blend then you are not missing out on anything. I have 2 luxpower sna inverters and I'm only using one mppt on each inverter.

 

Edited August 1, 20232 yr by Buyeye

15 minutes ago, Buyeye said:

I have 2 luxpower sna inverters and I'm only using one mppt on each inverter.

Identical to what my neighbour has, and yes, once one has two Inverters the dual MPPT becomes a nice to have.
Security and More just advised that they also received some new stock on the Growatt and it's a at a fairly decent price.  https://www.securityandmore.co.za/products/growatt-spf-5000-es-5kva-5kw-48v-hybrid-inverter-with-wifi

8 minutes ago, zsde said:

Identical to what my neighbour has, and yes, once one has two Inverters the dual MPPT becomes a nice to have.
Security and More just advised that they also received some new stock on the Growatt and it's a at a fairly decent price.  https://www.securityandmore.co.za/products/growatt-spf-5000-es-5kva-5kw-48v-hybrid-inverter-with-wifi

I've been running two growatt's 5000 es in parallel for two years, with 6 X 440 W panels serial strings on each, very happy with the performance. First you get 10 Kw of power and secondly it offers some sort of redundancy if one fails. The offer above is a bargain, cheaper than two years ago. 

14 minutes ago, Antonio de Sa said:

The offer above is a bargain, cheaper than two years ago. 

I am so tempted to get one, but that would be for redundancy only as these new ones can't parallel with the original ones unless the old one is refreshed with new hardware for comms. And I have no idea what those costs will entail.

I don't know if it's even possible but I'm imagining SUB mode where the U is replaced with a wind turbine. 

4 hours ago, Islander said:

Thanks a lot! That's very kind. Trying my best, previously I had 0 knowledge of anything electrical. Have had to learn from the ground up since moving last year. We are on an island, so completely off grid. Rural area in Mozambique as well which means installation/wiring is up to me. This forum has been an incredible resource of knowledge and learning for someone like me. 

I have attached average temperature data from windy.app for 2012-2022. Lowest temp I have ever experienced in 13 years there is about 14 degrees if I remember correctly. Also, side note, I cannot recommend windy.app highly enough for those interested.

This is seriously making me consider investing in making each string 9 panels. I am nervous about going to 10, don't know if I am just being pedantic though. I have seen people on the forum mention over-panelling on the Growatts, but keeping the voltage in line with spec requirements purposefully, so you get your max production from sunrise to sunset. Of course this would be an investment I would only be able to achieve after a while, but I am considering aiming for it, but only if it makes more sense than adding east and west facing strings respectively. This is what I am uncertain of now.

I can afford with my current budget to add one panel to my string of 8, so then my first string will be 9 x 600w panels in series. I can also currently afford to add a second string of 9 panels in series meaning I would have 2 strings of 9 panels, each string in series. Financially I could push each string to 10, but I would only do that if it makes sense to and it's safe to do so, which I would love guidance on.

Nice, cabo delgado or more South? What's the name of the island might pop in when I'm that side of the woods again lol.  Been in and out over the years. 

17 hours ago, Buyeye said:

At this https://www.solarwaysuppliers.co.za/product/growatt-5kw-inverter-48v-spf500es/ price R24k. You get a proven offgrid inverter with 10kw capacity and 2 mppt's. I would be interested to know if the ac port could be used for a wind turbine In the offgrid setting. 

In the urban setting where utility is available even if unreliable then the luxpower ecohybrid is a better machine only because it can blend all 3 sources. If you have 2 sources to blend then you are not missing out on anything. I have 2 luxpower sna inverters and I'm only using one mppt on each inverter.

 

I have been really impressed with solarways prices for everything I have bought from them, must say. I haven't looked into if the AC port could be used for a wind turbine, I know the voltages it accepts are in a range and not just straight 220-230 but I am not looking into a wind turbine right now. Did a bit of research into it and it looked like it would be quite expensive, and I haven't finished with my solar setup. So I figured I would just get my solar system to where I want it then further investigate adding a wind turbine. So right now its only the 2 sources, solar, and my backup generator.

 

17 hours ago, Buyeye said:

It sounds like he is aiming to have 2 inverter with each having a string 9 panels in series. Basically a 10kw inverter with 2 mppt inputs.

Correct. This is my current plan, feel it would make the most sense for me right now.

 

17 hours ago, Antonio de Sa said:

I've been running two growatt's 5000 es in parallel for two years, with 6 X 440 W panels serial strings on each, very happy with the performance. First you get 10 Kw of power and secondly it offers some sort of redundancy if one fails. The offer above is a bargain, cheaper than two years ago. 

This is also my thinking. If one were to pack up for some or other reason, I still have a 5kw inverter to fall back on. That, and they are very competitively priced.

 

16 hours ago, zsde said:

I am so tempted to get one, but that would be for redundancy only as these new ones can't parallel with the original ones unless the old one is refreshed with new hardware for comms. And I have no idea what those costs will entail.

This is concerning. I thought it was as simple as making sure firmware models matched. Any idea how I could find out which model I already have vs which model I would purchase? 

14 hours ago, AndrewJdc said:

Nice, cabo delgado or more South? What's the name of the island might pop in when I'm that side of the woods again lol.  Been in and out over the years. 

Actually in Tete province, inland, we are on lake Cahora Bassa. Opening a tourism business soon.

32 minutes ago, Islander said:

I have been really impressed with solarways prices for everything I have bought from them, must say. I haven't looked into if the AC port could be used for a wind turbine, I know the voltages it accepts are in a range and not just straight 220-230 but I am not looking into a wind turbine right now. Did a bit of research into it and it looked like it would be quite expensive, and I haven't finished with my solar setup. So I figured I would just get my solar system to where I want it then further investigate adding a wind turbine. So right now its only the 2 sources, solar, and my backup generator.

 

Correct. This is my current plan, feel it would make the most sense for me right now.

 

This is also my thinking. If one were to pack up for some or other reason, I still have a 5kw inverter to fall back on. That, and they are very competitively priced.

 

This is concerning. I thought it was as simple as making sure firmware models matched. Any idea how I could find out which model I already have vs which model I would purchase? 

Actually in Tete province, inland, we are on lake Cahora Bassa. Opening a tourism business soon.

By the way, a while back you asked about your earthing system, did you come right? lots of tiger fish in that lake, in the 70's I was in the army protecting the construction of the dam. 

45 minutes ago, Islander said:

This is concerning. I thought it was as simple as making sure firmware models matched. Any idea how I could find out which model I already have vs which model I would purchase? 

There are three versions of this Inverter up to now. The original where the Firmwares are all in  04X.  The second batch the Firmware starts with 06X. and now the latest have the firmwares 11X
If you check your Firmware, you will know which batch you have. Firmware cannot be cross flashed between the versions without hardware changes.

https://watts247.com/product/growatt-can-bus-and-rs485-bms-board-upgrade-older-models/

I found this international site, there might be a shop locally I couldn't find any with a quick search.