How much solar power generated today?

[Goldfinch1]

Hello

Our 4kW solar system generated 4.4kWh today (Sunday 13/03/23) compared with our neighbour’s 6.4kW system which generated 19kWh. Clearly, even taking into account the systems’ size difference, our neighbour’s system appears to have massively outperformed ours. Both systems face, more or less south and have no shading. The pitch of our roof is 40-45 degrees and our neighbour’s is about 35. The weather, here in Bristol, has been overcast for the very large majority of the day and turned to rain by mid-afternoon. Please could any members let me know what their systems produced today, the size of their system and brief idea of what the weather has been like. There is clearly something significant here that I don’t understand and any help would be gratefully appreciated. Many thanks.

 

[TannedITGeek]

Well, I am around 28 miles due south of you and my 6.3kW DC array attached to a 5kW inverter produced 8.8kWh of AC power today. Weather on the whole has been dreadful, although there were some brief periods of bright sunshine in between clouds late morning/lunchtime - this caused the power output of the array to jump to around the 3kW mark (which helped charge the batteries!). I have only just commissioned my system, so are currently addicted to the stats generated and have a screen open on my iPad or phone the whole time, checking the results and tweaking settings on the Victron inverter.

My array of 18 panels is on a barn roof facing SW and since I have felled a couple of trees in front, suffers very little shading.

You say your array is 4kW? Without knowing your system, I am going to hazard a guess that this is hooked up to a 3.6kW AC (G98) inverter? I am also going to assume your neighbour's 6.4kW array is hooked up to a 6kW AC inverter. So there (your neighbour's system), is capable of producing nearly twice the amount of AC power as yours. I agree, the disparity in output production seems on the large side, but without knowing further details on both of your systems - and how the stats are collected, it is difficult to say if there is an issue with your installation.

Feel free to fire over more details and/or drop me a PM if I can be of further help

 

[Goldfinch1]

Well, I am around 28 miles due south of you and my 6.3kW DC array attached to a 5kW inverter produced 8.8kWh of AC power today. Weather on the whole has been dreadful, although there were some brief periods of bright sunshine in between clouds late morning/lunchtime - this caused the power output of the array to jump to around the 3kW mark (which helped charge the batteries!). I have only just commissioned my system, so are currently addicted to the stats generated and have a screen open on my iPad or phone the whole time, checking the results and tweaking settings on the Victron inverter.

My array of 18 panels is on a barn roof facing SW and since I have felled a couple of trees in front, suffers very little shading.

You say your array is 4kW? Without knowing your system, I am going to hazard a guess that this is hooked up to a 3.6kW AC (G98) inverter? I am also going to assume your neighbour's 6.4kW array is hooked up to a 6kW AC inverter. So there (your neighbour's system), is capable of producing nearly twice the amount of AC power as yours. I agree, the disparity in output production seems on the large side, but without knowing further details on both of your systems - and how the stats are collected, it is difficult to say if there is an issue with your installation.

Feel free to fire over more details and/or drop me a PM if I can be of further help

Well, I am around 28 miles due south of you and my 6.3kW DC array attached to a 5kW inverter produced 8.8kWh of AC power today. Weather on the whole has been dreadful, although there were some brief periods of bright sunshine in between clouds late morning/lunchtime - this caused the power output of the array to jump to around the 3kW mark (which helped charge the batteries!). I have only just commissioned my system, so are currently addicted to the stats generated and have a screen open on my iPad or phone the whole time, checking the results and tweaking settings on the Victron inverter.

My array of 18 panels is on a barn roof facing SW and since I have felled a couple of trees in front, suffers very little shading.

You say your array is 4kW? Without knowing your system, I am going to hazard a guess that this is hooked up to a 3.6kW AC (G98) inverter? I am also going to assume your neighbour's 6.4kW array is hooked up to a 6kW AC inverter. So there (your neighbour's system), is capable of producing nearly twice the amount of AC power as yours. I agree, the disparity in output production seems on the large side, but without knowing further details on both of your systems - and how the stats are collected, it is difficult to say if there is an issue with your installation.

Feel free to fire over more details and/or drop me a PM if I can be of further help

Thank you for your reply TannedITGeek. You are right, we have a Solis S6-GR1P 3.6kW dual input inverter with MPPT. Our ten 390 Watt panel are connected in two strings, and yes, I have checked that both strings are working. I have a clamp meter and easy access to cabling in the loft. Our friend’s system has sixteen 390 (?400) Watt panels, also arranged as two strings, connected to two Growatt inverters. Both ourselves and friends take our data from the respective apps we use to monitor our systems. In our case we use SolisCloud, but I don’t know what our friends use. We are also relatively new to solar energy (3 months) and, like you, monitor performance very frequently. Taken at face value, our relative output yesterday aligns more closely with yours than our neighbour’s. I have also tried to assess our achieved monthly output too date against that predicted by our supplier and have an Excel graph which I plot predicted output against achieved (I too, can be a bit of a geek at times). When I constructed the graph I took into account, as best as I could, output variation due to the shorter winter days (there’s resources on the internet to help with this). So far, we appear to be meeting predicted performance, but given the awful weather we have experienced in March, this might not be the case by the end of the month. Don’t know whether this is any help, but thanks again for your thoughts.

 

[bigspark17]

Well, I am around 28 miles due south of you and my 6.3kW DC array attached to a 5kW inverter produced 8.8kWh of AC power today. Weather on the whole has been dreadful, although there were some brief periods of bright sunshine in between clouds late morning/lunchtime - this caused the power output of the array to jump to around the 3kW mark (which helped charge the batteries!). I have only just commissioned my system, so are currently addicted to the stats generated and have a screen open on my iPad or phone the whole time, checking the results and tweaking settings on the Victron inverter.

My array of 18 panels is on a barn roof facing SW and since I have felled a couple of trees in front, suffers very little shading.

You say your array is 4kW? Without knowing your system, I am going to hazard a guess that this is hooked up to a 3.6kW AC (G98) inverter? I am also going to assume your neighbour's 6.4kW array is hooked up to a 6kW AC inverter. So there (your neighbour's system), is capable of producing nearly twice the amount of AC power as yours. I agree, the disparity in output production seems on the large side, but without knowing further details on both of your systems - and how the stats are collected, it is difficult to say if there is an issue with your installation.

Feel free to fire over more details and/or drop me a PM if I can be of further help

What settings are you tweaking?