So I had the plant overview open all day and couldn't stop watching it

It was a fairly busy day in the house, the helpers were all here doing their thing, dishwasher running, washing machine going, coffee being made in the mornings and afternoons, the TV's and sound systems going, and my gaming PC running all day. It was an overcast day in Joburg with spots of rain, and I was quite impressed with the PV, as it held up quite nicely throughout the day and was able to cope with most of the load. See below:

 

I still have to install 3 east facing panels, so my generation capacity will increase in the mornings. Currently I'm just using the default system mode settings

I know it might be hasty but I'm already looking into what the optimum configuration will be for my setup to use as little power from the grid as possible. From the diagram, it looks like I start generating a little bit at 6am and it starts to drop at 6pm. I have an east / west solar panel layout, so my peak generation is in the morning and the afternoon. With that said, these are my time of use settings I'm thinking of using (no grid charge selected):

1-6 : 20%
6-10 : 80%
10-14 : 40%
14-18 : 80%
18-20 : 60%
20-1 : 40%

This way, I can discharge when it's night time and charge during the day, and then discharge a little in the middle of the day as well. I have a few questions:

1. What are your thoughts on the above configuration? Am I being too hasty, should I wait a bit to see my usage patterns over a short period or should I do it by trial and error?
2. During loadshedding and at night with no solar power, if the SOC drops to below the threshold configured in the Timer, what happens? I'm guessing it will just keep discharging the battery and then charge it back up to the configured SOC value for that timeslot when solar power is back. And if it does drop below the battery shutoff, the inverter will shutoff the AC output and restart the AC output when the battery reaches the restart threshold.
   1. My current battery settings are, 20% shutdown, 35% low batt, 50% restart. What are your thoughts on this?
3. If there is excess PV, will the inverter keep charging the batteries above the SOC configured for that timer, e.g. if the SOC is set to 80%, could the battery be charged up to 100% or will the inverter only charge the battery to the SOC that's been configured and keep it there?

 

7 hours ago, kamos said:

So I had the plant overview open all day and couldn't stop watching it

It was a fairly busy day in the house, the helpers were all here doing their thing, dishwasher running, washing machine going, coffee being made in the mornings and afternoons, the TV's and sound systems going, and my gaming PC running all day. It was an overcast day in Joburg with spots of rain, and I was quite impressed with the PV, as it held up quite nicely throughout the day and was able to cope with most of the load. See below:

 

I still have to install 3 east facing panels, so my generation capacity will increase in the mornings. Currently I'm just using the default system mode settings

I know it might be hasty but I'm already looking into what the optimum configuration will be for my setup to use as little power from the grid as possible. From the diagram, it looks like I start generating a little bit at 6am and it starts to drop at 6pm. I have an east / west solar panel layout, so my peak generation is in the morning and the afternoon. With that said, these are my time of use settings I'm thinking of using (no grid charge selected):

1-6 : 20%
6-10 : 80%
10-14 : 40%
14-18 : 80%
18-20 : 60%
20-1 : 40%

This way, I can discharge when it's night time and charge during the day, and then discharge a little in the middle of the day as well. I have a few questions:

1. What are your thoughts on the above configuration? Am I being too hasty, should I wait a bit to see my usage patterns over a short period or should I do it by trial and error?
2. During loadshedding and at night with no solar power, if the SOC drops to below the threshold configured in the Timer, what happens? I'm guessing it will just keep discharging the battery and then charge it back up to the configured SOC value for that timeslot when solar power is back. And if it does drop below the battery shutoff, the inverter will shutoff the AC output and restart the AC output when the battery reaches the restart threshold.
   1. My current battery settings are, 20% shutdown, 35% low batt, 50% restart. What are your thoughts on this?
3. If there is excess PV, will the inverter keep charging the batteries above the SOC configured for that timer, e.g. if the SOC is set to 80%, could the battery be charged up to 100% or will the inverter only charge the battery to the SOC that's been configured and keep it there?

 

What will likely happen is you will continually refine the settings for weeks to come then settle after that.

1 - nothing wrong with starting but as i said you will likely change as you understand how your household uses power. sunny days are a breeze - its the overcast / rainy ones than can be a challenge

2 - Your switch to grid + battery cutoff are the same value - so if you have loadshedding in the 4-6am slot and there isnt much sun around 6 then your system will likely switch off. Perhaps make your battery cut-off 15% to give you that buffer in those situations. you might also want to change your restart to something like 25% and loww batt 20%

3 -the battery will be charged to 100%, remember those % are the minimum before it switches to the grid. If there is excess PV it will go all the way up. If there is les then it will go down to say 80% then switch to grid until the next timeslot

I've noticed a few things:

a. "Use timer" isn't ticked so your schedule isn't active right now.

b. There's a lot of grid usage during the day as if the inverter isn't using PV to the full potential (but it might be that the PV was too low due to rain and clouds) but why isn't it supplementing load by using the battery then? Also, it was using a lot of grid to charge the battery at 5:00 and 22:30?

PS: I'm still a newbie and pre-solar so my comments might be rubbish.

12 minutes ago, p_i said:

I've noticed a few things:

a. "Use timer" isn't ticked so your schedule isn't active right now.

b. There's a lot of grid usage during the day as if the inverter isn't using PV to the full potential (but it might be that the PV was too low due to rain and clouds) but why isn't it supplementing load by using the battery then? Also, it was using a lot of grid to charge the battery at 5:00 and 22:30?

PS: I'm still a newbie and pre-solar so my comments might be rubbish.

Definitely not rubbish - that's how we all learn and you are spot on - it looks like the timer settings are not in use

5 hours ago, mzezman said:

What will likely happen is you will continually refine the settings for weeks to come then settle after that.

1 - nothing wrong with starting but as i said you will likely change as you understand how your household uses power. sunny days are a breeze - its the overcast / rainy ones than can be a challenge

2 - Your switch to grid + battery cutoff are the same value - so if you have loadshedding in the 4-6am slot and there isnt much sun around 6 then your system will likely switch off. Perhaps make your battery cut-off 15% to give you that buffer in those situations. you might also want to change your restart to something like 25% and loww batt 20%

3 -the battery will be charged to 100%, remember those % are the minimum before it switches to the grid. If there is excess PV it will go all the way up. If there is les then it will go down to say 80% then switch to grid until the next timeslot

Thanks for the info. My understanding of the cutoff is that it will shutdown if it goes below that value. So setting it to 20% won't trigger the shutdown, as long as I have grid charge ticked, which I think I might do just in case. However, my installer says with my load it's unlikely that I will run the battery down to 20% at night, because my base load at night is very low (170W).

The installer suggested that I shut the battery off tonight and see how it performs, he is quite confident that I won't need the grid and that my battery should easily last through the night.

4 hours ago, p_i said:

I've noticed a few things:

a. "Use timer" isn't ticked so your schedule isn't active right now.

b. There's a lot of grid usage during the day as if the inverter isn't using PV to the full potential (but it might be that the PV was too low due to rain and clouds) but why isn't it supplementing load by using the battery then? Also, it was using a lot of grid to charge the battery at 5:00 and 22:30?

PS: I'm still a newbie and pre-solar so my comments might be rubbish.

 

13 hours ago, kamos said:

Currently I'm just using the default system mode settings

 

a. Yes, I haven't setup the timer yet, I'm waiting for the install to be completed today. My installer and I are still discussing options.

b. Two reasons for this. Firstly, I was wrong when I said that there were only 3 panels outstanding, it turns out that only 7 panels on the west side had been enabled yesterday. The other 7 will be connected today on the east side. Also, those spikes are due to boiling the kettle and using the dishwasher / washing machines. No timers are enabled, so my understanding is that the inverter will take a little from the grid initially then the PV will come in with a little bit of a delay to cover the power required. The battery will be kept at 100% by default. I think once the timers are enabled, it should pull from the battery first and then come in with PV.

A separate question, I thought that the panels would generate maximum power based on weather conditions, i.e. if the power generated is 2kw, that the inverter would have that shown as the generation capacity available. But in reality, the PV functions more like an on-demand service, the inverter will request a certain amount of power draw, and the PV will provide only what has been requested up to what it's maximum generation ability is at that time. If the requested power is higher than what the PV can provide, the inverter will take the rest from the other power sources, grid / battery based on the system modes selected.

Have a look at my current power flow:

 

We've turned off the mains. I thought that the PV would provide it's maximum available generation capability, but it's only providing enough to cover the load. And limit-to-load is not ticked. When I switch on the kettle, the PV jumps to 2536W to cover the load, then goes back down once the kettle is done boiling.

Why is this?

That's just how it works. PV can't provide power if there's nowhere for it to go, ie. nothing available to use it. As you noticed with the kettle, PV will provide the necessary power as soon as you need it.

1 minute ago, kamos said:

Why is this?

Your battery is at 100%, so the system does not have an 'outlet' for the additional PV capacity. It hence 'restricts' the PV production to what is required by the load.

You will see that you PV generates as much as it can when your battery is not fully charged.

Also not that the PV ramp-up to a sudden change in load is not instantaneous. You will see a slight lag in PV production when you suddenly increase your load (e.g. switch on the kettle). In the meantime, your inverter will draw the balance from the other available sources (usually battery)

17 minutes ago, p_i said:

That's just how it works. PV can't provide power if there's nowhere for it to go, ie. nothing available to use it. As you noticed with the kettle, PV will provide the necessary power as soon as you need it.

 

16 minutes ago, wolfandy said:

Your battery is at 100%, so the system does not have an 'outlet' for the additional PV capacity. It hence 'restricts' the PV production to what is required by the load.

You will see that you PV generates as much as it can when your battery is not fully charged.

Also not that the PV ramp-up to a sudden change in load is not instantaneous. You will see a slight lag in PV production when you suddenly increase your load (e.g. switch on the kettle). In the meantime, your inverter will draw the balance from the other available sources (usually battery)

Thanks for this. I appreciate the feedback. It makes sense.

4 hours ago, kamos said:

Thanks for the info. My understanding of the cutoff is that it will shutdown if it goes below that value. So setting it to 20% won't trigger the shutdown, as long as I have grid charge ticked, which I think I might do just in case.

So my understanding was wrong. Luke showed me that you can't set the timer SOC to a value lower than the low battery warning value. Mine is currently set to 30%. I guess that's some sort of safety feature.

Btw, I turned the mains off at 5pm. Battery is performing well so far.

 

44 minutes ago, kamos said:

Btw, I turned the mains off at 5pm. Battery is performing well so far.

And you're still getting a little power from PV too... nice.

1 hour ago, kamos said:

So my understanding was wrong. Luke showed me that you can't set the timer SOC to a value lower than the low battery warning value. Mine is currently set to 30%. I guess that's some sort of safety feature.

Btw, I turned the mains off at 5pm. Battery is performing well so far.

 

Just out of interest, have you done a capacity test on the battery to see how much of the 12.5kwh you get out of it.

By example, let it run down from 100% to 20% and note how much power it provided, then charge back to 100% an note how much was put back into it. Work back to see how that 80% used translates to compared to the 12.5kWh capacity as a very high level approximation 

Edited November 23, 20223 yr by I84RiS

So last night they completed the installation of my system, we did a few final configurations and the installer suggested that we run down the battery over night to see how it performs and how long I can go on battery with normal usage. So as soon as he left, I switched off the mains. These are the results:
 

 

The battery made it through the night, with no issues. The PV kicked in shortly after sunrise, and started charging the battery. I'm so stoked with this system, it is performing way beyond my expectations! 

And as an added bonus, there was a 6 hour outage in my area today from 9am to 3pm, and I had power all the way through it, no issues, while my neighbours were complaining like crazy. It feels so good being almost independent from Eksom.  It's cloudy in Joburg today, and my PV is handling the load just fine. I'm basically pulling nothing from the grid

It's looking great. Seems the battery dropped to about 38% SOC during the night but was fully charged before 10:00. And each time you used a little bit of battery due to load, the PV kicked in to recharge it back to 100%. That's a beautiful graph to sit and watch.

So far my experience has been amazing and I'm super stoked. Before I bought the equipment, I did so much research and calculations on ROI, not once did I consider the quality of life improvement that solar brings. My area has had multiple outages since Friday, averaging 6-8 hours DAILY. You can't put a number on how good it feels to not have to worry about loadshedding, it's priceless and I have zero regrets.

Quick question, my solar system was installed on 24 November and I've been running the system for 5 days. I've basically been running on PV and Battery, with very little to no import from Eskom. Here's an overview:

 

I do have one question though. There are spikes in during the day where we do pull from the grid initially (even though the battery has 100% SOC), and they the PV / Battery will take over moments later. And then other times it solely relies on PV / Battery to deal with the load, See the examples below:

Is this normal behaviour? Why isn't the inverter always pulling from Battery / PV first?

 

1 hour ago, kamos said:

I do have one question though. There are spikes in during the day where we do pull from the grid initially (even though the battery has 100% SOC), and they the PV / Battery will take over moments later. And then other times it solely relies on PV / Battery to deal with the load, See the examples below:

Is this normal behaviour? Why isn't the inverter always pulling from Battery / PV first?

I believe it's simply a case of PV not able to ramp up quickly enough to provide the required power.

12 minutes ago, p_i said:

I believe it's simply a case of PV not able to ramp up quickly enough to provide the required power.

Ok, thanks for that. So it's normal behaviour then. 

5 hours ago, kamos said:

So far my experience has been amazing and I'm super stoked. Before I bought the equipment, I did so much research and calculations on ROI, not once did I consider the quality of life improvement that solar brings. My area has had multiple outages since Friday, averaging 6-8 hours DAILY. You can't put a number on how good it feels to not have to worry about loadshedding, it's priceless and I have zero regrets.

Quick question, my solar system was installed on 24 November and I've been running the system for 5 days. I've basically been running on PV and Battery, with very little to no import from Eskom. Here's an overview:

 

I do have one question though. There are spikes in during the day where we do pull from the grid initially (even though the battery has 100% SOC), and they the PV / Battery will take over moments later. And then other times it solely relies on PV / Battery to deal with the load, See the examples below:

Is this normal behaviour? Why isn't the inverter always pulling from Battery / PV first?

 

I guess you could eliminate this by totally turning off the main grid input 

Edited November 28, 20223 yr by mzezman

7 hours ago, kamos said:

So far my experience has been amazing and I'm super stoked. Before I bought the equipment, I did so much research and calculations on ROI, not once did I consider the quality of life improvement that solar brings. My area has had multiple outages since Friday, averaging 6-8 hours DAILY. You can't put a number on how good it feels to not have to worry about loadshedding, it's priceless and I have zero regrets.

Quick question, my solar system was installed on 24 November and I've been running the system for 5 days. I've basically been running on PV and Battery, with very little to no import from Eskom. Here's an overview:

 

I do have one question though. There are spikes in during the day where we do pull from the grid initially (even though the battery has 100% SOC), and they the PV / Battery will take over moments later. And then other times it solely relies on PV / Battery to deal with the load, See the examples below:

Is this normal behaviour? Why isn't the inverter always pulling from Battery / PV first?

 

If your settings are correct it should pull from PV first, if PV cannot supply the load fast enough it should use the battery to momenteroly supply the shortfall. Grid should not supply anything.

 

Is your work mode (use timer) enabled? Also, if you want it to work like this it should not be set to maintain a 100% SOC on work mode

Edited November 28, 20223 yr by I84RiS

1 hour ago, I84RiS said:

If your settings are correct it should pull from PV first, if PV cannot supply the load fast enough it should use the battery to momenteroly supply the shortfall. Grid should not supply anything.

 

Is your work mode (use timer) enabled? Also, if you want it to work like this it should not be set to maintain a 100% SOC on work mode

Use Timer is enabled and I have the SOC set to 80% in that time slot.

If you compare the screenshots above with the spikes, you can see that in the one the battery was busy charging, had to stop charging and start discharging, then only then did it kick it with the PV. In the other picture, the battery was idle. So I'm guessing it's because the battery was charging, that's why the inverter decided to get the power from the grid first, as maybe the battery was ready to deliver that kind of power?