LG Chem battery efficiency

[edk_fan]

Okay, that explains. My installer is currently very adversarial, so I don't think I will ask now, but certainly will do so in the future.

By the way: I can still extract CSV values, and do many of the same analyses. The full access options seem to allow you to do this in a more user-friendly manner though.

[Srrndhound]

I don't have that data analysis tab in my SolarEdge monitoring. Any clue what I need to do to get this? Is this something my installer can activate? Or I don't have because my battery is not from SolarEdge themselves?

I did not have all the tabs initially, either. There are 3 tiers of "owner role":
 The Dashboard role allows the system owner to access to the Dashboard tab only.
 The Dashboard & Layout role allows the system owner to access the Dashboard and Layout tabs.
 The Full access role allows the system owner to access the Dashboard, Layout, Chart, Reports and Alerts tabs.

You of course want Full Access, and a phone call to my dealer got it done quickly. Full Access also allows you to change the battery reserve percentage.

[Bob Moffit]

82.5% is on the lower end, but I believe this may also include losses in the inverter and it definitely includes standbye consumption. So, you cannot expect to gain the round-trip efficiency listed on the datasheet. Still seems pretty low though...I would inquire with SE whether this is normal (and let me know the outcome )

I don't have that data analysis tab in my SolarEdge monitoring. Any clue what I need to do to get this? Is this something my installer can activate? Or I don't have because my battery is not from SolarEdge themselves?

Hi EDK_Fan, I have gone back to the installer over this weekend with some questions. If I learn something interesting, I'll post it. Originally, we were scheduled to get an LG battery but there were supply issues and delays, and in the meantime, SE ended up introducing their battery, so we end up with the Solar Edge. The reason I mention this is because before we decided to go with SE, I was told that the LG would be monitored through the SE app, so I think that your battery would also be able to be monitored.

I'm surprised that you wouldn't have the analysis tab on your Solar Edge application (computer - not phone app). This seems to be the only useful tab (in my opinion) outside of the dashboard. You probably want to talk to your installer and see what you need to do to get access to this tab.

[oregon_phil]

The power in W multiplied by the duration over which that power is exerted gives you the energy in Wh. Because the SolarEdge values are 15-minute values, you have to multiple the power by 15/60 (=dividing by 4). I divide by 4000 so I obtain kWh instead of Wh values. Is that clear now?

Disclaimer: I'm not a battery person nor do I own a SolarEdge system. I have an SMA string inverter system; no batteries.

Since I don't have a battery, I'll just use solar power for conversations sake. My SMA inverter can export data collected at 5 minute intervals, will display all variables on the web viewer every 2 seconds and internally calculates variables every xx (?) microseconds. Fortunately, my data log file contains a total energy meter and average power meter at 5 minute intervals.

I downloaded 3 hours worth of data the other morning.

Even at 5 minute intervals, my calculated power using (Average Watts * (5/60)) hr is between 48 to 104% when compared to the actual total energy meter; worse at start up and better late morning.

I'm not sure how SolarEdge calculates average power at 15 minute intervals, but at that data rate, I would just view that number as a number. Unless energy in and out happen as step functions in 15 minute intervals, calculating energy from power seems like it be an estimate in the ballpark. Maybe SolarEdge would share their test methodologies to calculate Peak Roundtrip Efficiency.

[edk_fan]

82.5% is on the lower end, but I believe this may also include losses in the inverter and it definitely includes standbye consumption. So, you cannot expect to gain the round-trip efficiency listed on the datasheet. Still seems pretty low though...I would inquire with SE whether this is normal (and let me know the outcome )

I don't have that data analysis tab in my SolarEdge monitoring. Any clue what I need to do to get this? Is this something my installer can activate? Or I don't have because my battery is not from SolarEdge themselves?

[Srrndhound]

I think this should help you get the data. After you generate the chart on the screen, you export it to CSV file (excel) using the icon circled in the upper right corner. When you choose the CSV file you can choose from a couple of different data frequency options.

That worked. Wow, very powerful tool, that analysis tab. Thanks.

[Bob Moffit]

Battery.png

Could you post a screenshot showing where you click to access "Charged Power" data? I'd like to repeat the process here. Thanks.

I think this should help you get the data. After you generate the chart on the screen, you export it to CSV file (excel) using the icon circled in the upper right corner. When you choose the CSV file you can choose from a couple of different data frequency options.

[Srrndhound]

I have a Solar Edge system, including 10KWh SE battery. I just pulled the data using the following: Charts / Battery (selected "Charged Power" and "Discharge Power").

Could you post a screenshot showing where you click to access "Charged Power" data? I'd like to repeat the process here. Thanks.

[Bob Moffit]

I have a Solar Edge system, including 10KWh SE battery. I just pulled the data using the following: Charts / Battery (selected "Charged Power" and "Discharge Power"). It pulled up a 24 hour curve for both, so I selected a one month view (hourly data) and then exported to CSV file. In the CSV file I just summed the two columns and it showed an 85.2% efficiency. I'm not positive if I'm looking at this right, but if I am (or am not) I'd appreciate anyone letting me know.

The SE Battery cutsheet states "Peak round-trip efficiency >94.5%"
It seems like that is the value that I should be getting??

[edk_fan]

Very interesting, thanks for checking! An 80% efficiency is perhaps on the lower end, but I could understand that. You have losses in the inverter and the battery, and you have some standby consumption of the battery itself. These factors combined could potentially explain a 20% loss I think.

[Srrndhound]

The power in W multiplied by the duration over which that power is exerted gives you the energy in Wh. Because the SolarEdge values are 15-minute values, you have to multiple the power by 15/60 (=dividing by 4). I divide by 4000 so I obtain kWh instead of Wh values. Is that clear now?

Yes, thanks. I think I see now.

Your info made me curious to see what’s happening here.

In my data, I am looking at one day where the starting battery charge level just happened to be exactly the same 24 hours later. During that period the battery discharged to the prescribed reserve (30%), then recharged to 99.9%. The battery took 14.6 kWh to charge, and delivered 11.6 kWh of output. As in your case, there’s an efficiency gap – in my case 20% goes missing somewhere.

On paper the batteries are spec’d as 19.4 kWh, 70% of which would be 13.6 kWh. That falls somewhere between the charge and discharge data.

These are SolarEdge Energy Bank batteries.

[edk_fan]

The power in W multiplied by the duration over which that power is exerted gives you the energy in Wh. Because the SolarEdge values are 15-minute values, you have to multiple the power by 15/60 (=dividing by 4). I divide by 4000 so I obtain kWh instead of Wh values. Is that clear now?

[Srrndhound]

Yes, this is from the SolarEdge monitoring app. You can download the CSV files in the webversion, and that gets you a range of 15-minute values. Based on Storage Power.Power(W), you can then calculate the total energy that was charged or discharged to your battery.

Yes, I had looked at the downloaded file, but I'm still not clear how you find or calculate the energy going into the battery. Sorry, I'm a recent owner.

[edk_fan]

Yes, this is from the SolarEdge monitoring app. You can download the CSV files in the webversion, and that gets you a range of 15-minute values. Based on Storage Power.Power(W), you can then calculate the total energy that was charged or discharged to your battery.

[Srrndhound]

When the system charged 8 kWh of energy into my battery in 4h45min, then 77.7% or 7.6 kWh of energy was added to my battery.

Is this data from the SolarEdge monitor? I cannot find daily battery charge energy, all I have is % of charge.