Inverter Kwh meter

[Wescottpower]

I have a sungold power 12kw running a supplemental breaker box with my primary circuits on it. I have 10 550w panels and the kWh meter on the inverter says I’m only making about 4.5-5.5kwh per day. Panels are at optimal angle for the time of year facing south with unhindered sun exposure from about 8am until 6:30pm. Our household uses about 2800-3000 kWh per month and I wanted to use this as a supplement but I’m not feeling I’m getting the output I should be. Not sure what I’m doing wrong or if that meter is accurate. I have 2s3p going into pv1 input and 2s2p going into pv2 input. It’s a 48v system with 16S 202ah battery bank. Daly 200 amp bms and active balancer. I added more circuits to my sub panel this weekend and the inverter runs on PV mode all day long and keeps up. Readout on inverter states anywhere from 16%-45% throughout the day. I thought adding more circuits would get me more kWh’s but still the same daily meter reading. Any ideas?

 

[42OhmsPA]

Do you have any logs / charts showing your production?

Looking at the specs it seems like your maxing out one of the mppts, something definitely isn't right.
What's the voc of your panels? You might get away with wiring 3s but it's doubtful if you're in a cold climate.

Solar Charger

• Maximum PV Charge Current: 120A (60A+60A)
• Maximum PV Array Power: 7000W (2x3500W)
• MPPT Range (VDC): 60-145Vdc
• Maximum PV Array Open Circuit Voltage: 155V

 

[Wescottpower]

I just started recording the inverter meter readings last Wednesday when I finished getting my inverter/BMS settings optimized. I only have about 5 days recorded with weather conditions noted.
Panel spec:
Maximum Power (Pmax) 550W
Max-power Voltage (Vmp) 41.96V
Max-power Current (Imp) 13.11A
Open-circuit Voltage (Voc) 49.9V
Short-circuit Current (Isc) 14.01A

I had asked in another post what was the best panel wiring arrangement and being in a cold weather climate, it was suggested I stay with the 2s3p wiring of the panels. Speaking with Sungold power support they said it was perfectly fine to have a mismatch between PV1 and PV2 inputs. Using #10 1000v extensions from panels to combiner box, wire gauge for both PV inputs from combiner box is #6awg. Each pair of panels has a dedicated 20amp fuse combining into a single 63amp double pole breaker for each PV input. All circuits by themselves are producing power and breakers are closed. I'm stumped

 

[Wescottpower]

Just received a reply from Sungold;

"The PV power displayed on the LCD, it is not the maximum power that can be generated by the solar panel, but the actual power used of PV output power, which depends on the load demand and the charging demand. It will not show the actual power the solar panels have. It actually shows the amount of energy that it requires at that point in time. If your batteries are full or there's little to no AC output load, even if the PV has several kilowatts of electricity at this time, the screen will only show a small value."

Guess I need to move more load to the subpanel because I should be making approx. 20kWh per day average. I wish this inverter had more configurable settings to maximize the DC to AC switch over. I can only set at 2v increments, 46 is too low (BMS shutdown) and 48 is premature. Newb trial an error I guess.

 

[Berseker]

I have a sungold power 12kw running a supplemental breaker box with my primary circuits on it. I have 10 550w panels and the kWh meter on the inverter says I’m only making about 4.5-5.5kwh per day. Panels are at optimal angle for the time of year facing south with unhindered sun exposure from about 8am until 6:30pm. Our household uses about 2800-3000 kWh per month and I wanted to use this as a supplement but I’m not feeling I’m getting the output I should be. Not sure what I’m doing wrong or if that meter is accurate. I have 2s3p going into pv1 input and 2s2p going into pv2 input. It’s a 48v system with 16S 202ah battery bank. Daly 200 amp bms and active balancer. I added more circuits to my sub panel this weekend and the inverter runs on PV mode all day long and keeps up. Readout on inverter states anywhere from 16%-45% throughout the day. I thought adding more circuits would get me more kWh’s but still the same daily meter reading. Any ideas?

errrm is this a typo. if you are using 3000kwh per month, that averages to 100kwh per day. the combined energy of your battery and panels isn't near that.

if your battery is full, or gets full early...then the panels would not have anywhere to dump their harvested energy, so it will throttle harvest.
you have several options to figure this out.
1. install a tuya wifi kwh usage device, if your inverter load tracking logs isn't accurate. this way you can be sure of your actual daily load consumption. if your consumption is close to your harvest..then you don't have any issue. as your panels are being throttled.

2. another simpler way, is to check the remaining ah/capacity of your battery bank before sunrise, your bms Bluetooth app should do this neatly...that would tell you what you used the day before

 

[Wescottpower]

Yes, you are correct that my system isn't near that. And no that's not a typo, if it was just me living here, I could be off grid completely with a generator boost once in a while!

I'm looking at data loggers right now, what are some inexpensive options? I was looking at the Emporia CT system, any other suggestions?

my inverter goes into AC mode at night once the batteries are discharged and will top off the batteries. I have it set at the lowest (AC) charge rate 16amps but by morning they are 98-100%. Another battery bank is in the future but until then I have to make do with what I have. Thats why I'm asking questions on how to get the max yield out of the system i have because I don't think I am right now. Like you said, the PV's are probably getting throttled back currently. I will be adding more load to the system this weekend.

 

[740GLE]

3000kwhr/month? did your utility used to send you holiday thank you cards each year?

If not, they should have!!!

 

[Berseker]

Yes, you are correct that my system isn't near that. And no that's not a typo, if it was just me living here, I could be off grid completely with a generator boost once in a while!

I'm looking at data loggers right now, what are some inexpensive options? I was looking at the Emporia CT system, any other suggestions?

my inverter goes into AC mode at night once the batteries are discharged and will top off the batteries. I have it set at the lowest (AC) charge rate 16amps but by morning they are 98-100%. Another battery bank is in the future but until then I have to make do with what I have. Thats why I'm asking questions on how to get the max yield out of the system i have because I don't think I am right now. Like you said, the PV's are probably getting throttled back currently. I will be adding more load to the system this weekend.

This works for me, logs instantenous, daily, monthly, yearly etc.can be viewed remotely, turn off and on etc..

Just found this amazing item on AliExpress. Check it out! US $17.32 30%OFF | TUYA APP WiFi Smart Circuit Earth Leakage Over Under Voltage Protector Relay Device Switch Breaker Energy Power kWh Meter 63A

https://a.aliexpress.com/_Ewjzp2P

If your battery is 98% by morning...then the generation from pv has no where to go..unless your daytime loads. WhY not limit the inverter charging from grid at night to say 1 or 2 hrs...that way..your battery would be below 30% by morning and thus have room to accept incoming harvest from the panels.

You can use another unit of the tuya breaker i posted earlier and install at AC input of inverter and programm set times for it to allow AC through to charge inverter.

 

[Wescottpower]

3000kwhr/month? did your utility used to send you holiday thank you cards each year?

If not, they should have!!!

Nope not even any lube...

 

[Wescottpower]

This works for me, logs instantenous, daily, monthly, yearly etc.can be viewed remotely, turn off and on etc..

Just found this amazing item on AliExpress. Check it out! US $17.32 30%OFF | TUYA APP WiFi Smart Circuit Earth Leakage Over Under Voltage Protector Relay Device Switch Breaker Energy Power kWh Meter 63A

https://a.aliexpress.com/_Ewjzp2P

If your battery is 98% by morning...then the generation from pv has no where to go..unless your daytime loads. WhY not limit the inverter charging from grid at night to say 1 or 2 hrs...that way..your battery would be below 30% by morning and thus have room to accept incoming harvest from the panels.

You can use another unit of the tuya breaker i posted earlier and install at AC input of inverter and programm set times for it to allow AC through to charge inverter.

Thanks for the link, doesn't look like they have a 100amp model for split phase tho. I have a 100amp feed going to my inverter for AC in (not that I use all of it) but would want to size accordingly especially being a china component. I think what I'm going to try is the Emporia 16ct model, put the main CT's on the inverter AC in and the circuit CT's in the subpanel. This way I can see when the inverter switches between AC and PV mode and I should be able to track the inverter output via the difference.

I'm also going to turn off my AC battery charger for a while to see if that boosts output on the inverter meter. I don't have a lot of confidence in that Inverter display tho.

Thanks for all the replies and info, I'll keep you posted once the Emporia system gets hooked up.

 

[RCinFLA]

Common mistake is not realizing that any PV generated power has to go somewhere.

Choices are, supplementing AC output loads, charging batteries, pushing to grid, or load dump like hot water heater as last resort.

Excess potential PV power is just allowed to dissipate in PV panels by SCC allowing operating PV input voltage to rise above Vmp for PV array. Rising to Voc of PV array yields zero output from panels.

 

[Crowz]

Common mistake is not realizing that any PV generated power has to go somewhere.

Choices are, supplementing AC output loads, charging batteries, pushing to grid, or load dump like hot water heater as last resort.

Excess potential PV power is just allowed to dissipate in PV panels by SCC allowing operating PV input voltage to rise above Vmp for PV array. Rising to Voc of PV array yields zero output from panels.

Ran into this myself often. Add more load if you want to see it make more power. It has to go somewhere for it to make power.

Even on my small system if I turn the window ac on all day in the workshop (its the only real load it has) it will show it made 3.8kw to 4kw that day.

If I don't turn the window ac on it shows it made 1.8kw to 2kw that day.

Same panels, controllers, etc.

It has to need to draw the power from the panels or batteries to make power. If it doesn't have something to use the power on it won't use it.

 

[Wescottpower]

Added more load to the sub panel and turned off AC charging this past week. That accounted for another 2-2.5kWh per day average. Looked deeper into Emporia unit and since I don't have ethernet, I won't be able to view daily use as it's all cloud based. Going to add a CT and meter to both legs of the AC in and AC out on the inverter and just record it every morning before the sun comes up. Still don't trust that meter on the LCD display of the inverter.

 

[Crowz]

Added more load to the sub panel and turned off AC charging this past week. That accounted for another 2-2.5kWh per day average. Looked deeper into Emporia unit and since I don't have ethernet, I won't be able to view daily use as it's all cloud based. Going to add a CT and meter to both legs of the AC in and AC out on the inverter and just record it every morning before the sun comes up. Still don't trust that meter on the LCD display of the inverter.

You just need wifi not ethernet but you may of just meant internet in general.

You can actually send the emporia as far as you want with the right equipment. I have one wifi system I built that has a 40 mile range.

 

[zanydroid]

You can flash alternate firmware on Emporia, probably can get local control that way.

 

[Crowz]

You can flash alternate firmware on Emporia, probably can get local control that way.

True but I prefer the use it as is since I like the interface they provide and it works from the net nicely.

Anyways if someone wants to go local only here it is :

Reverse-engineering the Emporia Vue 2

flaviutamas.com

Setting up Emporia Vue 2 with ESPHome

Setting up Emporia Vue 2 with ESPHome. GitHub Gist: instantly share code, notes, and snippets.

gist.github.com

GitHub - emporia-vue-local/esphome: Custom component for ESPHome to add support for the Emporia Vue 2 energy monitor

Custom component for ESPHome to add support for the Emporia Vue 2 energy monitor - emporia-vue-local/esphome

github.com

 

[Crowz]

 

[Wescottpower]

Well I don't have a home monitor system like ESPHome, I'm looking for a stand-alone system. I do have a PLC running my heating boiler system (controls engineer by trade). I can make a power monitor logic program using industrial CT's and voltage transducers. Not a hundred percent on the calculations for a real time monitor tho:

I'm thinking I can sample V x I =W every second, half second, or less and accumulate those samples to a register then divide that register by number of samples per hour to equal kWh's . I think I also have to sample that total every X amount of (time) and add to the previous total. Not sure if that math computes out correctly or if I need that second portion of the formula, been searching the net for power monitor formulas but nothing easy sticks out that doesn't include phase shift and power factor formulas. If this works, I can data log/graph in my boiler's HMI, and access through my phone app for the HMI via LAN.

 

[zanydroid]

Ah OK. IotaWatt is standalone, you would have to either wait for the owner to find a partner or find someone to sell theirs to you. Maybe import an EmonPi. I have an extra but I'm a hoarder :laugh:

I think you need to do high sample rate (that's what IotaWatt and utility meters does, probably also Emporia, at a significantly higher frequency than AC) to accurately compute PF, etc. Otherwise you're seeing something closer to VA and VAh

To see the algos. You might look at the IotaWatt or EmonPi source code. Hurray for open source.

 

[Wescottpower]

If I remember correctly, Allen Bradley's power monitor sampled at 25-50 msec at my last job. My processor should be able to handle 50-100 msec calculations. I have two CTs for it, need to find a voltage transducer and play around with it...