Fronius inverter live on moonlight nights


Hi ,i have a Fronius 5 kw Primo inverter with 6.625 kw of panels, on moon lit nights as on the 3-4-5 of this month my inverter runs all night and says low PV voltage.i use a RP4 to send data to PV org and am wondering if it is possible to pull the data from my inverter on moonlit nights and send it to the extended data fields the same as i do during the day time, it already sends temp data from open weather map during the moonlit lit nights .On the 24/5 this year during the day i had very low mppt watts and voltage on both trackers 7 watts and only 66 volts, Which was a AC out put of only 26 watts and am wondering how close my inverter is to starting up using moonlight, which is after reflected sunlight, thank you all in advance Jim


Heres the specs on the 5kw inverter.
looks to be 80v start up voltage
As for pulling data off it I dont know if you can if it keeps shutting down and starting up again… if its running consistenly I don’t see any reason why you cant grab the data.

you can turn on night mode to have it run 24/7 i have that set for my consumption data

with this you can see the data on solarweb. mine hovers at 2-10vdc


thanks for the reply B-man, there is no smart meter in my system, with yours the smart meter sends consumption data to the inverter which then sends it to PV org, so my inverter is a International model, and the start voltage seems to be 70 volts , my inverter is not sending any data if the AC side of the inverter has not started, IE green light is not on, orange light is on i am looking to find out how to read the inverter data before the AC side of the inverter starts up, thanks Jim


Him Jim,

When the Fronius is in ‘sleep’ mode the API doesn’t necessarily return data on all API calls.

The script running on your PI only pushes data to PVO if the returned Status Code == 7 i.e. things are happening. This would need to be altered unless ‘Night Mode’ alters the Status Code.

I’ve got a Fronius Smart Meter so my inverter is always ‘on’. The script on my Pi does NOT push data to PVO when PAC == 0. I have found that when PAC == 0 the Inverter Temperature API call also returns ‘0’ which is clearly not the case. The inverter’s temperature rarely drops below 30C… I couldn’t see the sense in recoding 0W or 0C



Hi G, thanks for the response, what i would like to do is have the extended data when the inverter is of only orange light on, so i can see how close to starting up my inverter is with moonlight,it looks like from data on the morning of 24/5 that i may only need 5 more volts to the mppt for the inverter to start up. and then i would have output from moonlight??? well sort of as its really reflected sun light,on 24/5 there was 66 volts per mppt and i think the start up is 70 volts, wondering is the start voltage is adjuster able ? Jim


The intensity of light from the moon is more than 6 orders of magnitude lower than from the sun. If a PV array could generate power, it will be measured in milliwatts.


thank you for the info, would that be DC or AC milliwatts,as i have seen a DC solar system with a maxi miser fitted running a 24 volt water pump on moonlight nights,and as you may have seen ,i am using Jinko maximum panels on my system thanks Jim


Here’s a guy who hooked up his multimeter and a few devices to see what voltage, current and power his 1.8kW array would provide during a supermoon when directly overhead.

1.7V DC and a short circuit current of 0.11 milliamps.

This guy did same with a 3kW system:

0.3V DC and 20 microamps.

Answer: bugger all power.


thank for this,have turned on the DC volts and Watts on my inverter so all i need now is a moonlit night, thanks Jim


That should increase the cloud cover :slight_smile:


update on this,last night saw 3 volts at night ,alas NO watts-----so no possible output unless a Dc maxmiser was fitted to drive something at 12 volts.


It must have have been a bit less overcast at your end of the world last night. Cloudy and stormy here.

Perhaps a full moon closer to the equinox might produce a bit more light?


I have DC optimisers fitted to get panel-by-panel monitoring, and there is always a ~200W reduction between what is coming off the roof from the panels, and the AC power coming out of the inverter - powering up and the operation of the inverter itself consumes a few X00 watts. If the panels in aggregate aren’t generating at least 200W from the moonlight, there’ll be nothing of consequence coming out the AC side!


thanks for the info Willisave, my system has Jinko maxim panels, so has 3 DC maximizes built into each panel,have 75 of them in total, i get between, at min voltage 70 volts-- 87% off DC watts on he AC side, and at better voltages say at 11.40 today 340 volts Dc side i get + % 153 on the AC side,. my inverter will not start the AC side with less l than 70 volts on the DC side.