Omnibuswoman

i think this will be my first port of call!

where do I place the probes??

No, they are both on the same inverter. I have an app that allows me to choose how to use the batteries (to the extent that I understand what to do). I can charge them from the grid overnight at a cheap rate, then they will discharge during the day to supplement supply.

How do I check this?

Could one of you signpost me to an idiots guide to basic electrical knowledge pls? I honestly can’t have been listening in my GCSE physics class as I don’t have even the most basic understanding, beyond that multiplying voltage by amps equals power. The problem has clearly worsened the less load I have put on the system - I was aiming for @SteamyTea levels of daytime usage, and that seems to be correlated to the problem. What I don’t understand is why that is…

I could have a look at the instructions and find out if I can do that. I don’t have a clamp, and even if I did I wouldn’t have a clue what to do with it 😂

@G and J we have a Solis inverter and two 3.6kW Pylontech batteries. Our electricity supply is three phase. We have also had capability to use the inverter off-grid built in, so one of the switches is for us to disconnect from the grid and operate independently.

Hmmm 🤔 That’s quite a worry… looking back at the data I have, I’ve not had a problem of overvoltage related shut down prior to late November. Very few homes here have solar PV - we are only one of two that I am aware of. When Storm Bert passed through on 23rd Nov there was a local powercut (although my home wasn’t affected). I wonder if when restoring the power they changed something in the local supply configuration. I know from the research I did before connecting to the grid that the local supply is on its knees. The DNO were trying to surreptitiously get us to fund a local area upgrade. I will speak to our installer to ask if they’ve heard of any issues with other local people.

Thanks both. @SteamyTea that theory correlates with the power stopping when the voltage surpasses 250v, however we exported electricity all summer with no obvious issues and I would have expected that to have done the same. However I only have octopus export data for that so I can’t know what exactly the panels were doing then… @JohnMo I have two consumer units - one next to the inverter, in the workshop, and a second one in the house, maybe 15 metres away, where a very large 5 core cable comes in from the workshop. You can see the cable exiting the workshop consumer unit in the below photo.

So these show voltage but no current… I’m not sure how to interpret the voltage data. I assume that PV1 is East and PV2 West, but only because I would expect East to be higher in the morning. @SteamyTea - any thoughts? I don’t know enough about power to know what might explain this…

Caught it! See series of images below…

I think you’re right, it is live data. The numbers change when I refresh the app. What I can’t do is look backwards. I will take screenshots of the live data this afternoon at intervals, and will post up here later on.

This is all I can find. No live data for voltage.

It looks as though the information I have access to via the app is limited, unfortunately. I can’t interrogate the inverter activity other than with respect to the four main parameters, and in watts or kilowatts only.

I do have an app - Solis app. I’m not sure how to view input voltages. I’ll find out!

You guys!! Honestly, I’ll never get the house finished if I let myself get distracted with this kind of thing, which is right up my street… I will add it to next year’s Christmas present list, IF I’ve finished the house… Meanwhile, there’s clearly a problem of some kind with the West facing array. This is yesterday’s output: I haven’t yet mapped it onto the available data but the chances of that being a true reflection of what the sun was doing is nil. I’ll get onto the installation company for the issue to be investigated.

My suspicion is that the spike is what the generation should have been at that time, as the sky was (unusually) perfectly clear. However I will continue to monitor the generation data and if there are any more aberrations I will investigate further. I’ve already sent the info to the installer and asked for their view, but haven’t heard back as yet.

the graph at the top is yesterday’s Wunderground data on w/m2, which maps quite nicely on to today’s PV graph (at a lower output level as it was overcast), and demonstrates the aberration on yesterday’s pv generation graph. I’ll keep a close eye on this and will see if there are any other odd results.

Thank you @SteamyTea. You’re right that’s not far from us so likely to be v accurate. I will map the values onto a chart to see how it corresponds to the PV array output over those three dates. Where did you find the data?

this is a fairly typical graph from the export tab in the energy provider app - I wasn’t here on this day so I’ve not been drawing on the pv power at all. Not sure what the weather was that day, but looks like it was at least sunny from late morning onwards.

yes it is one inverter and two strings. It’s a simple pitched roof of around 30° pitch - broadly E/W. The East has around 3kw and the West around 5kw array. I’ve only just had the software to monitor the inverter installed so am not sure what the performance was exactly previously, however according to our feed in graph on our electricity provider app the PM has always produced more. @Russdl is correct about the orientation being slightly to the north of East and to the south of West. Based on the above I will look back at the data I’ve got for the last few weeks since the Solis app started working and will compare this to the previous feed in data that I have.

Thanks @SteamyTea This is a bit beyond my capabilities at this hour of the morning, but I will have a closer look later on.

Thanks @Bramco No I didn’t do any of the installation. I’ll continue to monitor and will ask the company that installed the inverter to have a look. I was going to contact them in any case as the batteries start charging at 22:00 despite my having set the controls to start charging at midnight. Moving the charging time makes no difference, which is annoying as it’s charging them using day rate electricity rather than our overnight 7p rate.

I’ve become very keen on monitoring the inverter function on our pv array and battery system (and monitoring our use/ToU shifting). Yesterday was a gloriously sunny day - not a cloud to be seen, so I was interested to see how the panels perform in the optimal conditions in the shortest month. We are on latitude 50°30’N and 4°W. The East facing array (3kw) performed well, but as the sun moved round to the West where we have a 5kw array, output plummeted to 200w. At 14:30 I went to the other side of the village have a look at the array from behind, and there was nothing shading it. It appeared to be in full sun and yet not performing. The only thing I could think of was that the angle of the low sun was insufficient to generate power, but that would also have been true of the East panels in the morning. There was a single spike of generation at 14:45, just after I got home from looking at the panels from a distance. Then production fell again. The house is oriented roughly 64°E / 262°W. Below is an image of the generation graph. Any ideas as to what might be impeding their function?

My parents have a spring-fed system with UV sterilisation under the kitchen sink. Annual testing keeps an eye on the level of nasties in the water (which are pretty low). Waste water is via a Klargester and soakaway. Saves a fortune in mains bills. When the summer is exceptionally dry it can cause shortages, but not out and out failure of the system. Could you not simply rely on the spring and jettison mains?