Solar PV Hints, Tips & Troubleshooting

DrPhilG

Well I've reached the point of driving everyone nuts on the PV quotes thread, and since I now have my system installed and running my endless questions no longer belong there.

So I figured I'd ask here, and also provide a home for others in the same boat, with general questions and advice on managing post-install.

My first question (of many) is how do people best manage their production in order to reduce grid export? Despite being overcast and miserable a fair bit of the day, I've produced 24kWh so far today, but ended up exporting 11.

Not too bad when we're home, as the wife did a few loads of washing and drying, put on the dishwasher etc.

But we're both at work tomorrow so other than a timed or remotely activated washer/dryer run we would end up exporting a lot more.

Extra battery capacity or a water diverter would help, but they don't tend to justify their costs in the long term.

Grumpypants

What size system did you end up with?

DrPhilG

Grumpypants wrote: »

What size system did you end up with?

6.2kwp JA panels
2.4kWh PylonTech battery
5kw Solis hybrid inverter

Grumpypants

Nice, hopefully a feed in tarrif comes soon to help with the excess heading to the grid.

unkel

Good thread!

As for tricks, you missed one there, DrPhilG. When I saw the picture you posted of your main house I could not believe the installer placed the landscape row right in the middle of your roof height wise. Preventing you from adding another row of panels below or above the current row in future. Why?

DrPhilG

unkel wrote: »

I could not believe the installer placed the landscape row right in the middle of your roof height wise. Preventing you from adding another row of panels below or above the current row in future. Why?

I've got 20 panels and 6.2kWh already, I don't see me adding any more in the near future.

I requested the vertical and horizontal centred position for purely aesthetic reasons.

Garage had to be centred to future proof against possible planning inspection, so I decided to keep the house panels in the same layout.

Also if I really wanted to add more it would be less than a day's work to move the originals and squeeze the more in.

unkel

Yeah it wouldn't be a huge job to move them, fair enough.

And to be honest, I am very jealous of your house. And garage! Beats my small 3 bed semi in a Dublin suburb hands down all day long

But you might be wrong about not adding more panels in future. Your setup is as easy and as cheap as it comes. Someone with access to cheap (trade price) value parts could add a 310wp panel for about EUR120 including fitting materials DIY. This produces 310kWh per year ball park south facing on the east coast (a bit less where you are and not south facing), which even at a super low 5c/kWh FIT, would give you a return on investment time of about 7-8 years. Much much better than regular savings sitting in the bank and much better for humanity (these figures are not taking into account a potential upgrade to 3 phase electricity or a potential need for upgrading your inverter)

DrPhilG

Fair enough I'll cross that bridge when I come to it.

For now, I have more pressing issues:

1 - excessive exporting. If I have another day like yesterday in terms of production, but we're not home, I'll probably export 15kWh or so. That's a crying shame. Any suggestions? My wife is seriously bending my ear now about not having added the water diverter, lol.

I could still add the cheaper diverter for about €200. Or I could add another 2.4kWh battery for €900.

Although once the Zappi connection issues are resolved I'll be able to charge the car from about 5pm onwards. Or I could just use the granny charger.


2 - anyone have experience with Zappi/hub connection? I did pair them up, but the Zappi isn't getting the message. But the hub is, as the app does show grid export. So I'm not sure if the problem is with clamp location or Zappi/hub communication.

The installer is coming back this week to try again to troubleshoot.

rx8

I work shifts, so I find it easier to manage excess as I'm at home when I'm exporting a good bit of the time. Some days the meter doesn't move at all. Hopefully when the zappi goes in it'll use all or most of the afternoon excess. Happy with the setup and results so far anyway. Electric bill is less than half of what it was this time last year.

DrPhilG

rx8 wrote: »

I work shifts, so I find it easier to manage excess as I'm at home when I'm exporting a good bit of the time. Some days the meter doesn't move at all. Hopefully when the zappi goes in it'll use all or most of the afternoon excess. Happy with the setup and results so far anyway. Electric bill is less than half of what it was this time last year.

Same here, only been a few days but I'm very surprised at how good the production has been.

Only used about 6kWh at day rate from the grid in the first 4 days of use, previously I would have averaged about 10. I haven't been checking my night usage but that will be well down too as we've been doing washing, drying, dishwasher for free during the day instead of for 8c at night.

We work office hours but the washer has a timer delay and the dryer has remote operation.

25.3kWh generated yesterday with only fleeting spells of clear weather. 4.6 so far today despite total cloud cover all morning.



I think the south/west split will serve me very well.

garo

Yes the south + west combo seems to be serving you very well. Production peaking at 6pm.

Exporting to the grid is unfortunately something you will have to live with. In the worst(best?) days in May I ended up exporting up to 17kWh. This despite working from home, doing all the washing and even turning on the immersion by hand.
It’s your call on whether you want another battery or a diverter. Even with a large system like that you will probably not fill the second battery for four months of the year. Does your single battery run out by the time you hit the night rate? If not, it’s probably not worth it. With 10k cycles you will get 20000kWh out of the battery. At €900 that 4.5 cents per unit for the battery assuming free electricity from PV. I pay 8c for night rate so I don’t really think saving 3.5c best case is such a great saving given the extra investment.

We use a fair bit of hot water but I have a small 117l tank so it heats up pretty quickly with the 3kW immersion. Also the bottom quarter of the tank stays cold with the immersion. If you want to go the diverter route you should ideally have a large tank, 240-300litres and have a long immersion that reaches to near the bottom. Even then you will be exporting a fair bit. Heating a 300l tank from 20 to 60 degrees is 14kWh. That will cost you about 50c on the oil boiler you have and max 70c on the gas.

DrPhilG

Thanks @garo

I might have a lead on a second hand Eddi from the UK so if I can get that cheap I might go for it.

We don't burn much oil at the minute and we both actually had to use the electric shower this morning as there was no hot water.

I'll keep an eye out for a second hand battery too. Also a friend of mine who built his own self storage system from Leaf cells is considering adding more, I reckon I could get about 8kWh of cells running for the same price as an extra 2.4kWh of pylontech.

KCross

DrPhilG wrote: »

2 - anyone have experience with Zappi/hub connection? I did pair them up, but the Zappi isn't getting the message. But the hub is, as the app does show grid export. So I'm not sure if the problem is with clamp location or Zappi/hub communication.

The installer is coming back this week to try again to troubleshoot.

Was the 2nd CT clamp added to the Solar input?

Was it enabled in the Zappi menu?

Does the Zappi screen show Solar production in the top left part of the screen?

If no is the answer to any of them the installer needs to set up that clamp properly first.

The app will only display what the Zappi sends to the hub.

DrPhilG

KCross wrote: »

Was the 2nd CT clamp added to the Solar input?

Was it enabled in the Zappi menu?

Does the Zappi screen show Solar production in the top left part of the screen?

If no is the answer to any of them the installer needs to set up that clamp properly first.

The app will only display what the Zappi sends to the hub.

1 - yes
2 - yes (I think)
3 - no

He was with me on Saturday making some adjustments, but he's calling back this week during office hours as he is going to call up myenergi and/or Solis to troubleshoot if he can't figure it out himself.

KCross

Looks like he didn’t enable it in the Zappi. If he did it right it would show it in the Zappi screen

No point looking at the app for that data until he sorts that out.

DrPhilG

KCross wrote: »

Looks like he didn’t enable it in the Zappi. If he did it right it would show it in the Zappi screen

No point looking at the app for that data until he sorts that out.

Would that be easy enough to do myself? He's not back til later on this week. If it's straightforward to do via the Zappi menus I could get a headstart.

KCross

DrPhilG wrote: »

Would that be easy enough to do myself? He's not back til later on this week. If it's straightforward to do via the Zappi menus I could get a headstart.

Menu > other settings > advanced > CT inputs

CT2 should be “Generation only”

Menu > Other settings > display and sound > icons

Generation = Sun
Monitoring = On

Then go back to main screen and see if the PV generation is showing on the top left. You should see a sun with arrows pointing to the house.

DrPhilG

KCross wrote: »

Menu > other settings > advanced > CT inputs

CT2 should be “Generation only”

Menu > Other settings > display and sound > icons

Generation = Sun
Monitoring = On

Then go back to main screen and see if the PV generation is showing on the top left. You should see a sun with arrows pointing to the house.

Thanks, I'll give it a go tonight.

In other news I just wifi activated my immersion, it was killing me watching the grid export...

Generated nearly 10kWh so far and pumped half of it to the grid for free.

Immersion now on and eating up all the production and a little from the (full) battery.

DrPhilG

KCross wrote: »

Menu > other settings > advanced > CT inputs

CT2 should be “Generation only”

Menu > Other settings > display and sound > icons

Generation = Sun
Monitoring = On

Then go back to main screen and see if the PV generation is showing on the top left. You should see a sun with arrows pointing to the house.

CT2 was set to "Gen & Battery". I changed it to generation only.

The second setting was as you described.

No change after I made the switch.

DrPhilG

I tell a lie, no change is not correct.

No change in the Zappi, yes. Still blanks.



But the myenergi app has now copped on to the production.



Not 100% matching the Solis app but the myenergi updates far more often so I can understand a bit of a discrepancy.

DrPhilG

I take it a 3rd clamp will be needed between the inverter and the battery to give me that final icon on the myenergi app?

Doesn't solve the issue of why the Zappi isn't recognising the numbers though.

KCross

My guess is that the polarity of the clamp(or clamps) is wrong, so rather than give the wrong reading its just saying zero.

Do you have sight of the Solar clamp? There is an arrow on it and the arrow (iirc) should be pointing in the direction of the fuseboard if its connected correctly inside the Zappi... just flip it around so that its pointing the other way from what it is now. If that doesnt help then put it back the way it was.

Let me know how that goes.

He could also have the clamp on the wrong wire or connected to the wrong terminal in the Zappi. Unless you are willing to open the Zappi you'll need him to come back to check that. Strange he didnt get all this sorted when he added the 2nd clamp.

DrPhilG

KCross wrote: »

He could also have the clamp on the wrong wire or connected to the wrong terminal in the Zappi. Unless you are willing to open the Zappi you'll need him to come back to check that. Strange he didnt get all this sorted when he added the 2nd clamp.

Would you know which terminal is the right one if I open it up?

He ran out of time on Saturday, plus he wanted to check some things with tech support who were closed.

He is coming back later in the week.

DrPhilG

Edit, I opened it.

DrPhilG

KCross wrote: »

Do you have sight of the Solar clamp? There is an arrow on it and the arrow (iirc) should be pointing in the direction of the fuseboard if its connected correctly inside the Zappi... just flip it around so that its pointing the other way from what it is now. If that doesnt help then put it back the way it was.

Question though, if the clamp was the wrong way around, wouldn't the app be reading wrong too?

PS if I change the CT2 setting to AC battery, I get the battery icon but not the generation.

I think the CT2 clamp he has placed is reading both the combined flow of generation and battery, ie if the house is using 800w and is getting 400w each from the house and the battery, the icon (whether its set as battery or generation).

So I suspect he'll need to separate that single CT into 2 separate ones.

As for the Zappi failing to read either of them, who knows...

garo

Those clamps look a weird to me. I'm no expert but are these three clamp? Why is one of the clamps around both the live and neutral. They will sum to zero, no? And why is there a clamp on the ground wire? That green is the ground wire no?

KCross

DrPhilG wrote: »

Edit, I opened it.

Can you get a better view of the CT wires in the middle.... they are labelled CT1, CT2, CT3 on the board. Separate the wires and get good focus on the colours (I presume you've knocked off the power!!!). It looks very odd the way he has it done.

Could you also get a pic of one of the CT clamps itself at the other end clearly showing the colour of the wires hanging off it. He will have a joiner near the clamp somewhere as they only come with 5m of cable.


What I would have expected to see inside the zappi is one wire into each terminal... he has a pair of wires in each terminal which is odd. Cant see how that would work.


At the clamp end you will have one pair of twisted cable and he will have joined them onto whatever cable he ran to the Zappi. That twisted pair cable should go into a + and - slot in CT1, CT2 or CT3.

I cant figure out what he has done to have 8 wires coming into the Zappi. It doesnt look right to me.

Has he wired a CT clamp to a Zappi before?

KCross

Or can you just confirm the following....?

in the CT1 slot he has a blue and blue/white wire in the - terminal
and a brown and brown/white wire in the + terminal

in CT2 slot he has an orange and orange/white wire in - terminal
and a green and green/white wire in the + terminal

Is that what he has done?


Can you get a pic of the actual clamps themselves, in particular where he joins the clamp wire to the cable that runs to the Zappi. Until I see that I cant see what he has done.

DrPhilG

He has done many installations, but I'm not sure what's gone wrong here. It wasn't actually him who wired them, it was some of his team.

I'll try to get a picture of the clamp in the attic later.

On a separate note, am I correct in thinking that the Zappi V2 still only allows 2 CTs?

KCross

Zappi v2 has the ability to attach 3 clamps AFAIK.

DrPhilG

KCross wrote: »

Zappi v2 has the ability to attach 3 clamps AFAIK.

That's what I thought, but then I read that the 3 clamp option is only available on a 3 phase system. Apparently myenergi were working on a firmware update to enable the 3rd clamp on single phase but I haven't found anywhere concrete to say it has happened.

Also as for wiring, he's bringing a Harvi with him when he comes back. That will resolve any queries on that front yes?