Solar for Beginners [ask your questions here]

Eleusis

https://www.boards.ie/discussion/comment/122568876#Comment_122568876

Seems about right to me for an east/west set up. You have peaked at 3.7kw with a 4kw east 3kw west. With east/west setup you will never get direct sun on all of it at the same time, so will never produce the max of each roof simultaneously. However you will get it early and later in the day.

marco_polo

Great to know everything looks ok thanks, just wasn't sure I thought maybe they might tip a bit beyond 4kw when they are both getting good light in the middle of the day but that is obviously not the optimal angle for either side. Other than that the hourly graphs look pretty much as I was expecting for 4kw east, 3kw west.

Eleusis

https://www.boards.ie/discussion/comment/122569550#Comment_122569550

Someone with more experience with east/west set up might be able to tell you if your overall is normal or not. I know(in northwest) the second half of august was raining and grey a lot) Apart from last few days. I think the south east has been much better though going on daily pv updates posted here.

bullit_dodger

https://www.boards.ie/discussion/comment/122569701#Comment_122569701

I've 6.5Kwp in exactly a E/W setup, and it's only in May/June that you'll see yourself hitting 5kw.

Friday was a pretty good blue skies day in Dublin. Max east production was at 11:05am, and then it drops off as the West array is still gaining in production which happened at 3:20pm. Yeah, your still producing some off the east, but the max total was in between the two times at 2pm. The good thing though is that you get this 4kw for a longer period than you do with a south only array.

E/W is actually the preferred orientation for a lot of solar farms for this reason that you get a lot longer production more "smoothed" out over the course of the day

Batiatus

Hi guys,can anyone recommend the best inverter for DC oversizing? I’m a qualified electrician looking to do a self install. I’m looking to put 10-12 kw of panels on the roof. Single phase supply to the house. Thanks in advance.

Batiatus

Sorry forgot to add the roof orientation is east west.

graememk

https://www.boards.ie/discussion/comment/122576338#Comment_122576338

Couple of things limit the oversizing capability

The voc limit of the inverter and total voc of the panels. Temperature also has to be taken into consideration as the colder it gets below STC the higher the voltage goes.

Some inverters allow parallel strings, which allows more current, without rising the voltage too much.

Are you looking at NC6 or NC7?

10-10-20

Hi again!

Don't forget about the input voltages and what I was saying about the panel Vmpp and the MPPT input voltage - you need your string to be lower than the limit AND you also need keep the inverter below the 25A limit. So sizing for 10 to 12kW of panels isn't going to happen on a 5.5kW inverter as the string is going to over-volt. Roughly 20% is the oversizing rule unless you have a trick up your sleeve (or you're going to go with parallel strings?).

https://www.boards.ie/discussion/2058366221/solar-installation-diy

Rain_Dog_Brian

https://www.boards.ie/discussion/comment/122572583#Comment_122572583

That's a very helpful set of graphs that can help newbies understand general expectations. I have a dual array S (6 panels = 2.4kWp) and W (4panels = 1.6kWp) and would love to be able to understand the power off each array, but the Huawei FusionSolar app doesn't show each string. Is it an app that gives you that data?

con747

https://www.boards.ie/discussion/comment/122576508#Comment_122576508

Input your system details into the below website to get a fairly good estimate of yearly production, enter each string separately.

https://re.jrc.ec.europa.eu/pvg_tools/en/tools.html

newhouse87

IS vat off panels only for installers? Don't qualify for grantbso DIY to an extent may work out cheaper?

graememk

0% is only for supply and fit, if you just buy the stuff it's at 23%

newhouse87

Can get ground mount and 18x 440w jinko panels and5kw solis hybrid inverter for5k including vat. Best quote is 9700 from installers. Most over 11k. Just need a solar nixer guy to guide me and wire. Might cancel my deposit.

newhouse87

Anybody know anything about offgridkit in banbridge?

Screenshot_20240903_135730_Chrome.jpg

idc

https://www.boards.ie/discussion/comment/122576422#Comment_122576422

The output below STC is something often forgotten, the german division for my inverter produce a great excel worksheet where you fill in panel specs and it then displays if number and configuration of those across two MPPTs is valid (handles case of insufficient panels and too many) For the spreadsheet they picked either -25 or -30 as the lowest temperature possible for germany when working out max voltage.

Cal04

Just got 16 panels and a battery.

SSo I want to charge battery between 2-6 am with Energia. So am I right on this?

Charge the battery cheaply at this time, use the battery during the day and if more needed, it comes from the panels. Then whatever is left over, goes to the grid which you are paid for. Am I right or totally wrong?

Batiatus

I’m not sure yet, I must look into the NC7 route., future proofing etc. I heard the NC7 application process can be a bit drawn out?

Cal04

Anyone?

Cal04

Anyone?

tommythecat

https://www.boards.ie/discussion/comment/122579345#Comment_122579345

That's what I do. As long as you are on the cheap ev rate.

Cal04

Apologies, my question is more the second part, is that what happens? That the rest goes to the grid where you earn/goes as credit into your account.

graememk

https://www.boards.ie/discussion/comment/122580997#Comment_122580997

Yeah export is export, if it comes from solar or battery it's all the same

tommythecat

https://www.boards.ie/discussion/comment/122580997#Comment_122580997

Yes if the battery is charged and you are generating more than you need to run the house then the surplus is exported to the grid to earn FIT.

loyatemu

your battery won't discharge to the grid unless you set it up to. I have a 5kw/h battery which I charge up during the EV slot. It then gets topped up by solar during the day and any spare solar gets exported. Most days I don't import any more electricity and the battery is mostly empty by the time 2am rolls around so I don't have it setup to discharge.

As the solar production decreases going into the winter I expect the battery won't last the day and I'll start importing later in the day. It might be worth setting the battery to top up from the grid again before the peak slot (5pm-7pm).

Grumpypants

I opened up my fuse box to try to find the CT clamp for the EV charger to understand why it isn't picking up the export.

There is only one CT clamp from the charger and I can see it in the fuse board. Pictures below. There are two, one looks wireless? Perhaps the solis one. And one connected to the Charger.

I guess what I am wondering is if ?

Is this the CT clamp that just balances the load so it doesn't overload the house and has zero impact on the solar charging?

Is this the correct Solar one but not working…Or is it just on backwards and reading incoming not export?

The black and white wires on the left are from the charger.

this is the clamp they are attached to

And finally, you can see it on the cable in there (the green arrow)

10-10-20

https://www.boards.ie/discussion/comment/122581865#Comment_122581865

Hard to know if there isn't a way of telling what the EO charger sees. I'd pull the CT cables out of the charger and see if the problematic behaviour changes.

What model or part number is that larger CT? Not sure that it's too smart having that battery powered in such a tight spot, but maybe it is.

graememk

Ct wouldnt be wireless., Its likely you just dont see the wire

The only "wireless" one is the harvi. And the CT itself isnt wireless in that case.

Grumpypants

Possibly it's all very tight , it might just be some kind of spacer too. It's not connected to the charger either way 🤣.

How do you open a CT clamp? I'm a bit nervous of sticking a screwdriver in there but if you just need to gently force it open I might try take it off and see.

Grumpypants

This is the screenshot from the app when it was plugged in. It's reading the site consumption, the charge rate , but 0 for solar generation.

10-10-20

I googled EO ct clamp and this came up...

Looks like yours and I think the clamp is on right as long as the power is coming in to the board via the big 16sq cable.