Solar for Beginners [ask your questions here]

idc

The problem with NC6 is ESBN don't allow export limitation they look purely at the size of all inverters connected to the grid😕 Most people think yeah i'll just set my inverter to limit to 5kW even though thats against the rules for NC6. Whether they'd ever check or realise who knows

NC7 on the other hand does allow export limitation!

bassy

Hi all I know nothing about solar panels etc but I'm wondering if you can advise me on one for to keep my 12 volt battery charged in my shed,can you link me to a suitable one that would do the job, thanks.

ELM327

https://www.boards.ie/discussion/comment/120831507#Comment_120831507

the gas thing is you can do export limitation on other certifications (EG NC7) but not NC6 for some reason.

bullit_dodger

https://www.boards.ie/discussion/comment/120835467#Comment_120835467

I guess the logic is that the demographics of the people who want/need a NC7 would generally be different from the people (Joe Sixpack) who'd have an NC6. The NC7 folks who are forking out €1000 for the initial consult would tend to be a bit more knowledgeable than your average consumer. That's not to say that people on NC6 are dumb. I'm on a NC6 and I think I'd know how to set an export limit correctly :-) .... but I guess you know what i mean.

ColemanY2K

would one of these sheds do the trick to house batteries and the inverter? it would be for less than 5 years until i get the garage built, then the plan would be to transfer the kit.

10-10-20

https://www.boards.ie/discussion/comment/120865686#Comment_120865686

It's a tinder-box in the event of an electrical fault, but as long as it's dry and the inverter is mounted to a fireproof backing board and the wiring is protected and certified, then it should be fine.

slave1

You might find a large external comms box second hand, I remember some being mentioned on this forum while back

ColemanY2K

https://www.boards.ie/discussion/comment/120865875#Comment_120865875

ya i saw it advertised online. its huge and dog to shift.

a small DIY steel framed shed might also be an option given what 10-10-20 said. the question is would it become an oven in the summer effectively shutting down the inverter at a time when it should be producing to the max.

10-10-20

https://www.boards.ie/discussion/comment/120866305#Comment_120866305

You could easily ventilate it using fly-screened vents on either side, top and bottom. Easy enough project. Reflective-foil insulation on the roof would keep much of the heat out too.

Paint it like a tardis inside and admire the flashing LED's... 😆

ColemanY2K

https://www.boards.ie/discussion/comment/120866433#Comment_120866433

true enough, you've given me plenty food for thought.

micks_address

https://www.boards.ie/discussion/comment/120802304#Comment_120802304

Rcbo replaced today. Hopefully should be sorted re tripping

10-10-20

https://www.boards.ie/discussion/comment/120867537#Comment_120867537

Hopefully for you, but your problem cursed me today! I had two RCD trips early this morning while it was raining and I was thinking about your situation - so I isolated the solar and left it for a few hours. No further trip then until lunch and I was thinking that I'd have to climb up onto the roof and test the inverters... but then at 2pm it dropped again, even with the panels isolated, so I was relieved in some way. The RCD wouldn't set at all this time, so I went about isolating circuits and when I disconnected the feed to the pond it reset ok.

I just found the culprit: sealed power supply to the UV filter was cracked. At least it's not the solar!

ColemanY2K

i've been trying to do a bit of maths to figure out the potential saving that could be made had i a battery big enough to get me through the day rate period without drawing power from the grid. i signed up to the flogas community plan last week.

so the way i look at it is like this.....

33.38c minus 14.75c = 18.63c which is the difference between night rate and day rate. supposed i could charge up a battery large enough (my inverter is limited to 3kW/hr which equates to a max 27kW battery over the course of the night rate period) to get me through the day rate period without drawing power from the grid then that would be a saving of 18.63c x 15kW (average consumption on day rate) = €2.79 per day or circa €1,019 per year against having to use solely day rate period.

my workings are crude and don't take into account seasons, standing charge or CEG however are my numbers in the right ball park? If so then that would mean the repayment period for a battery, lets say 4 x pylontec 4.8kWh @ €1400 a piece is enticing. Even more so if you DIY the battery.

P.S. there's no mention of a fair usage policy in the terms and conditions emailed to me.

con747

https://www.boards.ie/discussion/comment/120868931#Comment_120868931

Take into account the battery charge discharge losses of up to 15-20% afaik in your numbers.

ColemanY2K

https://www.boards.ie/discussion/comment/120868968#Comment_120868968

will do, cheers.

its just a rough and ready exercise however if my numbers are in any way correct then the tariff incentivises people to create a large battery bank.

10-10-20

https://www.boards.ie/discussion/comment/120868931#Comment_120868931

Gary did a video on that this week and wrote a calculator which should give you an answer.

https://youtu.be/3vwDrfuXyik

I have not played with the calculator, so can't confirm for sure, but do let us know.

ColemanY2K

https://www.boards.ie/discussion/comment/120868994#Comment_120868994

wooah gary is incredible. he had me sold on batteries after 25 seconds lol.

we could really do with dynamic pricing models like the uk has.

ColemanY2K

That's a really invaluable tool. Playing around with Gary's calculator indicates a 10kW battery is likely to be the sweet spot for my gaf which consumed an average of 15kW per day in 2022 and 2023 to date. I'll be moving into a new bigger gaf shortly which is expected to consume a max of 20kW per day.

The calculator suggests the soon-to-be built 8kW array facing due south combined with 10kW battery would cover my needs for the bulk of the year with a sizeable FIT payable for energy generated during that period.

The calculator will have to be revisited if, or when I should say, EV(s) appear on the driveway.

It's been a really useful tool, thanks for posting it 10-10-20 👍

10-10-20

https://www.boards.ie/discussion/comment/120869374#Comment_120869374

OK, must play with it myself then too!

https://garydoessolar.com/utilities/dailymodellingutility/

DC999

https://www.boards.ie/discussion/comment/120869374#Comment_120869374

EVs don't really change it. They should charge on cheapest night rate too - that's at the point when deemed export is gone for D/N meters.

Charging a large EV battery from a smaller home battery should be rare and used for when the house battery is full so it will 'overflow' into the EV.

Sure, you uses more power with a new EV. But on cheap night rate.

unkel

I've followed Gary since he started on YouTube and I came across him by accident. Personally I don't think I've learnt much from it, but he is about the best channel out there, very well researched and presented concisely and in simple language. Only clever people can do that. And I can imagine he put quite some time in setting up that tool.

Highly recommended for anyone interested in the field

I can only wish we had something like Octopus Agile over here (or similar deals like in the USA and the Netherlands that I'm aware of). Not only because it is vitally important in the transition to renewables, but also on a personal level as I've invested heavily in being ready for this sort of future and the pay back on my system is hugely shortened by playing the excess / shortage game

10-10-20

Midsummer have Trina 430w panels at 153 ex VAT.

https://midsummer.ie/buy/trina/trina-vertex-s-plus-430

Seems the glut in Europe is driving many of the panel prices down.

https://www.pv-magazine.com/2023/07/19/european-warehouses-currently-host-40-gw-of-unsold-solar-panels/

ColemanY2K

https://www.boards.ie/discussion/comment/120876252#Comment_120876252

That could explain why GWL's 410w elerex panels have dropped to €101 per panel incl. VAT (delivered) if you bought a pallet of 36. They were about €150 a piece a few months.

It could also explain the recent drop in battery prices as well.

graememk

Cost of shipping containers are dropping drastically too.

unkel

https://www.boards.ie/discussion/comment/120877058#Comment_120877058

Just as well. Cost of a 40' from China to Dublin had gone from $4k to $20k in just a few years. Insane. Although a container can take 800 panels, so even at the top that was just $25 per panel

micks_address

Hi folks,

Wondering what's the best solution for this..night before last night needed to charge the car for 5 hours. Set it to charge from 2am to 7am on the zappi

Also set the home storage battery to charge between 2am and 4am as usual. In the morning the car had charged but the home battery was flat. It had charged between 2 and 4 and then drained into the car. That wasn't the worst thing in the world but how can you avoid the battery drain? I could have set the home battery to charge from 2 to 7 and I usually never really charge outside of the the 2 hour night boost tarrif with ei but be good to have a solution

Thanks

Mick

10-10-20

https://www.boards.ie/discussion/comment/120877237#Comment_120877237

Can you set a no-discharge period on the inverter for the night hours?

micks_address

https://www.boards.ie/discussion/comment/120877275#Comment_120877275

The only way seems to be to set it to charge for the period, then even when it's full it won't discharge..it's an edge case for me...

con747

https://www.boards.ie/discussion/comment/120877341#Comment_120877341

If this is any use to you https://myenergi.info/stop-your-zappi-draining-your-dc-battery-t5022-s20.html

bullit_dodger

https://www.boards.ie/discussion/comment/120877341#Comment_120877341

How's your powershell? Get the APIkey from the Givenergy website and then have a script to set the maximum discharge rate to (say) 0 watts for the time you want and then the battery can't drain into the car.

With Powershell you could have your laptop fire up from sleep at say 4am set your discharge levels and then shutdown. Then at 7am your laptop fires back up and does the reverse, put things back to normal.

Another alternative way is set the battery reserve at 3am to 99%, and then reset it back at 7am(?) to 4% and it wont' discharge below 99% for the period.

Feel free to IM me for the powershell as I've played with it. (it's easy, even for a complete beginner - you just have to cut-n-paste your details/key into the 15 lines of code)