Solar PV battery options

ColemanY2K · 09-08-2022 3:40pm

https://www.boards.ie/discussion/comment/119449731#Comment_119449731

Hi JJ

I'm in a similar boat. I received planning earlier in the year and intend to embark on something similar although nowhere near as grand as to what you're planning.

The FAQ thread at the top of the Renewable Energies section is a good place to start. WRT panels there's no difference as far as I can see between the various brands. You figure out your total wattage (15 to 20 in your case) and then select whichever panel is the cheapest per watt. The one thing I would recommend regarding panels is to research the different types e.g. PERC Mono Half Cell versus Poly bla bla bla. The same seems to be the case with inverters. With a battery you'll be needing a hybrid. Which one is up to you but the most common on boards appears to be Solis. As for batteries ...well this is where a bit more research is needed. I noticed a couple of experienced posters dissing pylontech recently and perhaps rightly so. You'll need to do your own research on the matter however a good place to start would be on page 1 of this thread. Another thing to note is the feed in tariff (FIT) is now making large battery systems less appealing.

There's a couple of Irish wholesalers selling PV kit online, solartricity is one such business. I have been touch with a number of retailers on alibaba who appear to be extremely competitive. If you can wait two months for the gear to arrive then alibaba could be worthwhile option. Below is a quote I got this morning.

I'm considering ditching one of the batteries from the quote because of the FIT and because the passive house I have designed needs less than 15kw over a 24hr period (reducing battery storage from 20kw to 10kw) and the roof mounting system. That would bring the quote down to circa $8,000 (shipping will be about another 500 quid) which is give or take the same in euros. I'll build my own ground mounted unit and do all the other donkey work myself. One word of warning...the quote excludes VAT and custom duties. Best to allow the guts of 30% on top of whatever quote you receive just in case.

pv.JPG

championc · 09-08-2022 8:35pm

Max inverters permitted to be connected to the grid are

Single phase = 6kW

3 Phase = 10kW

You can oversize on panels. Best fit for batteries= twice the panels kWp

bullit_dodger · 09-08-2022 9:11pm

Isn't 3 phase export limit 11kw mate?

+1 on the oversize panels for inverters, but word of caution that there is a max voltage that you have to remember. Also with that size system you might want to be looking at 3 phase as single phase would be multiple inverters and a bit of a mare :-)

Also a thing to remember on the battery (and one that I'm sort of suffering myself with) is make sure you have adequate charging/discharging rates. My own battery is limited to 2.6Kw and while I can ask for that limit to be removed, it also voids the guarantee that they give for the 10 year timeline. Charging a 20Kwhr with only 2.6Kw would be a pain in the hoop.

ColemanY2K · 10-08-2022 11:51am

https://www.boards.ie/discussion/comment/119451329#Comment_119451329

OK... just so i understand correctly, i can have multiple inverters but only one of them is permitted to be connected to the grid? if export is capped then theoretically there's a limit to the amount of power which can be sold to the grid in a given year. i am considering upping the proposed size of the array to 15kW, a battery of 10kW and lashing whatever excess is produced back to the grid at 14c per kWh (for example) but if there's a cap i could potentially be over producing and by not having enough storage sending it to the grid for free.

have i got the above right?

championc · 10-08-2022 12:21pm

A 5kWp array can fill a 10kW battery.

Think about it - 15kW generating one third power will fill the battery in less than two hours.

The cap before being taxed via BIK is €200

IMO, It's absolutely nuts even considering something that big. Can you honestly consume 50kWh per day - about 40 during Solar hours (since you'll only be storing 10kWh) ?

You still will have ESB and the Standing Charge - and it's that that is the killer

bullit_dodger · 10-08-2022 1:31pm

+1 on what championc mentions.

We see people rock in with 50Kwhr/day or there abouts with ~7-8Kwp so if you double that you'll be close on 100kwhr/day in summer. Winter you could probably use it with a heat pump etc, but of course then you have the opposite problem of too little production when you need it most.

Unless you've some "good" (subjective) reason like a bit of crypto mining, going three phase to support 15kwp is a level that's beyond most people here. That's not to say that it's undoable, but you'll be "off script" as they say :-)

If you were thinking of a top end kick ass system, I'd probably go two strings of 12x400 watt panels, hooked into a 6Kw single phase inverter. So 9.6Kwp in panels, and then couple that to a 20Kwhr battery. Be pricey doing that battery off the shelf, but if money was no object. otherwise DIY battery. The Fit of €0.14 or so will help you, but that nonsense about €200 before BIK kicks in is sad.

Keep it single phase, but if you have experience with 3 phase, then you have access to stuff/knowledge that I wouldn't have.

ColemanY2K · 10-08-2022 3:44pm

i might considering installing three strings in order to isolate two during the very high generating season and then switch them on in the darker months...the ROI could be pitiful mind you 😂

plenty to ponder, thanks gents.

bullit_dodger · 10-08-2022 3:59pm

Your welcome!

Although if you install something......hell I'd never isolate them out. Worse case you'd get a FIT payment which you'd have to pay a Benefit in kind on, but you'd still be earning coin on the panels. Albeit lower than what it should be without that BIK nonsense.

If you're isolating them because your worried about the 6Kw export limit, most inverters can set the max to export (which naturally enough on a 6Kw is 6kw by default), if you generate more, you'll only "pull down" 6Kw into the inverter from the panels.

unkel · 10-08-2022 4:46pm

Not BIK, income tax. At your marginal rate, which for many people will be around 50% if you take social charges into account too. But there is a significant exemption. I could be wrong here but was it €400 per year? The overwhelming majority of people with PV will not export that much, so they won't pay any tax on what they get paid as a feed in tariff.

bullit_dodger · 10-08-2022 4:50pm

True - income tax would probably be a more appropriate tax than benifit in kind.....although the main point was don't isolate them out. Yes it would mean that you don't have to pay tax, but then you also wouldn't be generating as much income as you could. Seems a bit wasteful to install panels and then not use them. No?

E30M3 · 10-08-2022 7:44pm

https://www.boards.ie/discussion/comment/119454935#Comment_119454935

€200 exemption

unkel · 10-08-2022 8:33pm

https://www.boards.ie/discussion/comment/119455736#Comment_119455736

Thanks. So at about 13-14c FIT we are talking exporting roughly 1.5MWh before it's taxed. I can happily do that 😂

Ballylad · 11-08-2022 5:04pm

Hi, Looking for supplier for BYD HVM battery for my fronius hybrid inverter, seen some european websites but at least 6month wait.Thnks

jumpin jack · 12-08-2022 7:54pm

https://www.boards.ie/discussion/comment/119325115#Comment_119325115

What are Puredrives?

Thanks

con747 · 12-08-2022 7:59pm

https://www.boards.ie/discussion/comment/119465369#Comment_119465369

A brand of battery, google them. I have a couple and find them very good.

jumpin jack · 12-08-2022 8:00pm

https://www.boards.ie/discussion/comment/119407829#Comment_119407829

Hi there,

Are these CALBs available now or is there a big wait?

Thanks

jumpin jack · 12-08-2022 8:04pm

https://www.boards.ie/discussion/comment/119410557#Comment_119410557

I contacted them yesterday and they won't have stock available untill end of September and then shipping will take 2 more months.

They do have a 5Kw powerwall available for immediate shipping though.

https://eu.jakiperbattery.com/product/powerwall-battery/

They say it's virtually the same product.

jumpin jack · 12-08-2022 8:07pm

https://www.boards.ie/discussion/comment/119412094#Comment_119412094

Hi again,

Do you know if these batteries are available and from where they can be purchased?

Thanks

con747 · 12-08-2022 8:19pm

Need a spell check for that website, (Ready to ship from china facotory) 😂

graememk · 12-08-2022 9:26pm

https://www.boards.ie/discussion/comment/119465412#Comment_119465412

They are bare cells though. But bolt together like Lego. Add a bms to it and your off.

Ali express, check out off grid garage on YouTube he has build one from eve cells. But similar idea

jumpin jack · 14-08-2022 11:25am

https://www.boards.ie/discussion/comment/119225101#Comment_119225101

I think I am going to take the plunge and order from China. I have been recommended a battery supplier. Apparently they pride themselves in packing the batteries properly for international freight.Has anyone had any dealings with them?

Luyuan Fully Matched 12v Eve Genuine Grade A 280ah Lifepo4 (lfp) Cells Battery 6000 Cycles With New Terminals - Buy 12v Deep Cycle Battery,New Model Cycle,Solar Energy Product on Alibaba.com

https://www.alibaba.com/product-detail/Luyuan-Fully-Matched-12V-EVE-Genuine_1600542168457.html?spm=a2700.shop_plgr.41413.14.7596521a7MYu4Q

graememk · 14-08-2022 1:07pm

https://www.boards.ie/discussion/comment/119471126#Comment_119471126

If you trust the recommendation and are happy with it, the decision is yours. Price is a little bit steep though. Nice terminals though.

Priced these https://www.alibaba.com/product-detail/Eu-Us-Stock-Grade-A-280Ah_1600219202538.html?spm=a2700.12714957.0.0.26cf7a31QL0o8S (seller recommended by andy in the off grid garage) and 700 for shipping ( for 32 cells)

insular1 · 14-08-2022 1:51pm

Would swapping out a 4kW inverter for a 6kW hybrid be considered like for like replacement akin to changing out a socket or would it require a RECI sign off?

championc · 14-08-2022 2:07pm

https://www.boards.ie/discussion/comment/119471700#Comment_119471700

Reci sign off for what ?

insular1 · 14-08-2022 3:00pm

For electrical works. I have a reasonable working knowledge of electrical stuff but am not close to being an electrician and wouldn't want to do anything to affect house insurance. Not really up to date on what requires registered electrician sign off and what doesn't.

aleesi · 19-08-2022 2:37pm

wrong thread

poker--addict · 20-08-2022 7:21am

https://www.boards.ie/discussion/comment/119209395#Comment_119209395

I am wondering the same. Having two inverters is also a reasonable solution. My thinking is getting hybrid now and setting it up for battery means I can almost plug and play a DIY battery in time, keeping things very simple.

standard inverter now; save 5-600(?)
standard inverter now, storage inverter later (benefit of different location for storage), cost 1000 later(?)
hybrid now, cost an extra 5-600 now, potentially never use it, but plug and play battery option.

that it?

championc · 20-08-2022 7:52am

I don't think so @poker--addict . I think it was a case of spending €3600 @ €30 per month for a 3kWp system with a non-Hybrid inverter, or paying about €5k (well really €7400 and get grant back later) upfront and at install.

And he went with the cheaper, fixed non-Hybrid option.

Well that's my read of it anyway - @scunermac ?

unkel · 20-08-2022 10:00am

Hybrid 6kW inverter is about a grand more expensive now than non-hybrid. All of them hard to get too.

CoffeeBean2 · 20-08-2022 11:22am

I have 16x 200amp cells on the way from OYE Store and with the recent bad reports here regarding capacit, I'm getting ready to test each cell within the first 15 days of arrival.

I've already ordered the load tester that was recommended way back in an old thread and am now looking at a charger so that I can first put a load into each cell before testing.

Would something like the following be okay? https://a.aliexpress.com/_m02OTO4

Or would you have any better recommendations?

championc · 20-08-2022 11:27am

If your batteries are on the way, then there's no guarantee that that one would arrive on time. I bought this a few weeks ago

https://www.amazon.co.uk/gp/aw/d/B08HYY3H92?psc=1&ref=ppx_pop_mob_b_asin_title

scunermac · 20-08-2022 3:44pm

https://www.boards.ie/discussion/comment/119496559#Comment_119496559

No I didn’t go with a SAAS provider. It’s the company that works directly with one of the large energy suppliers. Their model is very fixed in that they don’t offer hybrid inverters. if you want a battery, the only option with them is to go with a Sonnen system with a combined battery and hybrid inverter, which is very expensive. From what I remember it was the same price as the cost I’m paying for the 5KW of panels and non-hybrid converter in the first place.

I decided I would go with this because I’m not convinced in the payback of a battery system given my particular usage patterns. I.e we’re home during the day most days.

championc · 20-08-2022 3:57pm

There's a lot to be said too for going SaaS and getting the 5kW of panels. Really a no brainer if you are in their area

The economics of a battery at any price level is questionable now. I'd say the only one that makes economic sense is a DIY one, especially when taking full advantage of load shifting

Gerry · 20-08-2022 10:24pm

and only if you have a good night rate.

Energy1 · 21-08-2022 10:09pm

I am looking to install a large system to take into account the lower yield in winter .

What is the best 6kW inverter that can work with battery storage? By best I mean reliable, can work with a larger PV system (8/9kW) Also what is the best battery in terms of discharge rates for over 2.5kw? Preferably one that looks good too, thanks :)

SD_DRACULA · 22-08-2022 9:34am

https://www.boards.ie/discussion/comment/119503058#Comment_119503058

I'd say the Solis 6kw 5G, many of us have it here.

https://www.ginlong.com/rhi_inverter1/1952.html

It can take 8kw of panels and charge/discharge at 5kw/100a

I think some people have 9kw of panels on it without issue once you're under the 600v per string.

I think 6G might be coming out soon too

graememk · 22-08-2022 10:42am

https://www.boards.ie/discussion/comment/119504155#Comment_119504155

Is yours sustaining 100amps for more than 10-15 minutes? Either charge or discharge.

Trying to see if I can change anything here. Temps look fine and doesn't matter if I have a fan on it or not

connesha · 23-08-2022 10:22am

Hi,

I'm hoping to sell my PureDrive (5kwh DC battery) soon. Any thoughts on what is a fair price for it?

It's 6 months old, has always been kept within the default charge limits (above 20% SOC), comes with its power cables.

championc · 23-08-2022 12:29pm

Well going by our guidance, €2.5k

I do think you could get €3k since the Puredrive has the higher throughput

championc · 23-08-2022 12:44pm

For undecided DIYers - here's 20kWh of the AliExpress CALB 200Ah cells from the PWOD / OYE stores

SD_DRACULA · 23-08-2022 12:58pm

https://www.boards.ie/discussion/comment/119510063#Comment_119510063

Well considering you can get them for €2250 new I'd say around 2k

redmagic68 · 23-08-2022 3:00pm

Anyone have the idiots guide to a battery management system?

is it difficult to alter it after the installer or is it very important to get it set up as close to possible from the get go. I think I’ll need different setting for summer and winter to maximise night rate and payback.

Further change it down the road for zappi. Don’t have a smart meter installed yet and unlikely to happen before the install unless I request it.

S' · 23-08-2022 3:16pm

https://www.boards.ie/discussion/comment/119510137#Comment_119510137

Looks a good job. What are you using to insulate the cells? Have you one or two BMS’s?

DrPhilG · 23-08-2022 3:21pm

https://www.boards.ie/discussion/comment/119511017#Comment_119511017

Pretty sure that's the packaging that the cells came in, modified for insulation.

Energy1 · 23-08-2022 4:45pm

https://www.boards.ie/discussion/comment/119504155#Comment_119504155

Thanks. What battery would you recommend?

SD_DRACULA · 23-08-2022 4:49pm

I had a puredrive in the past myself and never had any issues with it other than the cost.

I have Dyness now which are also good batteries and also some folk here use pylontechs.

BYD are also nice but not seeing many of them around.

VinLieger · 23-08-2022 8:38pm

One of the suppliers im talking with currently can only supply 2 x 2.4 batteries instead of 1 x 5.1, are there any technical downsides to this I should be aware of apart from the extra space required etc?