Solar PV battery options

E30M3

unkel wrote: »

You can get them for around €750 brand new, incl. VAT. You'd need to pull a few strings for that though and use a trade account. But maybe try sell on FaceBook, plenty of people over there love overpaying for stuff. Put them up for €899 and see what you get

Sounds ambitious, especially around these parts. €600 would seem to me to be a good price to achieve and even at that I'd say most people would opt for new for €150 more, just my opinion of course.

DrPhilG

graememk wrote: »

Can't mix and match different battery makes, different communication protocols etc

Plus I need to fund the expansion, and selling 4.8kWh for even €1200 is good business when I'm replacing it with 20kWh for €2700.

E30M3 wrote: »

Sounds ambitious, especially around these parts. €600 would seem to me to be a good price to achieve and even at that I'd say most people would opt for new for €150 more, just my opinion of course.

True, but as unkle said you need to do a fair bit of haggling and have a trade account to get that price.

Most people not in the know would pay close to €1k for a new Pylontech. I think the original one I got was just over that, but discounted by the grant.

As I say I was watching them on ebay in the UK and second hand regularly sell for £7-800.

DrPhilG

With regard to batteries, is the grant only available on new batteries or could you claim it against a second hand one like you can with a car charger?

Friend of mine is looking at a solar install shortly and if he could use the grant against one of my batteries it would work well.

unkel

DrPhilG wrote: »

selling 4.8kWh for even €1200 is good business

I wouldn't accept a cent less if I were selling. Should be easy enough to achieve, despite your location.

championc

First of all, I would strongly suggest to go initially with Unkel's advice and list at €899 on Facebook Marketplace and see what offers you get.

Secondly, what is the discharge rate you hope or need a system to deliver (at night when there is no solar generation ?

DrPhilG

championc wrote: »

Secondly, what is the discharge rate you hope or need a system to deliver (at night when there is no solar generation?

Discharge rate of the battery overnight? The base load tends to be around 3-400w but I do sometimes run the dishwasher etc overnight which could peak at 2-3kw total. There is also a well water filtration system that flushes around 2am and gives short bursts of high draw.

championc

DrPhilG wrote: »

Discharge rate of the battery overnight? The base load tends to be around 3-400w but I do sometimes run the dishwasher etc overnight which could peak at 2-3kw total. There is also a well water filtration system that flushes around 2am and gives short bursts of high draw.

So your system can then be designed around an ME3000 with it's 3kW output. So you could plan buying an ME3000 and a second non-hybrid inverter, and you could still consider selling your existing hybrid at some stage.

You can also plan for a BMS sized to just 3kw too, and doing a 2p16s battery pack makes sense too.

DrPhilG

championc wrote: »

So your system can then be designed around an ME3000 with it's 3kW output. So you could plan buying an ME3000 and a second non-hybrid inverter, and you could still consider selling your existing hybrid at some stage.

Can the ME3000 cope with a 5.6kWp array?

graememk

DrPhilG wrote: »

Can the ME3000 cope with a 5.6kWp array?

Its just a storage inverter, monitors the grid and takes any excess, Or discharge when it sees import (i find that it likes to sit at about 10w import, but that's small enough to be measurement error on my end.


Max ive seen mine charge at is 3.2kw.

An option would to have 2 16 cell packs, one on the hybrid and one on a storage inverter and that would be able to give you a max charge rate of 6 kw.

Ballylad

I have a 4kw SMA inverter with 5kw 280w panels facing SSE, I recently put down foundation in garden for a 14 panel 390W panels ground mount (sun fixings ballast system) 5.46 kw facing SSE.I have a heat pump, 2 EVs with Zappi charger, granny flat electricity load, night rate meter.
I am reading these posts with interest as some of you are expanding in a similar manner. I was thinking of leaving current SMA inverter and panels and getting a Fronius 6kw inverter for the new panels. These have export limitation to satisfy ESB 6kw limit. Have any of you any suggestions on how I should proceed?, or any installers that have installed something similar?. Is a battery worth it when feed in tariff is imminent?. I will not be getting any grant for this expansion. Any comments welcome.

DrPhilG

graememk wrote: »

Its just a storage inverter, monitors the grid and takes any excess, Or discharge when it sees import (i find that it likes to sit at about 10w import, but that's small enough to be measurement error on my end.


Max ive seen mine charge at is 3.2kw.

An option would to have 2 16 cell packs, one on the hybrid and one on a storage inverter and that would be able to give you a max charge rate of 6 kw.

Ah gotcha. Didn't realise the Sofar was only for battery management.

So the theory would be to keep my 5kw Solis for now, with the panels feeding. Then the Sofar connects to the main fuse board? And the battery connect to the Sofar.

championc

Correct. The Sofar has DC batteries connected into one side and the AC grid out of the other side.

The Sofar needs to be able to detect both PV output and grid input / output. So wherever you plan to install this, just be aware of the cable runs required. Cat5 cable should be fine.

graememk

championc wrote: »

Correct. The Sofar has DC batteries connected into one side and the AC grid out of the other side.

The Sofar needs to be able to detect both PV output and grid input / output. So wherever you plan to install this, just be aware of the cable runs required. Cat5 cable should be fine.

Yep for the CT to measure the grid import/export

Could be connected to your garage board.

*Will need a rec to connect it though.

sebdavis

DrPhilG wrote: »

With regard to batteries, is the grant only available on new batteries or could you claim it against a second hand one like you can with a car charger?

Friend of mine is looking at a solar install shortly and if he could use the grant against one of my batteries it would work well.

Grant is only on new

slave1

sebdavis wrote: »

Grant is only on new

Where does it say that? Mate of mine got the grant with a used inverter, can't see why a used battery would be any different. He actually got a used battery too along with a brand new one but I couldn't tell you what battery photos were uploaded for the grant

sebdavis

graememk wrote: »

Can't mix and match different battery makes, different communication protocols etc

Thanks, so I have a 2.6kWh GivEnergy battery. So if I wanted to upgrade this system I can only buy GivEnergy batteries?

But if I take out the GivEnergy and just connect the batteries as discussed here they should* work with the current GivEnergy 5.0 invertor?

sebdavis

slave1 wrote: »

Where does it say that? Mate of mine got the grant with a used inverter, can't see why a used battery would be any different. He actually got a used battery too along with a brand new one but I couldn't tell you what battery photos were uploaded for the grant

Im sure I seen it as part of the initial Q&A the equipment had to be new. Could be wrong

graememk

sebdavis wrote: »

Thanks, so I have a 2.6kWh GivEnergy battery. So if I wanted to upgrade this system I can only buy GivEnergy batteries?

But if I take out the GivEnergy and just connect the batteries as discussed here they should* work with the current GivEnergy 5.0 invertor?

Really depends on the inverter. If it has a custom/manual profile it's likely they will work.

sebdavis

graememk wrote: »

Really depends on the inverter. If it has a custom/manual profile it's likely they will work.

This is it: https://midsummerwholesale.co.uk/pdfs/giv-hybrid-datasheet.pdf

If not, am I correct you could buy a second invertor and connect up to the system? then connect this one to the new battery arryay

championc

I think grants are all about signoff by the SEAI installer. So there is absolutely nothing as far as I know about the condition of the equipment used - it's more about how it is installed.

For a Givenergy Inverter, it may well be that they will only certify the connection of a Givenergy battery pack and therefore, could end up invalidating a warranty in addition to being unable to get them to "play" together

So to go the DIY route, the inverter MUST have the ability to allow you to enter custom parameters. You cannot rely or expect an Inverter to use Canbus to enable the devices in unison

sebdavis

championc wrote: »

I think grants are all about signoff by the SEAI installer. So there is absolutely nothing as far as I know about the condition of the equipment used - it's more about how it is installed.

For a Givenergy Inverter, it may well be that they will only certify the connection of a Givenergy battery pack and therefore, could end up invalidating a warranty in addition to being unable to get them to "play" together

So to go the DIY route, the inverter MUST have the ability to allow you to enter custom parameters. You cannot rely or expect an Inverter to use Canbus to enable the devices in unison

So could I buy a new invertor with batteries and hook up? leaving the current system in place?

championc

sebdavis wrote: »

So could I buy a new invertor with batteries and hook up? leaving the current system in place?

Why would you think you couldn't ? But what are you looking to achieve ? Define your output goals and design the system to your needs

DrPhilG

Back with the questions...

OK so as I understand it, I have 2 options. Even though I may not need all of this right now, I'm just future proofing.

Edit, just summarised for simplicity.

Option A - hybrid inverter with batteries, plus additional inverter for extra panels in time.

Option B - 2 non hybrid inverters, plus Sofar ME3000 to manage batteries.

Any thoughts on the pros and cons of each? Option A may be cheaper, as only need 1 additional inverter whereas a option B needs 2. But B would mean that I could split my batteries between the Solis hybrid and the Sofar, giving me double the charging capacity as each can charge their respective batteries at 3kw. I'm guessing its more complicated though as you need to ensure that both inverters are reading the export correctly, and also deciding which one charges first.

championc

DrPhilG wrote: »

Back with the questions...

OK so as I understand it, I have 2 options. Even though I may not need all of this right now, I'm just future proofing.

Edit, just summarised for simplicity.

Option A - hybrid inverter with batteries, plus additional inverter for extra panels in time.

Option B - 2 non hybrid inverters, plus Sofar ME3000 to manage batteries.

Any thoughts on the pros and cons of each? Option A may be cheaper, as only need 1 additional inverter whereas a option B needs 2. But B would mean that I could split my batteries between the Solis hybrid and the Sofar, giving me double the charging capacity as each can charge their respective batteries at 3kw. I'm guessing its more complicated though as you need to ensure that both inverters are reading the export correctly, and also deciding which one charges first.

You've a bit of a typo error in there on option B. If you had B, the batteries are only connected to the ME3000 but are charged by either or both non-hybrid inverters

DrPhilG

championc wrote: »

You've a bit of a typo error in there on option B. If you had B, the batteries are only connected to the ME3000 but are charged by either or both non-hybrid inverters

I thought that was what I said/meant? Or you mean I should have said the Sofar connected to the batteries, rather than just to manage the batteries?

Or have I confused myself again lol.

championc

DrPhilG wrote: »

I thought that was what I said/meant? Or you mean I should have said the Sofar connected to the batteries, rather than just to manage the batteries?

Or have I confused myself again lol.

Yep, you're confused again.

The ME3000 is a storage inverter. It's essentially an equivalent of a Tesla Powerwall - a controller linked to a battery bank

So an ME3000 is like a solar hybrid inverter without any connections for Solar PV - just DC battery power and AC grid power, flowing back and forth

DrPhilG

championc wrote: »

Yep, you're confused again.

The ME3000 is a storage inverter. It's essentially an equivalent of a Tesla Powerwall - a controller linked to a battery bank

So an ME3000 is like a solar hybrid inverter without any connections for Solar PV - just DC battery power and AC grid power, flowing back and forth

OK now I'm confused about being confused.

What you just explained is what I meant. The 2 solar non-hybrid inverters manage the PV, and the Sofar & batteries sits in line between the PV inverters and the grid to connect/control/manage the battery, (as a controller linked to a battery bank).

DrPhilG

Using the medium of poorly scratched out drawings done on a phone...

This is my (possibly wrong) understanding of Option B.

DrPhilG

And Option A

championc

Both drawings are correct