Solar panels and battery - any real world reccomendations?

KompuKare · 7 Dec 2023 at 19:08

AnastieByte said:
I continue to live and learn about this solar stuff almost everyday. Today, we had an emergency power cut. I expected the house to be fine and run off the energy stored in the battery as this is what my installer told me. Nope.

Im still trying to get more information but it appears that the Givenergy all in one system can power the house in a power cut. But not my inverter with separate battery. In order to do this additional transfer switch needed to be installed?

While pigs may become airborne, our cowboys actually did have "backup power during power cuts" on their website. But since they were not even to do the basics right I was always very suspicious especially since we now know that their sales people would claim anything!

I note that our cowboys are now Givenergy only and are now also MCS battery certified, which is a surprise.

Back in my opening post here I had said that MCS were by far the worst regulator:

The worst one was MCS who totally washed their hands by saying that they are standards organisation but while our installer is registered with them, they are not certified to install system with a battery. A very strange position: MCS are prominently featured in all advertising by the installer on their website, and sales process and we know from the sales manager that they never sell the plain system. That is, all their installations are with a battery but this self-regulator just fobbed us off.

I guess the much hyped MCS certification isn't retrospective.

Mercenary Keyboard Warrior · 8 Dec 2023 at 09:10

Yeah all solar installs will shut down in the event of a power cut since they need to stop the risk of exporting. Its part of the requirements for most if not all countries.

You need islanding mode, or whole house EPS (emergency power supply) or something similar.

It varies in its implementation with some installing a couple of sockets, some activating one (or more) of your circuits in your house for emergency, or the best solution whole house EPS.
Whole house EPS is the islanding in effect, it cuts you off from the grid completely and enables your whole house as normal. Obviously you need to be conscious of the amount your battery can supply in regards max output and amount of energy stored at the time of the power cut.

Its one the minor advantages with the far east based manufacturers I think in that they are more used to these situations and are therefore more likely to offer a better off the shelf system.
It cost about £1k to add the whole house EPS to my Solax system in effect.
I may not have gone for it today, its a really tricky one. The main issue being that I am often out of, or running out of house battery now by late afternoon, so in the event of an unplanned power cut I am pretty unlikely to have much in the batteries anyway.
If they are planned however, like the talk last year of potential rolling powercuts then I can easily ensure I have battery capacity saved for this window.

john_smith · 8 Dec 2023 at 09:13

My battery (Tesla) powers the home in a powercut.

RobPot · 8 Dec 2023 at 09:57

Mercenary Keyboard Warrior said:
It varies in its implementation with some installing a couple of sockets, some activating one (or more) of your circuits in your house for emergency, or the best solution whole house EPS.

Huawei have a 'Back up box' for their systems which will provide power in the event of a power cut. Not clear though whether it's whole house or some circuits/sockets.
I might have a chat with my installer.

AnastieByte · 8 Dec 2023 at 09:57

Every days a school day! As per my previous comments the installer was a nightmare. I recall very clearly laughing with him when he said in a power cut you will be fine as you have solar and a battery. "all your neighbours will be wanting to use your kettle"

john_smith · 8 Dec 2023 at 10:51

AnastieByte said:
Every days a school day! As per my previous comments the installer was a nightmare. I recall very clearly laughing with him when he said in a power cut you will be fine as you have solar and a battery. "all your neighbours will be wanting to use your kettle"

Buy a hot tap, you'll have a few brews instock :-)

Welshman · 8 Dec 2023 at 12:07

john_smith said:
Buy a hot tap, you'll have a few brews instock

or fit an outside gas shower/boiler/hot water heater. Get plenty of brews then lol

KompuKare · 8 Dec 2023 at 12:10

AnastieByte said:
Every days a school day! As per my previous comments the installer was a nightmare. I recall very clearly laughing with him when he said in a power cut you will be fine as you have solar and a battery. "all your neighbours will be wanting to use your kettle"

That's the level "ignorance" I would expect from sales people not from anyone actually doing the installation! Sales seem to be able to make any crazy claim without any sanction.

A quick updates about the problems with our system, after all the grieve and being fobbed off by both the cowboy installer and their so-called regulators I have not really done anything since August.

Just this week we moved to the Octopus Flex tariff and I set it up to charge overnight. Early results are the same as back in August with 10% to 100% taking less than 4kWh.

I have also relegated the laptop to battery monitoring duty and put it in the loft with a console cable, and that has been interesting:

When	Battery #	Cell #	Volt	Curr	Tempr	Base State	Volt. State	Curr. State	Temp. State	Coulomb		SOC % from Afore	AverageIF of charge %	AverageIF bat #1	AverageIF bat #2	Discharge Energy from Afore
08/12/2023 08:47	1	0	3288	-9240	11000	Dischg	Normal	Normal	Normal	48%	48296 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	1	3288	-9240	11000	Dischg	Normal	Normal	Normal	56%	55501 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	2	3290	-9240	11000	Dischg	Normal	Normal	Normal	67%	67142 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	3	3287	-9240	11000	Dischg	Normal	Normal	Normal	49%	48863 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	4	3289	-9240	11000	Dischg	Normal	Normal	Normal	50%	50470 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	5	3289	-9240	11000	Dischg	Normal	Normal	Normal	64%	63748 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	6	3289	-9240	11000	Dischg	Normal	Normal	Normal	59%	58911 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	7	3288	-9240	11000	Dischg	Normal	Normal	Normal	54%	53695 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	8	3289	-9240	11000	Dischg	Normal	Normal	Normal	61%	61191 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	9	3290	-9240	11000	Dischg	Normal	Normal	Normal	65%	64686 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	10	3288	-9240	11000	Dischg	Normal	Normal	Normal	56%	56355 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	11	3287	-9240	11000	Dischg	Normal	Normal	Normal	48%	48289 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	12	3289	-9240	11000	Dischg	Normal	Normal	Normal	59%	58815 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	13	3290	-9240	11000	Dischg	Normal	Normal	Normal	66%	65917 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	14	3288	-9240	11000	Dischg	Normal	Normal	Normal	53%	53036 mAH	78%	73%	57%	89%
08/12/2023 08:47	1	15	3289	-9240	11000	Dischg	Normal	Normal	Normal	62%	61945 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	0	3289	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	1	3290	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	2	3290	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	3	3291	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	4	3291	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	5	3290	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	6	3290	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	7	3289	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	8	3290	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	9	3290	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	10	3288	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	11	3289	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	12	3289	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	13	3290	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	14	3289	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 08:47	2	15	3289	-8784	10000	Dischg	Normal	Normal	Normal	89%	89083 mAH	78%	73%	57%	89%
08/12/2023 09:19	1	0	3285	-7493	11000	Dischg	Normal	Normal	Normal	17%	17556 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	1	3287	-7493	11000	Dischg	Normal	Normal	Normal	19%	19038 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	2	3288	-7493	11000	Dischg	Normal	Normal	Normal	28%	28559 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	3	3286	-7493	11000	Dischg	Normal	Normal	Normal	17%	17584 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	4	3287	-7493	11000	Dischg	Normal	Normal	Normal	17%	17140 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	5	3288	-7493	11000	Dischg	Normal	Normal	Normal	19%	19813 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	6	3286	-7493	11000	Dischg	Normal	Normal	Normal	19%	19106 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	7	3286	-7493	11000	Dischg	Normal	Normal	Normal	19%	19128 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	8	3287	-7493	11000	Dischg	Normal	Normal	Normal	19%	19352 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	9	3289	-7493	11000	Dischg	Normal	Normal	Normal	28%	28410 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	10	3285	-7493	11000	Dischg	Normal	Normal	Normal	18%	18822 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	11	3286	-7493	11000	Dischg	Normal	Normal	Normal	17%	17140 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	12	3287	-7493	11000	Dischg	Normal	Normal	Normal	19%	19352 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	13	3289	-7493	11000	Dischg	Normal	Normal	Normal	33%	33171 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	14	3287	-7493	11000	Dischg	Normal	Normal	Normal	19%	18941 mAH	47%	50%	20%	80%
08/12/2023 09:19	1	15	3287	-7493	11000	Dischg	Normal	Normal	Normal	19%	19763 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	0	3286	-7144	11000	Dischg	Normal	Normal	Normal	81%	80494 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	1	3290	-7144	11000	Dischg	Normal	Normal	Normal	80%	80250 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	2	3289	-7144	11000	Dischg	Normal	Normal	Normal	80%	79435 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	3	3289	-7144	11000	Dischg	Normal	Normal	Normal	82%	81960 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	4	3290	-7144	11000	Dischg	Normal	Normal	Normal	83%	82529 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	5	3290	-7144	10000	Dischg	Normal	Normal	Normal	80%	80250 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	6	3290	-7144	10000	Dischg	Normal	Normal	Normal	82%	81308 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	7	3288	-7144	10000	Dischg	Normal	Normal	Normal	78%	78051 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	8	3289	-7144	10000	Dischg	Normal	Normal	Normal	78%	78132 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	9	3289	-7144	10000	Dischg	Normal	Normal	Normal	80%	79598 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	10	3286	-7144	11000	Dischg	Normal	Normal	Normal	77%	77155 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	11	3288	-7144	11000	Dischg	Normal	Normal	Normal	78%	77969 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	12	3286	-7144	11000	Dischg	Normal	Normal	Normal	78%	77481 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	13	3288	-7144	11000	Dischg	Normal	Normal	Normal	79%	78702 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	14	3287	-7144	11000	Dischg	Normal	Normal	Normal	78%	78132 mAH	47%	50%	20%	80%
08/12/2023 09:19	2	15	3289	-7144	11000	Dischg	Normal	Normal	Normal	78%	78051 mAH	47%	50%	20%	80%
08/12/2023 09:59	1	0	3306	864	11000	Charge	Normal	Normal	Normal	9%	9242 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	1	3309	864	11000	Charge	Normal	Normal	Normal	9%	9395 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	2	3309	864	11000	Charge	Normal	Normal	Normal	9%	9844 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	3	3309	864	11000	Charge	Normal	Normal	Normal	9%	9242 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	4	3313	864	11000	Charge	Normal	Normal	Normal	9%	9524 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	5	3310	864	11000	Charge	Normal	Normal	Normal	9%	9434 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	6	3307	864	11000	Charge	Normal	Normal	Normal	9%	9382 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	7	3310	864	11000	Charge	Normal	Normal	Normal	9%	9395 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	8	3307	864	11000	Charge	Normal	Normal	Normal	9%	9267 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	9	3313	864	11000	Charge	Normal	Normal	Normal	9%	9818 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	10	3305	864	11000	Charge	Normal	Normal	Normal	9%	9242 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	11	3309	864	11000	Charge	Normal	Normal	Normal	9%	9216 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	12	3309	864	11000	Charge	Normal	Normal	Normal	9%	9434 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	13	3313	864	11000	Charge	Normal	Normal	Normal	9%	9870 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	14	3309	864	11000	Charge	Normal	Normal	Normal	9%	9344 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	1	15	3307	864	11000	Charge	Normal	Normal	Normal	9%	9395 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	0	3305	900	11000	Charge	Normal	Normal	Normal	77%	76815 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	1	3313	900	11000	Charge	Normal	Normal	Normal	77%	76571 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	2	3310	900	11000	Charge	Normal	Normal	Normal	76%	75756 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	3	3310	900	11000	Charge	Normal	Normal	Normal	78%	78281 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	4	3310	900	11000	Charge	Normal	Normal	Normal	79%	78851 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	5	3313	900	10000	Charge	Normal	Normal	Normal	77%	76571 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	6	3313	900	10000	Charge	Normal	Normal	Normal	78%	77629 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	7	3312	900	10000	Charge	Normal	Normal	Normal	75%	74372 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	8	3314	900	10000	Charge	Normal	Normal	Normal	75%	74454 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	9	3311	900	10000	Charge	Normal	Normal	Normal	76%	75919 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	10	3308	900	11000	Charge	Normal	Normal	Normal	66%	66104 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	11	3311	900	11000	Charge	Normal	Normal	Normal	74%	73764 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	12	3308	900	11000	Charge	Normal	Normal	Normal	69%	68622 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	13	3310	900	11000	Charge	Normal	Normal	Normal	75%	75024 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	14	3310	900	11000	Charge	Normal	Normal	Normal	74%	74014 mAH	37%	42%	9%	75%	2.1 kWh
08/12/2023 09:59	2	15	3313	900	11000	Charge	Normal	Normal	Normal	75%	74372 mAH	37%	42%	9%	75%	2.1 kWh

So that seems to be happening is that battery #1 gets drained while #2 barely gets touched. The last reading above had #1 at 9%, and #2 at 75. Average about 42% but Afore says 37% ATM.

Certainly interesting but back in August when I tried each battery on its own they too were only about 50% of their rated capacity. Never did any response from Pytes, but this seems something I should ask them about.

Anyway, posted a bit on MSE in their Green & ethical MoneySaving sub-forum (https://forums.moneysavingexpert.com/categories/green-ethical-moneysaving), but really went looking over there to see about consumer rights but that's a different sub-forum where I haven't posted (yet). Did get a suggestion about a UK solar Facegroup there - never even knew that was a thing and it is set to private so probably show up in searches - had to dust of an old unused FB account after being rejected for not having a profile image, I've now been allowed to join. Seems to be a mix of end users and installers so if nothing it may help us if need an "expert's report" for going to court.

Did not have any luck with Gtec's Expert Witness thing (https://gtec.co.uk/expert-witness-support). First tried phoning them and the receptionist said they'd get the person dealing with this - presumably our youtube star - to phone back but did say they usually only deal with solicitors. Heard nothing back so emailed them, but silence.

KompuKare · 12 Dec 2023 at 19:34

Bit of another update:
First posted about the uneven discharge on the MSE forums, and someone pointed out that when bat #1 was low saying 8% or lower, that the voltages were far too high for LiFePO4 cells:
Those were the same figures as in the last post, but for instance when battery #1 was at 9% the voltage still reads 3,313 mV.
Whereas a LiFePO4 cells and voltage table is supposed to be something like this:

Percentage (SOC)	1 Cell	12V	24V	48V
100% Charging	3.65	14.6	29.2	58.4
100% Rest	3.40	13.6	27.2	54.4
90%	3.35	13.4	26.8	53.6
80%	3.32	13.3	26.6	53.1
70%	3.30	13.2	26.4	52.8
60%	3.27	13.1	26.1	52.3
50%	3.26	13.0	26.1	52.2
40%	3.25	13.0	26.0	52.0
30%	3.22	12.9	25.8	51.5
20%	3.20	12.8	25.6	51.2
10%	3.00	12.0	24.0	48.0
0%	2.50	10.0	20.0	40.0

So at 3.313 it should have been far closer to 70% than 9%. 16 x 3.313 is just over 53V.

Also, managed to find installation guides over at Pytes USA:

Pytes Energy Storage System-home battery storage-Pytes Battery

There Exist An Excellent Residential Battery Manufacturer Which Produces Home Energy Storage Systems And Home Battery Storage,Welcome To Buy Residential Battery.

www.pytesusa.com

and that includes a guide for Afore.

They actually state: DIP switches for Afore, Inverter set to Afore batteries and vMin and vMax of 56.0V both.

Now, my installer did set the DIP switches to Afore but set the Inverter to Pytes. Strange that Pytes say to leave it at Afore but I guess if the DIP switches do proper emulation then that makes sense.
That Pytes USA guide is from the end of October so very new. (Another new things is that Afore's App is now on the Play Store - looks a bit better but of course still no settings and still nothing there or on Afore's website which can at least read the settings.)

Anyway, after balancing the two batteries (charged twice then disconnected at 99%/100%, then reconnected today), I changed the Afore inverter settings to what Pytes USA recommend.

Battery is currently still at 41% overall, but looking at the volts it still seem wrong:

Battery	Volt	Curr	Tempr	Coulomb	mAH
#1	3305	-2677	12000	0.13	13717
#2	3307	-2552	12000	0.71	70713

The person on the MSE forum suggested that 10% being 3.3V is closer more what you'd expect from Lithium Ion not LiFePO4, although the same source as the previous table for Lithium-Ion gave me this:

Lithium-Ion Battery Voltage Chart
Charge Capacity (%)	1 Cell	12 Volt	24 Volt	48 Volt
100	3.40	13.60	27.20	54.40
90	3.35	13.40	26.80	53.60
80	3.32	13.30	26.60	53.10
70	3.30	13.20	26.40	52.80
60	3.27	13.10	26.10	52.30
50	3.26	13.00	26.00	52.20
40	3.25	13.00	26.00	52.00
30	3.22	12.90	25.80	52.50
20	3.20	12.80	25.60	51.20
10	3.00	12.00	24.00	48.00
0	2.50	10.00	20.00	40.00

But that does say that 3.3V for Lith-ion is about 70%. Baffled.

No idea what is responsible for this, but I would expect that the Inverter shouldn't know anything about this, so it surely must be Pytes' BMS?

Wonder if there is a firmware update for the Pytes? Never did get Pytes to reply to me - my most recent attempt was posting on Pytes NL's Facebook page but nothing.

Wonder if any of the other DIP switch settings would make any difference. Presumably with all off, the battery identifies as Pytes and the Afore inverter claims to have a setting for that.

Looked through DIY solar thread about the Pytes but didn't see anyone output the battery cell info.

As for the rest of MSE, well the consumer rights experts pointed out that after 6+ months it would now be for me to prove something is wrong, but before that the burden of proof was on the installer. Lucky that they and their friend the regulator managed to drag it all past 6 months then

HungryHippos · 12 Dec 2023 at 19:49

KompuKare said:
As for the rest of MSE, well the consumer rights experts pointed out that after 6+ months it would now be for me to prove something is wrong, but before that the burden of proof was on the installer. Lucky that they and their friend the regulator managed to drag it all past 6 months then

You should be OK if you have evidence that you were trying to get the installer to help solve the issue before 6 months was up surely?

KompuKare · 12 Dec 2023 at 20:31

HungryHippos said:
You should be OK if you have evidence that you were trying to get the installer to help solve the issue before 6 months was up surely?

Possibly, as I first noticed something was wrong well within 6 weeks never mind months and it probably would have been even sooner if the initial install wasn't messed up, plus last February the batteries stopped charging as it was too cold.

Meanwhile, watching the BMS and the logs... 34% SOC and bat#1 is already at
Volt Curr Tempr Base State Volt. State Curr. State Temp. State Coulomb
3261 -7304 12000 Dischg Normal Normal Normal 5% 5421 mAH
Yet for a LiFePO4, 3.261 is near 50%.
Bat #2 on the other hand:
Volt Curr Tempr Base State Volt. State Curr. State Temp. State Coulomb
3261 -6120 12000 Dischg Normal Normal Normal 64% 64164 mAH
Same voltage but there the BMS says 64% which is above what the table in my last post implies.

b0rn2sk8 · 14 Dec 2023 at 21:48

So I finally signed with an installer for my install after my false start with First4solar in 2022. It's a very different market to 2022 so I think it's fair to say if you find a couple of installers who are keen and wants the work, it makes it a lot easier to get a very competitive quote. While my preferred installer didn't give me the best quote initially, they were by far the most communicative and a friend recently used them and had an excellent experience.

Alongside far better pricing, the other key difference to when I was looking a year ago is lead times. I'm looking at a few weeks compared to 3-6 months just 12 months ago.

The set up will be:
23 435W JA all black panels
8kw Solis inverter
13.5kwh Giv Energy All in one w/ gateway
Bird protection

The cost is £16,400.

This is split over 9 east and 14 west arrays so while I will have 10kw of panels, I'll 'only' be producing ~7.5mwh/year. I've also got a conservatory which adds a bit of complexity/cost to the scaffolding. None of my neighbours have bird protection but I regularly see pigeons in the hedges around my house and they tried to nest in my gutter in 2022 so I think it would very much be a case of 'when' and not 'if' they decide to roost under the panels. The inverter is no frills but all the clever stuff happens in the battery so it doesn't really matter and in this set up it's very much a set and forget component.

I could technically fit 16 panels on my west aspect, it means using a second inverter and a slightly more complex install so the marginal cost of those two panels is quite high meaning the ROI isn't the best.

If you want a laugh, this is a legit quote I got in 2022:
20 400W Tier 1 panels (again east west)
5kw Solis inverter
9.6kwh Pylontech Batteries
Bird protection
£20,881

While a Solis/Pylon setup can be good value, it doesn't fit my needs because its basically dumb. Everything has to be done via the control panel on the inverter which basically incompatible with variable time of use tariffs like Octopus Intelligent Go and EV charging generally.

Journey · 14 Dec 2023 at 21:56

Not sure I'd want an ESS like that with AC coupling tbh. Why have you gone the Solis route with Giv over other options?

b0rn2sk8 · 14 Dec 2023 at 22:15

The solar string inverter is almost irrelevant when using an AC coupled battery, cheap, dumb and reliable is fine. Even if I wanted to match it all in brand wise, Giv energy don't do a a big enough single phase inverter for my panel setup and the inverters cost considerably more.

What's the issue with AC coupled? Sure you lose a little round trip efficiency but you can't argue with the capabilities of systems like the GIV AIO or Tesla Powerwall. Pricing isn't too bad either, particularly once you are in the realms of putting two batteries (say a 9.5 and 5.2) on a Giv Energy hybrid inverter. The power wall was surprisingly competitive as well, I guess they are clearing stock for the V3 due any day now.

Journey · 14 Dec 2023 at 22:47

b0rn2sk8 said:
The solar string inverter is almost irrelevant when using an AC coupled battery, cheap, dumb and reliable is fine. Even if I wanted to match it all in brand wise, Giv energy don't do a a big enough single phase inverter for my panel setup and the inverters cost considerably more.

What's the issue with AC coupled? Sure you lose a little round trip efficiency but you can't argue with the capabilities of systems like the GIV AIO or Tesla Powerwall. Pricing isn't too bad either, particularly once you are in the realms of putting two batteries (say a 9.5 and 5.2) on a Giv Energy hybrid inverter. The power wall was surprisingly competitive as well, I guess they are clearing stock for the V3 due any day now.

I think the thing that would annoy me is the limited output of the battery only at a sustained 6kW, vs a proper ESS setup with a DC coupled inverter to dumb batteries a la Victron. I guess it might not bother you too much, as you may not want to use your battery storage for electric based heating, or an electric shower etc. It's not like you are getting the system cheap either, the panels, inverter and Giv AIO/Gateway are only ~£8.3k+VAT, so 50% of you costs are mounting, bird protection and install, its no wonder they can fit you in so fast!

TBH was just curious, and it is always good to have other user thoughts, I got rid of my Giv system and went Victron, due to how limited the Giv system is and how reliant you are on there own servers etc. However I also arranged it all myself, so have a skewed value perspective, the important thing is you are happy and you have done your research.

b0rn2sk8 · 14 Dec 2023 at 23:30

Incidentally it was one of the few installers that gave me a price breakdown of everything, down to the sticker sheet so i know where all their margin is and it’s not on the components or the scaffolding, it’s all the labour/fit.

I ended up getting 5 like for like quotes in the end and most were a lot higher.

I’d say your value proposition is somewhat skewed, victron kit is not exactly for your average consumer, particularly when you are relying on the installer to design and project manage it for you. That’s ultimately what you pay for, you hand over a wad of cash and a few weeks later your system is installed without any further thought.

Journey · 14 Dec 2023 at 23:52

b0rn2sk8 said:
Incidentally it was one of the few installers that gave me a price breakdown of everything, down to the sticker sheet so i know where all their margin is and it’s not on the components or the scaffolding, it’s all the labour/fit.

Be interesting to see that, as design, fit, finish and warranty must be a massive chunk if there isn't much margin on the components as you say.

Ron-ski · 15 Dec 2023 at 06:47

Journey said:
I got rid of my Giv system and went Victron, due to how limited the Giv system is and how reliant you are on there own servers etc.

Smart move, Victron is so flexible. I can literally write code that runs on the Victron system, it can do almost anything, it controls my battery heating system, I use my phone to set schedules for discharging, saving sessions, free electric sessions, it also uploads to PV Output.

200sols · 15 Dec 2023 at 08:22

b0rn2sk8 said:
I’d say your value proposition is somewhat skewed, victron kit is not exactly for your average consumer, particularly when you are relying on the installer to design and project manage it for you. That’s ultimately what you pay for, you hand over a wad of cash and a few weeks later your system is installed without any further thought.

Well said.

Journey · 15 Dec 2023 at 09:06

200sols said:
Well said.

Well it's not as you can also pay an installer to do the same thing with Victron kit if you wanted, but the whole point is, if you want to, you can do more with it yourself and not be stuck with what comes out-of-the-box. Same wad of cash, different approach.