Solar panels and battery - any real world reccomendations?
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Soldato
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My hybrid does whole house EPS (the main house tails were diverted to go into the system so it could perform this function), and discharges at 5.5kwh. Its notionally a 5kwh. But will allow 200% overpanelling (10kwp) and 150% solar generation (7.5kw)
Its a solax, although apparently they do have a rep as being good on the inverter side.
I think very much unlike things like a NAS, the whole point of solar is generation and getting your investment back.
The more you spend the longer it needs to function for.
Its a solax, although apparently they do have a rep as being good on the inverter side.
I think very much unlike things like a NAS, the whole point of solar is generation and getting your investment back.
The more you spend the longer it needs to function for.
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@Mercenary Keyboard Warrior Did you resolve you're capacity issues? I remember they changed all the batteries in the end.
Soldato
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To be honest I stopped working on it pre xmas when it got cold.
I was plotting charge vs temps and when I had a decent chunk of data I planned to see if there was any correlation. Found that excel has it handily.
I need to go back and pull all the data since. I will check vs starting and ending temp, to my mind ending is the important one since if they are 20C at the end they should be close to the capacity (nominally Solax claim at 25C, although the normalised temp for this tech is 100% capacity at 23C)
It only works when there are 10-100% charge days so I have some days I need to exclude.
SOC is as we have discussed before basically useless.
They offered to exchange all again (would have been second full exchange) but then revised to only change two after so more detailed logging.
I did see a couple of days with capacity added of close to expectation, but it was only a couple.
It gave me some hope that they may be resolved.
With powerups assuming they continue I will test in the spring / summer as well.
Obviously last year I was not keen to spend a lot from grid on repeatedly testing from empty since it was costing me £3-4 an attempt.
If I could get to 10kwh consistently most months I would be "happy".
Annoying the battery heating is only for keeping them running, and not to keep them running at capacity if that makes sense.
Obviously mine are about 90% covered with insulation. I planned to add a little more insulation and potentially a little extra heating (one of those sealed long thin heaters used in schools etc).
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Normally I'd say yes, but there are some super aggressive prices on offer installers for 405-410w panels right now, heck even at retail you can get all black 410w for just over £50 each, where as the 435w's are £78-85 range. Overall it isn't a big cost increase at £700 (20 panels at £35 uplift), especially over 15-25 years, but I'd also look at where else that £700 could benefit the system, e.g. a better higher power inverter etc.
Hi,
Thanks for your reply!
They have said they can split the panels across 3 roofs but will need an extra investor but is it better to get a larger inverter?
Do you know who can provide 20 x 435w panels for the same price?
I do have a second quote but it's more expensive and has 430w panels with 2 inverters
As journey said, it may be that they have got a good deal on older panels as 405/410w panels are not the latest offering anymore. 435w is the standard and 450w panels are hitting the market now but the latter is more expensive.
Most inverters only have inputs for 2 strings. You can’t put panels which face a different directions onto the same string so if you have 3 roofs it’s normal to use 2 inverters.
You can get inverters with more than 2 inputs but there are wider considerations. They’ve probably gone with the most cost effective option.
When you say spread out over 3 roofs, what direction are they and how many can you fit in each?
You want to be maximising your most southerly facing roof with as many panels as possible in first instance.
A lot of your solar installation costs are fixed so the marginal cost of adding extra panels tends to be small and it’s usually most cost effective to just as as many panels to the house as will physically fit as they’ll be up there for 25 years. Going back and adding more later is prohibitively expensive.
For example, scaffolders tend to charge per side of the house and your fitters will be charging you labour by the day so the cost difference between fitting 10 and 12 panels on the roof span is basically just the raw material cost.
Most inverters only have inputs for 2 strings. You can’t put panels which face a different directions onto the same string so if you have 3 roofs it’s normal to use 2 inverters.
You can get inverters with more than 2 inputs but there are wider considerations. They’ve probably gone with the most cost effective option.
When you say spread out over 3 roofs, what direction are they and how many can you fit in each?
You want to be maximising your most southerly facing roof with as many panels as possible in first instance.
A lot of your solar installation costs are fixed so the marginal cost of adding extra panels tends to be small and it’s usually most cost effective to just as as many panels to the house as will physically fit as they’ll be up there for 25 years. Going back and adding more later is prohibitively expensive.
For example, scaffolders tend to charge per side of the house and your fitters will be charging you labour by the day so the cost difference between fitting 10 and 12 panels on the roof span is basically just the raw material cost.
But you can connect two or more identically paneled strings facing different directions in parallel using a combiner box, or even just two strings using MC4 Y connectors, then use 1 mppt input on the inverter. Obviously observing voltages/amps limitations and some other requirements if more than two strings.
Here is my recent quote with just the kit suggested by tamzzy:
I have had a few quotes, and as much as I like the Tesla (or similar) battery solution, I cannot see enough advantages for this as it significantly increases the ROI. I have a west-east-facing roof with a little shade from surrounding trees. One quote that I am interested in is 12x 435 Jinko Panels with 12 tigos, 2x 5.12 SunSync batteries, and a SunSync 5kw invertor. This includes relevant certification, scaffolding and bird barriers. I use around 4000kw a year. The estimate is £10500. My questions are around the SunSync solution – there are so many to consider? How do you feel about the cost of this system? Thank you for any feedback you might offer over this.
I have had a few quotes, and as much as I like the Tesla (or similar) battery solution, I cannot see enough advantages for this as it significantly increases the ROI. I have a west-east-facing roof with a little shade from surrounding trees. One quote that I am interested in is 12x 435 Jinko Panels with 12 tigos, 2x 5.12 SunSync batteries, and a SunSync 5kw invertor. This includes relevant certification, scaffolding and bird barriers. I use around 4000kw a year. The estimate is £10500. My questions are around the SunSync solution – there are so many to consider? How do you feel about the cost of this system? Thank you for any feedback you might offer over this.
Why have they quoted for optimisers if you don’t have issues with shading?
What ever you do with on batteries, the key things to look out for is:
Max charge/discharge rates - this may we’ll be lower than the inverter power and varies by battery model, even from the same manufacturer.
Depth of discharge - this is how much of the battery is usable. Some market their battery as the usable capacity or 100% DoD, others market the gross capacity which and an 80% depth of discharge. As above, it’s not necessarily even consistent from the same brand, check each quote carefully.
What ever you do with on batteries, the key things to look out for is:
Max charge/discharge rates - this may we’ll be lower than the inverter power and varies by battery model, even from the same manufacturer.
Depth of discharge - this is how much of the battery is usable. Some market their battery as the usable capacity or 100% DoD, others market the gross capacity which and an 80% depth of discharge. As above, it’s not necessarily even consistent from the same brand, check each quote carefully.
hey mate i'm assuming you saw the bill i posted for my PV system
i would've thought that your quote is reasonable (maybe £500-£1000 dearer than february pricing...but apparently material costs have increased slightly since feb, so would explain the difference)
assuming your quote is for the sunsynk ECCO hybrid inverter, the 5kw version will provide 5kw max charge and discharge rates regardless of the source (PV or battery)
assuming your quote for the battery is the sunsynk L5.1 - this is a 90% DOD battery, so the usable battery is 4.6kwh each...so 9.2kwh for two batteries
for the L5.1 batteries...each battery can only supply 2.5kw peak discharge rates, so two batteries will be a good pairing for your 5kw inverter especially if you have very spiky loads
regarding your PV panels, i am not sure if a 6:6 E-W split will max out the 5kw charge rate for the inverter - happy for someone more knowledgeable to correct
Hi thanks for this.
I now have a new quote for 20 x Jingko Toger Neo panels, with 20 TIGOs, a givenergy 5kw inverter and a givenergy 9.5 gen 2 battery for £11.2k.
I have the option of changing the battery to Fox ess 8.7kw for around £10.8K.
The system would be 8.6kw so wondering whether the inverter is enough at 5kw?
Can you guys advise on whether I should go for one of these batteries and inverter or go for something else?
Your help is much appreciated.
Whats the expected solar generation?
Hi its a 8.7kwh system.
Adding up the generation by month comes to 7018kwh per year according to their quote.
Daily generation ranges from 5.1kwh in December to over 30kwh from May to July.
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Thank you for this helpful reply. Is it more sensible then to look at the giv-energy all in one as a solution with its improved peak power? More expensive for sure, but not as rich as a PW.
@kevinpat it depends on your usage.
For example if you're going to cryptomine, boil your kettle, use the vacuum cleaner, dishwasher and tumble dryer all at the same time then no, not even a 6kw peak inverter would cope with that level of power requirements.
However if you're "just" an average user than a 5kw inverter is more than enough.
For example if you're going to cryptomine, boil your kettle, use the vacuum cleaner, dishwasher and tumble dryer all at the same time then no, not even a 6kw peak inverter would cope with that level of power requirements.
However if you're "just" an average user than a 5kw inverter is more than enough.
Associate
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- 28 Dec 2023
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- Midlands
Hello all,
Hopefully I'm doing this correctly.
Firstly I have been lurking here since the start of this thread and wanted to thank you all for your wisdom and insight.
This is my first posting so be patient.
I am about to pull the trigger on this.
8 JA solar 435 w black panels.
Givenergy 3.6 KW hybrid inverter
Givenergy 9.5 battery.
Bird protection.
No scaffolding needed as it's on double garage. (Faces south)
I'm on intelligent octopus also.
I can't get any more panels on unfortunately.
I was thinking to have the 5kw inverter and the g99 as the inverter is the same price.
£7,700
Thoughts please.
Hopefully I'm doing this correctly.
Firstly I have been lurking here since the start of this thread and wanted to thank you all for your wisdom and insight.
This is my first posting so be patient.
I am about to pull the trigger on this.
8 JA solar 435 w black panels.
Givenergy 3.6 KW hybrid inverter
Givenergy 9.5 battery.
Bird protection.
No scaffolding needed as it's on double garage. (Faces south)
I'm on intelligent octopus also.
I can't get any more panels on unfortunately.
I was thinking to have the 5kw inverter and the g99 as the inverter is the same price.
£7,700
Thoughts please.
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