Solar panels and battery - any real world reccomendations?

Mercenary Keyboard Warrior said:
Someone way more knowledgeable may come to help, but my understanding is,
You need to check the MPPT limit per string. You would add the NE panels as one string and the SW as the other.
As such you would need an inverter that can handle around 4kw per string.

The other way is simply another inverter sitting in parallel with what you have now.
The attractiveness of that is that should one inverter go down (the most likely point of failure) then you at least have the other array still operating.

You could get a new inverter thats capable of running both and still leave the old one as is. Then if the old one fails you can switch it over later.

FWIW why did you originally have 16 on the NE when 10 on the SW would likely have been as good if not better at generation!?
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It's a new build so unfortunately I had no say in the matter. I'm looking at the new Viridian 405w panels and I think i can fit 9/10 of these on the SW roof.

I imagine the cost of 270w panels is why they were chosen or the site was specified when thats all that was available and to get to 4kw needed they had to put 16 on and the only space was on the NE roof.
 
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NeilMick said:
It's a new build so unfortunately I had no say in the matter. I'm looking at the new Viridian 405w panels and I think i can fit 9/10 of these on the SW roof.

I imagine the cost of 270w panels is why they were chosen or the site was specified when thats all that was available and to get to 4kw needed they had to put 16 on and the only space was on the NE roof.
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LuxPower inverters will take 8kw per string iirc, beware that voltage also matters.
 
Update:

I've had an engineer visit from the battery manufacturer!

The outcome of his assessment is that the original installer had not commissioned the system correctly. Therefore the battery was never going to work as intended.

The battery manufacturer engineer sorted it out this morning and the system is fully operational almost 4 weeks since it was installed!
 
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Hi guys, just posting here if anyone knows a bit more behind why, I think..... I sort of get it.

Have a current solar system, 4.5kw on a 5kw non-hybrid inverter, no optimisers currently.

No battery either, but otherwise working great.

Got a quote for a battery and 3 more panels on the garage roof, which will really give a boost because the potential new 3 are south/west facing, whilst the rest of our panels are south/east facing, so the potential new ones will catch a lot of the later afternoon sun, basically that garage roof is always in full sun in the afternoon/evening (if its not cloudy, obviously!), I am confident those three panels will make a huge difference even if only around 1kw in total.

Anyway, they are going to put in an AC coupled battery, which I am fine with, but when it comes to the three panels he said they would fit optimisers on them, to keep the seperate from our other panels.

The inverter we have has 2 input strings, with the current 12 panels only using 1 string. I am guessing, the reason, and sole reason for the optimisers is to boost the voltage of the three panels to make sure they have enough to meet the startup minimum for the remaining unsused string?

I know I could ask him, but trying to get an idea myself.
 
BUDFORCE said:
Hi guys, just posting here if anyone knows a bit more behind why, I think..... I sort of get it.

Have a current solar system, 4.5kw on a 5kw non-hybrid inverter, no optimisers currently.

No battery either, but otherwise working great.

Got a quote for a battery and 3 more panels on the garage roof, which will really give a boost because the potential new 3 are south/west facing, whilst the rest of our panels are south/east facing, so the potential new ones will catch a lot of the later afternoon sun, basically that garage roof is always in full sun in the afternoon/evening (if its not cloudy, obviously!), I am confident those three panels will make a huge difference even if only around 1kw in total.

Anyway, they are going to put in an AC coupled battery, which I am fine with, but when it comes to the three panels he said they would fit optimisers on them, to keep the seperate from our other panels.

The inverter we have has 2 input strings, with the current 12 panels only using 1 string. I am guessing, the reason, and sole reason for the optimisers is to boost the voltage of the three panels to make sure they have enough to meet the startup minimum for the remaining unsused string?

I know I could ask him, but trying to get an idea myself.
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your inverter may need 100v start up for the 2nd string and you may not get that with 3 panels. im about to fit 4 new ones in a seperate string with 30v each, so i can meet the 100v start up of the 2nd MPPT in the inverter.
 
BUDFORCE said:
Hi guys, just posting here if anyone knows a bit more behind why, I think..... I sort of get it.

Have a current solar system, 4.5kw on a 5kw non-hybrid inverter, no optimisers currently.

No battery either, but otherwise working great.

Got a quote for a battery and 3 more panels on the garage roof, which will really give a boost because the potential new 3 are south/west facing, whilst the rest of our panels are south/east facing, so the potential new ones will catch a lot of the later afternoon sun, basically that garage roof is always in full sun in the afternoon/evening (if its not cloudy, obviously!), I am confident those three panels will make a huge difference even if only around 1kw in total.

Anyway, they are going to put in an AC coupled battery, which I am fine with, but when it comes to the three panels he said they would fit optimisers on them, to keep the seperate from our other panels.

The inverter we have has 2 input strings, with the current 12 panels only using 1 string. I am guessing, the reason, and sole reason for the optimisers is to boost the voltage of the three panels to make sure they have enough to meet the startup minimum for the remaining unsused string?

I know I could ask him, but trying to get an idea myself.
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Sounds very likely its exactly that to get the voltage as opposed to keeping them separate as different string.

Was it you that replaced your inverter a while back? Bad timing if so.
There is a disadvantage from AC coupled. They are of course DC really.

So if you have excess solar and an AC coupled the panels generate DC, the inverter converts to AC, the AC battery inverter detects the excess AC current, converts it back to DC and into the batteries.
If you have a hybrid they take the excess DC and send it directly to the batteries as DC.
Its no massive biggie but you add an extra couple of conversions in effect with AC coupled. (For your own excess generation to battery only)
 
@Welshman
@Mercenary Keyboard Warrior

Ok thanks guys.

I did look into it a year ago or so and reckon 3 panels would just about produce enough startup voltage, as the inveter I have seems to have a reasonably low threshold, but I guess by adding the optimisers it acts as a backup/insurance, so that makes sense why they want to add them.

No it wasn't me who replaced the inverter recently, and yes I know AC coupled batteries loose a bit in effeciency because of the coverting, but can stick with the inverter I already have, I do regret not getting a battery with teh original install in hind sight, but nevermind.

I've given the installer the green light, they did our current setup which has been fine for a bit over a year so hopefully should all go smoothly. Should be a good overall setup when done as well, much more efficient than it is currently.
 
BUDFORCE said:
I've given the installer the green light, they did our current setup which has been fine for a bit over a year so hopefully should all go smoothly. Should be a good overall setup when done as well, much more efficient than it is currently.
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How come you've changed your mind so quickly? Didn't the installer say it would be a bad idea for your setup, and they wouldn't recommend it for you, is the price considerably less than when they originally quoted you?
 
fullspizz said:
Finally pushed the button on the below, longer to choose than expected due to my back boiler being condemned and had to be replaced.
Solar Panels
LONGi
4.5 kW Total Solar Power
9 x 500 Watt Panels (LR5-66HIH-500M) (4 on east and 5 on west)
3,319 kWh per year

Inverter
Growatt New Energy Technology Co., Ltd.
3.6 kW Total Inverter Rating
1 x SPH3600

Battery
Growatt New Energy Technology Co., Ltd.
6.5 kWh Total Battery Storage
1 x Growatt GBLI6531

Bird Deterrent Mesh

Bird Deterrent 30 Meter Roll PVC Coated Solar Mesh
1 x BIRD-MESH-BLK


EV Charger


1 x ZAPPI-2H07UW : Zappi - 7kW (WiFi) (tethered)

Due to an east/west facing roof, 2 sides of scaffolding.
£8949, survey has been completed and installation booked for 16th October.
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That seems to be a really good price to me.
Where in the country are you and who is the installer?
 
Our install should be going ahead next Thursday / Friday, the biggest delay was getting the HomeEnergy Scotland grant, every reply just seemed to take forever.

Done now though so looking forward to finally getting it up and running in ti for all that Winter sun….

Any main things I need to be organising once the install is done, I am currently with ScottishPower, haven’t even looked at new tariffs / providers yet for the best deal.
 
JDR82 said:
Our install should be going ahead next Thursday / Friday, the biggest delay was getting the HomeEnergy Scotland grant, every reply just seemed to take forever.

Done now though so looking forward to finally getting it up and running in ti for all that Winter sun….

Any main things I need to be organising once the install is done, I am currently with ScottishPower, haven’t even looked at new tariffs / providers yet for the best deal.
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Got an EV/hybrid?
Most of us move to Octopus

Plenty of comments about it on here.

If you dont know anyone amongst friends and family, £50 can be had on switching, from a referal from loads of us on here.
 
Bit of help here again as I'm getting conflicting info from Octopus. As my battery and panels are all working. I want a good Octopus tariff. They advised me to get Intelligent Octopus. But when I looked it only shows for EV's. So that rules me out. The other Tariff they suggested was Flux. However, the cheap charge rate for the battery is only between 02.00 - 05.00.

The fitter suggested Agile in the winter and Flux in the summer. Again different information

I'm open to suggestions in plain English that doesn't get my brain overloading :)
 
How does this quote sound ?

15 x 400w Longi Hi-Mo 5M panels 11 on house, 4 on garage
Sunsynk 5kw inverter
Tigo Gateway
4 x Tigo Optimisers

£10,210

the quote includes trenching for the cable from the garage to the house @ £500/m, but there is a possibility of avoiding this by clipping the garage cable to a wall instead.

They also quoted me for 11 panels only with a 3.6kw inverter and that was £7350
 
MassiveJim said:
How does this quote sound ?

15 x 400w Longi Hi-Mo 5M panels 11 on house, 4 on garage
Sunsynk 5kw inverter
Tigo Gateway
4 x Tigo Optimisers

£10,210

the quote includes trenching for the cable from the garage to the house @ £500/m, but there is a possibility of avoiding this by clipping the garage cable to a wall instead.

They also quoted me for 11 panels only with a 3.6kw inverter and that was £7350
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£500 per meter to dig a trench? I'll come and do it for £250
 
MassiveJim said:
How does this quote sound ?

15 x 400w Longi Hi-Mo 5M panels 11 on house, 4 on garage
Sunsynk 5kw inverter
Tigo Gateway
4 x Tigo Optimisers

£10,210

the quote includes trenching for the cable from the garage to the house @ £500/m, but there is a possibility of avoiding this by clipping the garage cable to a wall instead.

They also quoted me for 11 panels only with a 3.6kw inverter and that was £7350
Click to expand...

I'm normally a go large kinda guy, but it doesn't look like the 4 panels would be good value for money.
IMO spend the £3k on batteries and you will probably see more benefit from that than the 4 extra panels.
 
NeilMick said:
£500 per meter to dig a trench? I'll come and do it for £250
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Bargain!! are you free next Tuesday ? :p
It sounds like a bit of a con, but the sales guy said they have to dig the trench themselves, he did explain the reason was in the past customers saying that there was a trench/ducting in place then the team arriving to the job and that not being the case.

The team that trench are totally seperate to the team that do the solar so I can kind of understand it.
No way would I pay it though, I would have to come to some sort of agreement, either they clip the cable to the wall or I put ducting in for them.



Mercenary Keyboard Warrior said:
I'm normally a go large kinda guy, but it doesn't look like the 4 panels would be good value for money.
IMO spend the £3k on batteries and you will probably see more benefit from that than the 4 extra panels.
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I also have a quote for 11 panels and a 5kw battery and that was the same as 15 panels without a battery


really annoying that the front of the house is south facing, because the roof at the back of the property is the same the whole way across, no dormers or gables etc, I reckon we could fit 30 panels on it.
 
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