Solar panels and battery - any real world reccomendations?

JDR82 said:
However they also highlighted that will take me to 6.4kW system and the inverter is 5.6kW so will be clipping in the summer.
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Yeah as @ronski said as well.

I wouldn't worry about that at all, once you factor in heat loss in the summer you'll probably find you don't even hit 5.6kw anyway.

The added panels are always well worth it for the overall generation.

The other thing is unless you are using it, which means running a lot of high load electrical items during, what, maybe 3 hours during the middle of the day, in the middle of the summer, what is it you are really loosing?
 
BUDFORCE said:
Yeah as @ronski said as well.

I wouldn't worry about that at all, once you factor in heat loss in the summer you'll probably find you don't even hit 5.6kw anyway.

The added panels are always well worth it for the overall generation.

The other thing is unless you are using it, which means running a lot of high load electrical items during, what, maybe 3 hours during the middle of the day, in the middle of the summer, what is it you are really loosing?
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Agree, I wouldn't worry. Can you over load the inverter? I can feed mine 155% of it's capacity.
 
b0rn2sk8 said:
Interesting development, I had one final installer come to quote today and he suggested that they fit a Tesla power wall for the same price as the giv energy all in one now.

I had previously written it off as too expensive but I’m intrigued as to what price they come back with.
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Bear in mind that the Powerwall does not let you control discharge of the battery, so force exporting when export prices are high is not possible (and with the changes to saving sessions this year, force exporting could be quite a nice earner) I believe the only options for force exporting with it were signing up to a tariff that controlled the charge and discharge for you.
 
Overloading the inverter or over panelling is very much a thing.
Panels are now cheap so adding in more seems a no brainer within reason.

I am seriously looking at over panelling right now. I am looking to combine my two west strings into one inverter string (7 panels serial, x2 strings in parallel) and adding a south facing array on my south wall.

I have been through a Solax designer and get two warnings with my plan.
String 1, the one I would combine my west strings into generates 2 warnings. 1st, "Yield loss. The peak PV power of this MPPT is larger than max DC power of this MPPT. The input power will be limited"
2nd warning "Yield loss. The maximum array current is greater than the DC current permitted through the inverter. As a result energy losses will occur"
1st is because peak power (Wp) is 5.68kw and each string is limited to 5kw. Other than odd spikes in summer the panels seem to cap out around 4.4kw anyway.
2nd is because the A potential of the 14 panels in 2x7 panel strings is 22.12A and the max is 16A.
The MPPT should handle both of those by clipping the current.

My inverter allows 100% over panelling, so 5kw inverter allows 10Wp. And allows PV input of 50% over, so 7.5kw.

My suggested system would be just over 8kw, but with West facing and South facing its unlikely to manage to hit the 7.5kw

Their site designed gives a green tick in regards the system design. A yellow warning on the 1st warning mentions "if this combination was consciously selected and from experience delivers good yield no change necessary"
The second gives an Amber as its clearly more impact, suggested is to "reduce strings, change panels or select a larger inverter." I am happy to allow clipping since if it sits at 249v (what it says should happen) and 16A thats basically 4kw. And its pretty rare that my west strings combined sit above 4kw anyway.
Super sunny days, sure, they regularly sit at 4.3-4.4kw, but I am happy to drop 300-400w of generation in order to gain 2.5kw south facing array.
 
john_smith said:
Yes, it looks closer now. Wonder if we'll see it in the UK at the same time as the USA.

Where you can't pair it to a PW2 I dont think the PW2 will be disappearting any tme soon. I hope....as i'd like to add another at some point.
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Is there a great deal of difference between the PW 2 and 3?
 
Mercenary Keyboard Warrior said:
Overloading the inverter or over panelling is very much a thing.
Panels are now cheap so adding in more seems a no brainer within reason.

I am seriously looking at over panelling right now. I am looking to combine my two west strings into one inverter string (7 panels serial, x2 strings in parallel) and adding a south facing array on my south wall.

I have been through a Solax designer and get two warnings with my plan.
String 1, the one I would combine my west strings into generates 2 warnings. 1st, "Yield loss. The peak PV power of this MPPT is larger than max DC power of this MPPT. The input power will be limited"
2nd warning "Yield loss. The maximum array current is greater than the DC current permitted through the inverter. As a result energy losses will occur"
1st is because peak power (Wp) is 5.68kw and each string is limited to 5kw. Other than odd spikes in summer the panels seem to cap out around 4.4kw anyway.
2nd is because the A potential of the 14 panels in 2x7 panel strings is 22.12A and the max is 16A.
The MPPT should handle both of those by clipping the current.

My inverter allows 100% over panelling, so 5kw inverter allows 10Wp. And allows PV input of 50% over, so 7.5kw.

My suggested system would be just over 8kw, but with West facing and South facing its unlikely to manage to hit the 7.5kw

Their site designed gives a green tick in regards the system design. A yellow warning on the 1st warning mentions "if this combination was consciously selected and from experience delivers good yield no change necessary"
The second gives an Amber as its clearly more impact, suggested is to "reduce strings, change panels or select a larger inverter." I am happy to allow clipping since if it sits at 249v (what it says should happen) and 16A thats basically 4kw. And its pretty rare that my west strings combined sit above 4kw anyway.
Super sunny days, sure, they regularly sit at 4.3-4.4kw, but I am happy to drop 300-400w of generation in order to gain 2.5kw south facing array.
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I'm tempted to increase mine from 37 panels as I could in theory have 30kW panels - only downsides are finding room to put them all and probably more importantly I'm only single phase + but I suppose the Inverters would limit that anyway.
 
Mercenary Keyboard Warrior said:
Overloading the inverter or over panelling is very much a thing.
Panels are now cheap so adding in more seems a no brainer within reason.

I am seriously looking at over panelling right now. I am looking to combine my two west strings into one inverter string (7 panels serial, x2 strings in parallel) and adding a south facing array on my south wall.
<snip>
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Yes very similar my predicament but I am happy to wait for the cost, particularly if panels keep getting cheaper, batteries improve and could time it when the inverter is older to get most out of current one. It was the long term plan anyway as there's loads of space for South facing panels, I wasn't clued up on the string arrangement etc. but can now design as I have plenty of time to mull all that over.
 
Just before I go back to the installer.

I noticed on and off today, the solar generating say 2kw, house using 500w, and the rest going out to the grid, seems intermittent but for periods of maybe 15-20 minutes, on and off.

I also noticed on several occasions over the last week and a half, the battery sitting there at idle, whilst the solar is feeding the grid, and for well over an hour. On the app, the home data seems to be working (all be it showing it going out the grid) the cloud data shows "error". When it is like that, if I disconnect the AC inverter at the isolator, wait 10 seconds or whatever, put it back on, within a minute or two it'll start charging the battery as expected.

Its a givenergy AC coupled inverter and battery.

Any ideas? It doesn't seem right to me.
 
BUDFORCE said:
Just before I go back to the installer.

I noticed on and off today, the solar generating say 2kw, house using 500w, and the rest going out to the grid, seems intermittent but for periods of maybe 15-20 minutes, on and off.

I also noticed on several occasions over the last week and a half, the battery sitting there at idle, whilst the solar is feeding the grid, and for well over an hour. On the app, the home data seems to be working (all be it showing it going out the grid) the cloud data shows "error". When it is like that, if I disconnect the AC inverter at the isolator, wait 10 seconds or whatever, put it back on, within a minute or two it'll start charging the battery as expected.

Its a givenergy AC coupled inverter and battery.

Any ideas? It doesn't seem right to me.
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That doesn't sound right to me, I have givenergy AC coupled battery as well and reaction times are usually within a few seconds. You haven't set a max charge limit or anything for the battery?
 
200sols said:
That doesn't sound right to me, I have givenergy AC coupled battery as well and reaction times are usually within a few seconds. You haven't set a max charge limit or anything for the battery?
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No definitely not.

2 of the occasions the battery was at 5% or something, sitting there idle whilst 1.5kw or so is going out to the grid......
 
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