Solar Panel Quote 3.5kw

Oneday77

Sorry yet another query on a PV quote, I haven't been here in a while.


I've had a quote today of £5,500, to fit a 3.5kW system.
It would be using: -
14 x SolarWorld sw250 panels
ABB PVI-3.0-TL_OUTD Invertor
iBoost
Schletter fixings and other components.
Price is all inclusive.


House sits 55degrees from South, towards the west, located 6 miles west of Aberdeen. Roof is at a 35degrees pitch.
Due to 2 Velux in the roof, we can't fit 16 panels. There is a small area on an extension roof we could fit 2 panels but would get some shading. 14 panels quoted have no shading and 2 string invertors.


Is my quote fair? Should we look at the 2 additional panels and go for micro invertors, though it was hinted this may cost another £1k.
We have only 1 quote so far but will get more.

warrenb

Why not go with 285w panels and get a 4kw system.

Oneday77

warrenb wrote: »

Why not go with 285w panels and get a 4kw system.

I need to go back to them to ask that. To be honest I was naive and didn't realise higher capacity one existed until I remembered to check in here
Though would I be better with String invertors and 14 panels or 16 panels and micro invertors? So many options :rotfl:

tunnel

Ask the installer to quote for 14 panels like warren says, price is a little minty for a 3.5kWp system but for a 4kWp it's not far off the mark.
Don't get fobbed off that the panels cost more money too. Try to aim for closer to £5k(or less). If the installer won't play ball....get some more quotes.

Oneday77

tunnel wrote: »

Ask the installer to quote for 14 panels like warren says, price is a little minty for a 3.5kWp system but for a 4kWp it's not far off the mark.
Don't get fobbed off that the panels cost more money too. Try to aim for closer to £5k(or less). If the installer won't play ball....get some more quotes.

I've just had a revised quote, that makes my last one wrong but even more expensive. The £5.5k apparently didn't include an iBoost.

Latest cost is £7,400.
That's for
16x Solarworld Panels
iBoost @ £400
Upgrading to enphase M215 micro inverters.

Going by previous comments I suspect this is far too high. For clarity, when people get a 4kW system, do they use string or micro inverters? Do micro's make a difference? Do they cost a lot more?
I've not asked about higher yield panels yet and have contacted some other local installers for quotes.

tunnel

Oneday77 wrote: »

For clarity, when people get a 4kW system, do they use string or micro inverters? Do micro's make a difference? Do they cost a lot more?
I've not asked about higher yield panels yet and have contacted some other local installers for quotes.

The only time to consider micros or solaredge is when you have ANY sort of shading(do you?) as these are primarily used for shade management. Most people with a single aspect roof and no shading would therefore use a string inverter, a duel aspect roof is fine with a dual MPPT(2 string inverter) although I wouldn't consider it a good idea with 2 panels as the start up voltage would be insufficient
Best if you look at higher wattage panels on a single string inverter
Again going back to shading....do you have any on the large roof?

Oneday77

tunnel wrote: »

The only time to consider micros or solaredge is when you have ANY sort of shading(do you?) as these are primarily used for shade management. Most people with a single aspect roof and no shading would therefore use a string inverter, a duel aspect roof is fine with a dual MPPT(2 string inverter) although I wouldn't consider it a good idea with 2 panels as the start up voltage would be insufficient
Best if you look at higher wattage panels on a single string inverter
Again going back to shading....do you have any on the large roof?

Sorry for the delay in replying. We have a 2 week and 3 yearold in the house and to say we are tired is an understatement

Until today I'd have said no to any shading. However we have a tall birch tree in one corner of the Garden. Today at about 5-6pm I noticed some shade about half a panel length up the roof. So yes I do.
Winter when the sun is lower, I doubt it will even still be up by that time so no biggie. Summer wise it's higher in the sky.
I could get the tree pruned but that could be an ongoing additional cost. However as I expect it to only be some months and even then maybe early/late evening would it even be worth the hassle.
The
I've had another quite though and it's healthier, though I forgot to ask about an iBoost. It's 4kW @ £5400 with 14x285W panels. It's been done blind so unless I've misquoted the stats, it should stand. Only problem is finding reviews on the Eging panels and Sunny Boy inverter.

Martyn1981

Hi. If the shading is only for a short period as you describe, then it might be ok to ignore it. You seem to suggest that when the sun is higher, it won't happen, and now the sun is lower, it's only happening at the very end of the generation day. If that's correct, then keep an eye on it this week see what time the shade starts to creep up the roof, and have a thunk.

The Sunny Boy range of inverters are made by SMA. They are a German company, and probably the most famous of all the makes. They are expensive, but very good, with excellent shade management software to cope with hard shade, such as chimneys, rooves etc. Assuming the quote is for a TL model (3600TL, 4000TL etc) then no probs.

Mart.

Oneday77

Martyn1981 wrote: »

Hi. If the shading is only for a short period as you describe, then it might be ok to ignore it. You seem to suggest that when the sun is higher, it won't happen, and now the sun is lower, it's only happening at the very end of the generation day. If that's correct, then keep an eye on it this week see what time the shade starts to creep up the roof, and have a thunk.

The Sunny Boy range of inverters are made by SMA. They are a German company, and probably the most famous of all the makes. They are expensive, but very good, with excellent shade management software to cope with hard shade, such as chimneys, rooves etc. Assuming the quote is for a TL model (3600TL, 4000TL etc) then no probs.

Mart.

Thanks for the early reply. It is a 3600TL inverter so that has put my mind to rest from that perspective.
Does the lack of reviews on Eging panels mean anything, are they OK? If it was consumer electronics I wouldn't have to ask a single question

I think the shade will be ok to ignore. At worst I get the tree a small operation, 30' up.
I'd just need to see if they string the inverters horizontally or vertically for the banks of Panels. I suppose it probably won't mater either way. Vertically may be better as if the shade was to reach the furthest away bank of panels, the sun is probably in it's dying minutes anyway. The worst would probably be crossing both banks at once and even then at the very end of the day.

Thanks for everyone's help and advice so far. The mud is slowly getting clearer.

Martyn1981

Hi. If your roof was SE, I'd say ignore the shade, but SW and from 5pm ....... it's almost ignorable (is that a word?) as we've reached September, but I think you're right to double check, and consider the string layouts to isolate the shading onto a single string. Might as well make the most of Septembers early evening sunshine.

Panels - sorry can't help. It's the most obvious question, that everyone asks, including myself when I was looking into PV, but there are hundreds of manufacturers, each with several models, and each model can have quite a few power output options. We'll know what we should have installed in 10yrs or so, or that it makes no difference, but till then ..... not what you want to hear, but ..... I dunno ..... sorry.

Mart.

Oneday77

Martyn1981 wrote: »

Hi. If your roof was SE, I'd say ignore the shade, but SW and from 5pm ....... it's almost ignorable (is that a word?) as we've reached September, but I think you're right to double check, and consider the string layouts to isolate the shading onto a single string. Might as well make the most of Septembers early evening sunshine.

Panels - sorry can't help. It's the most obvious question, that everyone asks, including myself when I was looking into PV, but there are hundreds of manufacturers, each with several models, and each model can have quite a few power output options. We'll know what we should have installed in 10yrs or so, or that it makes no difference, but till then ..... not what you want to hear, but ..... I dunno ..... sorry.

Mart.

Don't worry about the panels. It's an absolute mine field. I have had a couple more quotes today and my head is spinning. Ignoring differences of £50
I've 2 x14 285W quotes one JA Solar and the other Seraphim with Solis MPPT inverter 3600 About £5,700 inc iboost.

Also Same panels but with Solar Edge 3680W inverter and Solar Edge optimiser. About the £6,200 mark again inc iBoost or similar.

So pricing seems kind of standard up here, I wonder how keen they would be to hammer down the prices. The JA Solar Percium seems to jump out at me due to it's efficiency but that could be me blinded by science.

Do you ever get the feeling you shouldn't have started looking?