Finding PV suppliers with skill, availability and stock? (... AND not outrageous prices?)

[JohnMo]

Real life black panels (310W), GSE integrated with slates.

[puntloos]

3 hours ago, JohnMo said:

No not saying that - but you have to careful you are being ripped off.  I have solar (7kW) already and await a battery (13.6kWh) being installed. So I am all for Solar at the right cost.

 

 

So what am I missing price-wise, did I only find the wrong teams? Of course, the easyPV route certainly is cheaper per kwh but you (seemed to) call all of them a rip off

 

 

1 hour ago, joth said:

Last I looked at solar tiles (also GB sol) they cost 2x as much per m2 yet yield was 50% less per m2, so for a fixed roof size they give 1/4 of the kW/£ and half as much actual generation per year vs conventional panel. That alone is a none starter in my book.

 

I guess the challenge is that your claim seems to be true for DIY systems (easyPV for example) but the cost the installers I ran across are charging basically overrides that claim in end cost. This, compared to a 'at cost' price I'm estimating for the solar tiles, most videos I see online look like even I could do it (err.. not safely.. 50 degree roof is scary.., but you get the point) so indeed a standard roofer could do it.

 

1 hour ago, joth said:

Having used gb sol infinity I very much doubt the tiles are ideal for DIY install either, but a quick phone call to them would answer that 

Because they certainly will be honest about how hard their amazing product is in reality?

But yea, I'll give them a call and see about infinity too. 

 

1 hour ago, joth said:

I think there's very few situations they aesthetic is really justified for the inefficiency.

I agree, I guess all things being equal it starts to nudge things, and as you can see the tile price/kwh is actually cheaper than the two main installers... 

 

1 hour ago, joth said:

From what I know there wouldn't be many places your roof will be very visible from. The example photos above of GSE are misleadingly ugly as it's at a very close camera angle that in practice no one will ever be viewing a 3rd story roof from

True.

[JohnMo]

30 minutes ago, puntloos said:

So what am I missing price-wise, did I only find the wrong teams? Of course, the easyPV route certainly is cheaper per kwh but you (seemed to) call all of them a rip off

Should be cheaper per kW for the solar panel and kWh for the battery.

 

Basically your paying double what I did for your cheapest quoted.  My 2 systems (two inverters, multiple isolation switches etc) fully installed, including paying VAT were on average £670 per kW. A big array should have a good economy of scale, so costs per kW reduced.

[JohnMo]

Just had a quick look, a 370W panel from City Plumbing is £72 plus vat. So 26 panels is about £2k, do the mounting system cost £14k?

[puntloos]

21 minutes ago, JohnMo said:

Just had a quick look, a 370W panel from City Plumbing is £72 plus vat. So 26 panels is about £2k, do the mounting system cost £14k?

OK that's fair then. I think what's happening is that if someone is confident they know what to get (I guess that's also "experience", which is not unreasonable to have a cost), they can just buy off indeed cityplumbing or tradesparky, and then just pop it on the roof. The quotes I got were all in the same ballpark so certainly something is up. It might have to do with my location (hertfordshire, that's where all the posh people live, no?) but also I guess the "cowboy" element is the challenge, people just asking random prices and hey it seems to work.

 

Even easy-pv - which seems to be somewhat "cheaper" because you DIY is asking 140inc for the 370GBP Longi panel that's indeed 72 inc vat, but with a bit of luck I can push EasyPV site into giving me a selection for Longi 370 and go from there.

 

of course one "difficult" part is to install something *in-roof* rather than on-roof. Anyone here have DIY experience with in-roof/GSE? Easy? Hard?

 

 

Edited August 26, 2023 by puntloos

[puntloos]

OK. So. I've worked out the best PV Panel in the UK, in value for money sense.

 

Uh, it's @JohnMo's Longi 370WP - ha but my time was not fully wasted because instead I'm probably going for JA Solar JAM54s30 because it's the same basic size but much more power, or the JAM72S30-545 which is almost same price/sqm but much larger physically. Will have to check if it could fit a similar amount of panels. 

 

Here's all my research:

Shop	Brand	Type	SizeY	SizeX	Watt	Price ex	m2	GBP/kWh	W/sqm	PanelEst	TotalW	TotalCost	TotalW/C
tradesparky	JA	JAM54S30-410	1722	1134	410	80.76	1.95	197	801	21	8610	1695.96	5.076770679
easypv	Euren	Zebra 340	1684	1002	340	121	1.69	356	692	26	8840	3146	2.809917355
tradesparky	JA	JAM72S20-455	2112	1052	455	105	2.22	231	911	21	9555	2205	4.333333333
tradesparky	JA	JAM72S30-545	2278	1134	545	122	2.58	224	1059	21	11445	2562	4.467213115
tradesparky	Trina	TSM-425W	1762	1134	425	137	2	322	819	21	8925	2877	3.102189781
tradesparky	canad	CS6R-435H	1722	1134	435	122	1.95	280	801	21	9135	2562	3.56557377
tradesparky	DMEG	DM410M10	1708	1134	410	82	1.94	200	794	21	8610	1722	5
cityplumb	Longi	LR4-60HIH-370M	1755	1038	370	72.6	1.82	196	747	21	7770	1524.6	5.096418733
cityplumb	Longi	LR5-54HTH-435M	1722	1134	435	112	1.95	257	801	21	9135	2352	3.883928571
cityplumb	Longi	LR5-54HTB-425M	1722	1134	425	108	1.95	254	801	21	8925	2268	3.935185185
cityplumb	Sharp	Nujc400B	1722	1134	400	87	1.95	218	801	21	8400	1827	4.597701149

 

Edited August 27, 2023 by puntloos

[puntloos]

Fun fact - JA Solar 410 is 300 inc on Amazon and 334 inc on ebay

Those are some nice markups if you don't know where to look

 

 

[puntloos]

Oh, cef.co.uk is even cheaper.

 

Updated:

 

Shop	Brand	Type	SizeY	SizeX	Watt	Price ex	m2	GBP/kWh	W/sqm	PanelEst	TotalW	TotalCost	TotalW/C
tradesparky	JA	JAM54S30-410	1722	1134	410	80.76	1.95	197	801	21	8610	1695.96	5.08
easypv	Euren	Zebra 340	1684	1002	340	121	1.69	356	692	26	8840	3146	2.81
tradesparky	JA	JAM72S20-455	2112	1052	455	105	2.22	231	911	21	9555	2205	4.33
tradesparky	JA	JAM72S30-545	2278	1134	545	122	2.58	224	1059	21	11445	2562	4.47
tradesparky	Trina	TSM-425W	1762	1134	425	137	2	322	819	21	8925	2877	3.1
tradesparky	canad	CS6R-435H	1722	1134	435	122	1.95	280	801	21	9135	2562	3.57
tradesparky	DMEG	DM410M10	1708	1134	410	82	1.94	200	794	21	8610	1722	5
cityplumb	Longi	LR4-60HIH-370M	1755	1038	370	72.6	1.82	196	747	21	7770	1524.6	5.1
cityplumb	Longi	LR5-54HTH-435M	1722	1134	435	112	1.95	257	801	21	9135	2352	3.88
cityplumb	Longi	LR5-54HTB-425M	1722	1134	425	108	1.95	254	801	21	8925	2268	3.94
cityplumb	Sharp	Nujc400B	1722	1134	400	87	1.95	218	801	21	8400	1827	4.6
renogy	renogi	RNG-50D-SS-UK	581	509	50	54	0.3	1080	121	21	1050	1134	0.93
renugen	jinko	Eagle 315Wp	1650	992	315	77	1.64	244	671	26	8190	2002	4.09
renugen	jinko	Eagle 335Wp	1684	1020	335	87	1.72	260	704	26	8710	2262	3.85
cef	longi	LR5-54HIH-410M	1722	1134	410	80	1.95	195	801	21	8610	1680	5.13
cef	trina	DE09.08R	1762	1134	425	88	2	207	819	21	8925	1848	4.83
cef	longi	LR4-72HIH	2094	1038	450	90	2.17	200	891	21	9450	1890	5
cef	longi	LR5-66HIH-500M	2093	1134	500	106	2.37	212	973	21	10500	2226	4.72
Not Yet in UK	longi	LR5-72HBD-555M	2278	1134	550	140	2.58	255	1059	21	11550	2940	3.93

 

It's pretty clear that JA Solar and Longi are neck and neck. Effectively you want JA JAM72S<AA>-<BBB> or Longi LR5-<XXXXX><YYY>M for best value for money.

 

[puntloos]

 

did you know JA Solar already has a 630W panel? Right there on alibaba..

https://www.alibaba.com/product-detail/JA-Solar-Panel-630W-N-type_1600925740930.html

 

Weird how they calculate per watt, but it works out to 99 GBP per panel ex shipping, ex vat, ex bribing communist party so let's say 125/panel?

 

Updated:

Shop	Brand	Type	SizeY	SizeX	Watt	Price ex	m2	GBP/kWh	W/sqm	PanelEst	TotalW	TotalCost	TotalW/C	URL
tradesparky	JA	JAM54S30-410	1722	1134	410	80.76	1.95	197	801	21	8610	1695.96	5.08
easypv	Euren	Zebra 340	1684	1002	340	121	1.69	356	692	26	8840	3146	2.81
tradesparky	JA	JAM72S20-455	2112	1052	455	105	2.22	231	911	21	9555	2205	4.33
tradesparky	JA	JAM72S30-545	2278	1134	545	122	2.58	224	1059	21	11445	2562	4.47
tradesparky	Trina	TSM-425W	1762	1134	425	137	2	322	819	21	8925	2877	3.1
tradesparky	canad	CS6R-435H	1722	1134	435	122	1.95	280	801	21	9135	2562	3.57
tradesparky	DMEG	DM410M10	1708	1134	410	82	1.94	200	794	21	8610	1722	5
cityplumb	Longi	LR4-60HIH-370M	1755	1038	370	72.6	1.82	196	747	21	7770	1524.6	5.1
cityplumb	Longi	LR5-54HTH-435M	1722	1134	435	112	1.95	257	801	21	9135	2352	3.88
cityplumb	Longi	LR5-54HTB-425M	1722	1134	425	108	1.95	254	801	21	8925	2268	3.94
cityplumb	Sharp	Nujc400B	1722	1134	400	87	1.95	218	801	21	8400	1827	4.6
renogy	renogi	RNG-50D-SS-UK	581	509	50	54	0.3	1080	121	21	1050	1134	0.93
renugen	jinko	Eagle 315Wp	1650	992	315	77	1.64	244	671	26	8190	2002	4.09
renugen	jinko	Eagle 335Wp	1684	1020	335	87	1.72	260	704	26	8710	2262	3.85
cef	longi	LR5-54HIH-410M	1722	1134	410	80	1.95	195	801	21	8610	1680	5.13
cef	trina	DE09.08R	1762	1134	425	88	2	207	819	21	8925	1848	4.83
cef	longi	LR4-72HIH	2094	1038	450	90	2.17	200	891	21	9450	1890	5
cef	longi	LR5-66HIH-500M	2093	1134	500	106	2.37	212	973	21	10500	2226	4.72
Not Yet in UK	longi	LR5-72HBD-555M	2278	1134	550	140	2.58	255	1059	21	11550	2940	3.93
Alibaba	JA	JAM72D42	2465	1134	630	125	2.8	198	1146	21	13230	2625	5.04	2249 USD

 

OK I should go to bed. Sorry for many posts, but buildhub doesn't let me edit.

[JohnMo]

Remember to check the max amps and voltage of each string doesn't exceed what the inverter can allow. Big panels need careful selection of inverters as the amps can be high.

 

data for the 410W JA panels - a series string volts increases and amps remains the same. 

 

[joth]

13 hours ago, puntloos said:

I guess the challenge is that your claim seems to be true for DIY systems (easyPV for example) but the cost the installers I ran across are charging basically overrides that claim in end cost

My 2x cost and 0.5x efficiency was based solely on this is what GB sol told me when I spoke to them, and was for the installed price of tiles vs infinity full roof of solar.

This was 4 years ago so prices may have changed

Also:

- their infinity roof is quite poor kW/m2 so tiles may come out even worse when compared to modern high efficiency panels

- they were very clear in saying infinity roof can only be installed by their own installation team (sister company), so if there's any challenges at all with DIY installing the tiles I'm sure they'd be very honest and direct it saying so

 

[puntloos]

Updates:

 

1/ I made a mistake in my spreadsheet calculating the watt/sqm, but thankfully the final 'value for money' column and therefore the conclusions stand. Here's the corrected one:

Shop	Brand	Type	SizeY	SizeX	Watt	Price ex	m2	W/GBP	W/sqm	PanelEst	TotalW	TotalCost	URL
Alibaba	jingsun	JAM132D-710	2384	1303	710	126	3.11	5.63	229	18	12780	2268	2285 GBP
cef	longi	LR5-54HIH-410M	1722	1134	410	80	1.95	5.13	210	21	8610	1680
cityplumb	Longi	LR4-60HIH-370M	1755	1038	370	72.6	1.82	5.1	203	21	7770	1524.6
tradesparky	JA	JAM54S30-410	1722	1134	410	80.76	1.95	5.08	210	21	8610	1695.96
Alibaba	JA	JAM72D42	2465	1134	630	125	2.8	5.04	225	18	11340	2250	2249 USD
tradesparky	DMEG	DM410M10	1708	1134	410	82	1.94	5	212	26	10660	2132
cef	longi	LR4-72HIH	2094	1038	450	90	2.17	5	207	21	9450	1890
cef	trina	DE09.08R	1762	1134	425	88	2	4.83	213	21	8925	1848
cef	longi	LR5-66HIH-500M	2093	1134	500	106	2.37	4.72	211	21	10500	2226
cityplumb	Sharp	Nujc400B	1722	1134	400	87	1.95	4.6	205	21	8400	1827
tradesparky	JA	JAM72S30-545	2278	1134	545	122	2.58	4.47	211	21	11445	2562
tradesparky	JA	JAM72S20-455	2112	1052	455	105	2.22	4.33	205	21	9555	2205
renugen	jinko	Eagle 315Wp	1650	992	315	77	1.64	4.09	192	26	8190	2002
cityplumb	Longi	LR5-54HTB-425M	1722	1134	425	108	1.95	3.94	218	21	8925	2268
Not Yet in UK	longi	LR5-72HBD-555M	2278	1134	550	140	2.58	3.93	213	21	11550	2940
cityplumb	Longi	LR5-54HTH-435M	1722	1134	435	112	1.95	3.88	223	21	9135	2352
renugen	jinko	Eagle 335Wp	1684	1020	335	87	1.72	3.85	195	26	8710	2262
tradesparky	canad	CS6R-435H	1722	1134	435	122	1.95	3.57	223	21	9135	2562
tradesparky	Trina	TSM-425W	1762	1134	425	137	2	3.1	213	21	8925	2877
easypv	Euren	Zebra 340	1684	1002	340	121	1.69	2.81	201	26	8840	3146
renogy	renogi	RNG-50D-SS-UK	581	509	50	54	0.3	0.93	169	21	1050	1134

 

An important thing to notice therefore is that the W/SQM is surprisingly similar for all these cells. Only that jingsun on at the top seems to be an outlier and ha, I am not sure I trust those.

 

W/GBP is the column to pay attention to, and that still says that longi is probably the best value for money, JA not far behind. It might matter to you which panels barely fit, and which ones barely don't fit if your roof dimensions are teetering on the edge of fitting just-one-more-panel, like mine. Yep.

 

2/ I noticed that while GSE seems pretty common, I believe it has some limitations that I find a bit annoying

1. It has fixed tray sizes so uncommon panels won't fit, or you will be using more space than you need
2. It does not allow you to combine horizontal and vertical trays, at least they won't be nicely connected.

 

Perhaps Renusol ISSE is more flexible but I cant seem to ind anyone selling them. Tradesparky does have _some_ renusol stuff but I think it's missing that ISSE stuff again. 

 

 

Edited August 28, 2023 by puntloos

[puntloos]

Here's the difference between using the larger panels and the 'standard' panels:

Mixing Portrait+Landscape, 450M (Big - 2094x1038): 10800W

Landscape only, 450M (Big - 2094x1038): 9900W

Mixing Portrait+Landscape, 410M (Standard - 1722x1133): 9840W

Portrait Only 410M (Standard - 1722x1133): 9430W

 

All in all even the 'standard portrait' approach is not terrible, and there are good tolerances around obstructions, windows etc.

Perhaps I should just stick to standard portrait...

 

 

 

 

[JohnMo]

Obvious question is why do you have to fill your roof, if your not careful it will just look like the dogs dinner - a mess. Are you just trying to be too greedy?

 

If it's not symmetrical and balanced it's not going to look right. What about 2 rows of 450W in landscape under the roof windows, that would give 16 panels or 7.2kW. Adding more may sound good - but if your sketches are anything to go by, it looks a real mess.

 

 

 

[puntloos]

20 minutes ago, JohnMo said:

Obvious question

Nothing is obvious for an amateur, I appreciate you taking the time for this!

 

20 minutes ago, JohnMo said:

is why do you have to fill your roof, if your not careful it will just look like the dogs dinner - a mess. Are you just trying to be too greedy?

 

If it's not symmetrical and balanced it's not going to look right. What about 2 rows of 450W in landscape under the roof windows, that would give 16 panels or 7.2kW.

 

Well, as mentioned the landscape ones are too big, there are no GSE trays for this. (which brings us back to the discussion if one needs GSE at all... 

 

20 minutes ago, JohnMo said:

Adding more may sound good - but if your sketches are anything to go by, it looks a real mess.

Other than some of the guiding lines it actually is symmetrical, no?

 

Here's a bit more tidy version:

Here's a real picture that's "curving around a window'.. I'm not sure if it's "ugly" or "okay" but this roof is pretty far off the ground so I'm not sure it'll be too horrible..

 

 

 

And for what it's worth it's pretty similar to a design we got from a professional installer, who is proposing 30,000 for this one. (ignore the panels on the flat roof)

 

Edited August 28, 2023 by puntloos

[JohnMo]

10 minutes ago, puntloos said:

pretty similar to a design we got from a professional installer,

All nicely symmetrical, except the one landscape panel, which I would omit. I take it they are smaller panels also

5 minutes ago, puntloos said:

Here's a bit more tidy version

Would suspect you are too close to the edge on the outbound corners, because you need tiles for the ridge tile to sit on and have correct support.

 

 

[SteamyTea]

I may have missed this, but can you connect ~10 kWp, is easy with 3 phase but then that introduces self consumption challenges.

 

Side question, how thick are the roof battens and the tiles?

Edited August 28, 2023 by SteamyTea

[puntloos]

3 hours ago, SteamyTea said:

I may have missed this, but can you connect ~10 kWp, is easy with 3 phase but then that introduces self consumption challenges.

 

Side question, how thick are the roof battens and the tiles?

Forticrete minislate on battens and counter battens
Air breather membrane Klober Permo or similar
100mm Celotex or similar PIR insulation
197mm truss chord as per engineers' design
200mm Earthwool/Glasswool insulation fill in between
Vapour barrier membrane
25mm air gap
12.5mm plasterboard finished with 3mm skim and paint

 

with the minislate:

Dimensions
Length : 270mm.
Hanging length : 243mm.
Width : 495mm.
Cover width : 470mm.
Pitch : 22.5° to 29° pitch.

30° to 70° pitch.

Batten size : 38mm x 25mm for spans up to 450mm.

[puntloos]

One more update. Here's my final math:

 

Item	Brand	Model	count	Power	TotalPower	Cost exVat	Total		Total if 32 panel
Panel	JA	JAM54S-30-420-GR-BF	23	420	9660	83	£1,909		£2,656
Inverter	Solax	X3-HYBRID-G4-12.0	1	12	12	1953	£1,953		£1,953
Battery	Pylontech force 14.21	Pylontech force 14.21	1	14.21	14.21	4397	£4,397		£4,397
Mounting kit	GSE mounting kit	GSE mounting kit	23			£98.00	£2,254		£3,136.00
						Subtotal Mat	£10,513		£12,142
						OH/P	£841		£971
Install	est 4000						£4,000		£5,565.00
						Total ex VAT	£15,354		£18,678

 

 

Sooo that seems to be half the price of my faithful installers and much better 'side gear' - 14kW battery, 12kW inverter.

That's all from https://www.itstechnologies.shop/products/420w-mono-perc-half-cell-mbb-black-frame-gr-mc4-solar-panel - they have all components I need, and that fit together (some inverters only want to work with their own brand battery etc). Might even get a small discount for doing it all together. 

Edited August 28, 2023 by puntloos

[Big Jimbo]

`So , am i right in thinking that the GSE mounting kit, (is that trays for in roof ?) is more expensive than the actual solar panels ? You have done a lot of work, which will be useful for others.

[JohnMo]

I bought my GSE trays from ITS, they were £25 each. I would double check your quantity of the sundry bits from GSE. £98 for each panel doesn't sound right.

 

Here is my list of bits for 10 panels

 

 

[puntloos]

Basicaly GSE is now one kit - https://www.itstechnologies.shop/products/gse-in-roof-mounting-system-portrait?_pos=1&_psq=gse&_ss=e&_v=1.0 - 98 GBP. 

It is kinda outrageous that it's more expensive than a panel.

[JohnMo]

Not here this panel is £29. But all parts available separately 

 

https://www.tradesparky.com/solarsparky/mounting/gse-integration/mounting-plates-frames/gse-halfport16501135-1610-1800x1130-1135?gclid=CjwKCAjwrranBhAEEiwAzbhNtYXjvlOJ8rSRX3slCB3ccQdXHEAiGgPUjaA15HDbvyw4lMClpprwBxoCH7oQAvD_BwE

Edited August 29, 2023 by JohnMo

[puntloos]

8 minutes ago, JohnMo said:

Not here this panel is £29. But all parts available separately 

 

https://www.tradesparky.com/solarsparky/mounting/gse-integration/mounting-plates-frames/gse-halfport16501135-1610-1800x1130-1135?gclid=CjwKCAjwrranBhAEEiwAzbhNtYXjvlOJ8rSRX3slCB3ccQdXHEAiGgPUjaA15HDbvyw4lMClpprwBxoCH7oQAvD_BwE

 

https://www.cef.co.uk/catalogue/products/5178047-half-portrait-frame-1650-1135

22.27 😃

 

But I still frankly haven't heard a good reason why to do GSE in the first place  - what's your take on that discussion? Piece of plastic, nail the panels through it, Bob's your uncle?

[JohnMo]

8 minutes ago, puntloos said:

Piece of plastic, nail the panels through it, Bob's your uncle?

You could - I wouldn't - it's a bodge.

 

GSE panels have correct drainage and ventilation, cable routing and wind load design. They stop the ingress of water, and once you get your head around the install, very simple to install.  If the panel flies off in high wind gse get the blame, bodge job you do. PV panel is basically a pane of glass in a frame, if it hits from a roof, leave that to the imagination.

 

The GSE panel is £30, fixing and trim piece cheap also.

 

Or don't integrate, install slates or tiles and roof bars and hooks.

 

Do it properly once.