Solar PV Quote seems excessive

Ageing_Stick_Insect

Martyn1981 wrote: »

Hi Ray, the rates are upto 4kWp, then >4-10kWp.

So it's what you've got installed on your roof, not what it generates.

That's great, thanks Martyn.

Tunnel did say that, but with cloudier skies. On long sunny days, when all the washing and vacuuming has been done, you'll be exporting a lot of green leccy to your neighbours whilst simultaneously terrifying and entertaining the beach goers on the other side of the fence from Princess Juliana International Airport.

Mart.

There's a man who knows his airports! Haven't tried that one yet but Innsbruck is 'interesting'.

Got paper and a pencil out this morning and cut out bits of paper to match Panasonic 1.6 x 0.8 meter panels. Tried those over 3 roofs. I can maybe fit the following kWp panels. Trienergia are shown for comparison in brackets.

ESE - 6 x 240 = 1.44 (1.2)
WNW - 7 x 240 = 1.68 (1.2)
SSW - 4 x 240 = 0.96 (1.1)

That makes a total of 4.08kWp for Panasonic and 3.5kWp for Trienergia.

But the ESE is borderline and may fit only 5 dropping the P total to 3.84kWp.

It looks on paper as though the ESE and WNW roofs may favour Panasonic 1.6 x 0.8 whereas the SSW roof definitely favours the Trienergia.

That would cost out (using Swithenbanks.co.uk) as follows:-
Trienergia 14 full and 7 half (3.5kWp) = £2905.63
Panasonic 17 full (4.08kWp) = £3548.41
Tri / Pan mix of 13P, 4 full T and 3 half T (4.22kWp) = £3631.22)

Dividing cost by kWp (limiting to 4kWp) shows All Trienergia is cheapest at £830.18 / kWp and mixture of both is most expensive at £907.81 / kWp.

On those calculations it isn't worth going for either a mixture or all Panasonic unless the increased FIT payment etc. would make it worthwhile. Thoughts?

Martyn1981

Ageing_Stick_Insect wrote: »

There's a man who knows his airports! Haven't tried that one yet but Innsbruck is 'interesting'.

Watched vidoeclips of those planes coming in and skimming the runway fence, whilst beachgoers stare up. Brilliant!

Ageing_Stick_Insect wrote: »

On those calculations it isn't worth going for either a mixture or all Panasonic unless the increased FIT payment etc. would make it worthwhile. Thoughts?

Your calcs look good to me, so not great news. The problem is that both types of panel carry a price premium.

Ageing_Stick_Insect wrote: »

Got paper and a pencil out this morning and cut out bits of paper to match Panasonic 1.6 x 0.8 meter panels. Tried those over 3 roofs.

Whilst you're in full 'Blue Peter' mode, have a try with 1m by 1.3m panels. Sorry to labour the point, but these won't carry much of a price premium, though my assumption isn't being helped by the lack of sites selling them.

They should be relatively proportional to regular panels, so if £150 for 250Wp, lets be optimistic and guess at £120 ((£150/250Wp)*200Wp).

If you can get 19 or 20 on, then it just might improve things.

I think you might just get 3 landscape on the bottom row of the SSW, but can you get another 2 above, even 1 more on top again?

Also think that you might get 3 landscape on the bottom of the ESE, with 2 rows of 2 above, but the bottom and top rows might be too close to the ridgeline.

The WNW should mirror the ESE, but without having to get under the chimney, you might want to try panels portrait, to see if that helps.

Depending on what panels are available, 185Wp to 200Wp, you'll need 20 to 21 max. I wouldn't, even if you could, just sneak over the 4kWp as the 10% FiT drop will hurt this marginal system.

Hope I'm not sending you on a wild goose chase, and it all depends on whether 1.3m by 1m is a better jigsaw fit than 1.6m by 0.8m ...... and of course that they can be found at a reasonable £/Wp rate.

Last roll of the dice, perhaps?

Mart.

Ageing_Stick_Insect

Hi Martin,

Thanks for all that info. Before I start cutting up pieces of paper again can I ask about the 1.3 x 1.0 panels you recommended further up this thread against the 1.2 x 1.07 Trienergia ones.

Trienergia are advertised as monocrystalline whereas the Romag are Polycrystalin. Is that important? They are considerably cheaper than the Trienergia and I wonder if that's for a reason.

Ageing_Stick_Insect

Quick search found this site that describes the pros and cons of each type. http://energyinformative.org/best-solar-panel-monocrystalline-polycrystalline-thin-film/

Given mono are more efficient than poly for a given size they seem a better choice for my limited roof area. If I had a large rectangular roof poly would probably be the better choice as space is not an issue.

I'll still do the Blue Peter test this afternoon but in theory the more expensive monos seem the better choice.

Martyn1981

Ageing_Stick_Insect wrote: »

Hi Martin,

Trienergia are advertised as monocrystalline whereas the Romag are Polycrystalin. Is that important? They are considerably cheaper than the Trienergia and I wonder if that's for a reason.

Mono's are better than poly, not much, and opinions differ depending on country, but yes you should try for mono's.

The examples I gave, were just to prove that I'm not making it up. I suspect the very low prices reflect the numbers available, perhaps clearing stock.

My 1.3's are Sharp, YingLi also make them, and probably several/many more, but I'm completely failing to find any 'freely available' on any sites. Not a good sign.

However, the installer should have no problems sourcing them, if they are still being sold in the UK, and I'm not sure why the wouldn't be.

Bit of a 'Hail Mary' perhaps, but you've gone this far .......

[Edit: Why not ring a couple of the bigger companies, Swithenbanks, Navitron etc, and just ask for a quick cheeky chat about 1.3's, are they available etc etc. Assuming of course that the Blue Peter experiment works.]

Mart.

Ageing_Stick_Insect

Hi Martyn,

Things are happening fast! Just had a reply from my quoter with plans using the Panasonic panels.

He doesn't recommend mixing different makes because blacks differ and a mixture could look bad.

He now predicts he can get 6 P panels on the ESE, 5 on the SSW roof and 5 on the WNW one making a power total of 3.84kWp. Any more panels and we go over the limit.

He's done the costings for the Panasonic and I'm attaching them together with the Trienergia ones. Appreciate your thoughts. He's said he can do this job next week meaning I should make the deadline for 31/3 with the higher FIT. I'd need him to confirm that though.

Trienergia costings...



And the Panasonic ones...

jimmyboy420

Is it me, or are your costings not there?

Ageing_Stick_Insect

Jimmy,

Can you not see the two images showing the costings for each system?

Here is the proposed new layout.

tunnel

Hi Ray,

What sort of inverter does that include? I ask as for 16 panels retail price of around £3300 then it seems a little on the pricey side at £8250, nearly £5k for an inverter, scaffold and fixings + other bits(inc labour). And you've seen the price of inverters at retail too so there's no pulling the wool over your eyes.

Can you not get someone else in to quote it with the same setup?

Ageing_Stick_Insect

Hi tunnel,

It's the SolarEdge, precise model to be determined. Each panel can be monitored via included software and it has a 12 year warranty. But he also has to provide individual power optimisers at £40 x 16 so that's £640 or so.

I appreciate I'm paying a premium for Panasonic and SolarEdge but they are amongst the top makes. I figure I'm only installing once so might as well do it with quality kit.

Take your point about another quote but this chap was £2K below another for Trienergia and I'm sure he'll drop a little with persuasion.

My main concern is the difference in estimated energy production with his 11.55% higher than the PVGIS calculator. I've asked him for his source.

You'll appreciate that in that £5K he has to make a profit. I'm guessing around £1K. That doesn't seem unreasonable does it?

Bear in mind the cost is pushed up by panels across 3 roofs and Panny and SolarEdge kit which is more expensive.