Solar PV Quote seems excessive

tunnel

Understood with the kit, i can vouch for solaredge as i have it on one of my systems, i also understand about the profit part but prices you're looking at are retail and not trade which should be hopefully considerably cheaper to someone with a trade account/buys in bulk.

Ask him to drop to £7.5K inc VAT(or less) and then you'll take the install next week:D

Ageing_Stick_Insect

johnel wrote: »

Going back to the above about pricing. I just had a 16 panel microinverter system fitted for £7000. German panels plus Enphase inverters. We got quotes ranging from £5999 for cheap panels with cheap inverters, right up to £9200. Some did not even talk about the inverter options and only went for the big box inverters. Best to do your homework and ask for references. The scaffolding is a bit of a scam too. Some wanted up to £500 on top. The one we finally used quoted £200 on top, but the guys said they didn't need it and we got it knocked off the bill.

John, my quote is definitely in the upper range so I will test his resolve once a few questions are answered satisfactorily. Did that £7K include VAT? My quote hasn't been itemised by cost so I suspect some things are proving expensive. I'll ask if he can break down the cost as the first quoter did.

Is your install on a single roof or not? That's bound to affect final cost.

Ageing_Stick_Insect

I've had a reply from my quoter regarding the disparity with estimated power output. I won't quote the whole message. This is the relevant bit...
Anyone quoting PVGIS as their source is not MCS compliant – you will notice the shading horizon graph attached to my forecasts, and that has been introduced to make forecasting more accurate for the customer.
Having said that, the radiance spreadsheet (I’ve attached a copy because I’m sure you’d love to have a play with it!) is based on standard string inverters and mono or polycrystalline modules. There is no provision to accurately add in the extra factor that hybrid technology, power optimisers and micro-inverters bring to the yield.

That reassures me that there is a sound basis to his numbers and that the PVGIS calculator is perhaps a general one rather than specific to my install.

Regarding knocking him down to £7K that might be too much to ask. He's increased the price purely on the difference between Trienergia and Panasonic but I will consider what is a fair price quoting the retail cost of panels and inverters etc. and see how flexible he is.

EricMears

Afraid the 'MCS compliant' figures that people are forced to tell you are notoriously unreliable ! According to them, the same system would produce the same output whether you fitted it in Penzance or Inverness.


PVGIS is far more accurate as it takes into account your actual position as well as letting you specify exact angles of the panels. It's a flaw in the MCS system that they ignore PVGIS in favour of the older model but most installers would be aware of that and would give you the official figure (as they're obliged to) AND the more realistic one.


Most people writing in this forum report reasonably good correlation with PVGIS - but of course even that is heavily dependent upon the weather (which no model is going to get right).

Ageing_Stick_Insect

Eric,

The spreadsheet he sent me included separate sheets for various cities around the UK. So it's not a one-size fits all. There was a sheet specifically for Manchester.

As I said in my earlier message the PVGIS calculator does not differentiate between the different types of system and the Panasonic Hybrid is definitely one of the more efficient. Point taken about the actual weather though. That's the one thing we can't forecast.

Martyn1981

Hiya Ray, that's interesting, all of it. Lot's of posts to catch up on, and I immediately got a little scared at the generation figures, but glad to see that, that has been addressed.

As Eric says, lots of us like PVGIS, as it seems pretty damn spot on, and is extremely easy to use. I like to play it safe, and when chatting to folk like yourself, always try to play the numbers down a bit, to build in a safety buffer - I think you've noticed - repeatedly.

Could the installer be correct, well, my WNW SolarEdge system does seem to be performing about 5% better than my normal ESE system (relative to target, not each other), so that's a good sign, and the WNW does have more shading. It could be all the clever stuff it does, or simply that the inverter is about 5% more efficient.

Next, there are claims that those Panasonics (and other hybrids) are more efficient in low sun generation. I think I've read 10% claimed (possibly), but let's say low sun (as in poor weather) is only 10 or 20% of good sun, then 10% gain is only 1 or 2%, but every little counts. So whilst I have to admit to knowing nothing about whether or not the installer is right, I suppose there could be some justification, and I have been told before that the default losses on PVGIS are a bit high.

Next, still looking to save you a few quid, does your WNW need to match the other 2 rooves, especially as it's less visible from the front (?). It's looks like there is enough space to widen those panels from 800mm to 'normal' 1,000mm. If so, then again using Swithenbanks retail prices simply as a comparison, the Panasonics are £209 for 240Wp. I only clicked randomly, but found Hyndai 250Wp for £150, Jetion 250Wp for £140, and LG 265Wp for £166, giving you 50 to 125Wp extra and savings of £300 £350, and £215 respectively.

As the system will be SolarEdge, you can mix and match panels.

To get the higher FiT, you have to get a completed application to your FiT provider before the end of the month, not just the install. When they get it, you need to get them to check it asap to confirm it's complete and correct, this doesn't mean they've issued you a contract, just confirmed that they had the complete application before the deadline.

Mart.

Ageing_Stick_Insect

Martyn,

I'll reply in full later but first wanted to see if I could achieve a £7K price by costing each element myself. If I'm going to negotiate with him I need to do so knowing roughly how much each part of the install is going to cost. If I just threw a number at him he could say "how did you reach that amount?" and if I couldn't answer I'd dramatically weaken my bargaining position.

So here's what I think it would cost See what you think...

16 Panny @ £208.73 = £3340
16 Solaredge optimisers @ £44.69 = £715
1 Solaredge inverter = £813.29
Clamps, isolators,cabling and meter = £250 approx.
Total = £5118
Less 10% for trade prices reduces it to £4606.

Scaffolding £500
Labour 28hrs @ £50 / hr = £1400
Sub-Total = £6506
VAT @ 5% = £325
Total before profit = £6831.

Assume profit of £600 makes the total £7431.

Clearly £7K is not a realistic figure for my install. I'm guessing that people who may that have a simple roof with all panels on one side and have chosen lesser quality panels and inverter.

So I think a fair price would be around £7400. Feel free to pull my argument to pieces.

Ageing_Stick_Insect

And I've just remembered tunnel's message earlier today where he also suggested £7.4K so it looks like my sums are pretty good and tunnel is a mastermind!

tunnel

I'd like to think that if they'd be charging you 28hrs @ £50 then their profits are included in that part alone. You can guarantee the guys doing the install aren't getting paid that rate(more like £10hr). That would be 28hrs @ £40 profit=£1120


Drop your assumed £600 profit off and work more towards £6800-£7k and I'd say your in the right ball park for all the kit you've listed.

Ageing_Stick_Insect

tunnel, is it realistic to drop labour so much when tax and NI has to be deducted from the employee?

What is a decent hourly rate after tax etc. I'll double it to include tax etc.