help with solar pv - south west london

django01

Hi Everyone,

I’ve been thinking about getting solar panels installed at my place and stumbled on this forum – what an amazing find! I’ve learnt so much from reading all the posts. I have got two quotes so far and the prices I have received are (1) £9700 for a 3kw system (2) 7300 for a 4kw system. Both solutions were string inverter based solutions (growatt). This seems a bit pricey to me. I am based in South West London. I’ve been through the solar PV FAQ. Appreciate any advice on this.

Exiled_Tyke

A short reply (it's late).

1. Post as much detail as you can on the quoted systems on here and there will be plenty of people to give you good advice on what you have been told.

2. Use http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php?lang=en&map=europe to compare estimated generation to the quotes which will help you determine the integrity of those quoting!

As I am sure you already know, you'll get great advice here, so don't be afraid to ask any questions and test the quotes you have been given to the full.

tunnel

django01 wrote: »

Hi Everyone,
I have got two quotes so far and the prices I have received are (1) £9700 for a 3kw system (2) 7300 for a 4kw system. Both solutions were string inverter based solutions (growatt). This seems a bit pricey to me..

Blimey, your not wrong. If they included battery back up I'd have said excellent price but for stand alone system.....noooo.
Aim for the price to start with a 4 for a 4kWp system and do as ET says, post the details on here.

django01

Thanks Exiled Tyke and tunnel. I hope this is detailed enough without being boring.

The proposal for the 4kw system was the clearest of the lot. It involved 15 X 265 w split across 2 roofs. 1 south facing (-7 degree) (8 panels) and the other east facing (- 97 degree) (7 panels). The estimated system output is 3501 kw and they are in line with what PVGIS indicates. Shade factor is 1 for both the roofs. The price is for:

15 Canadian Solar CS6P-260 I 265M All Black panels
1 Zeversolar 3680 inverter
1 Zeversolar power monitoring unit
15 panel inclined roof plain tile mounting system
single phase total generation meter
2 X scaffolding
DC & AC isolators, armored cable, MC4 connectors, switches etc.

£7300/-

The ROI calculation was very balanced and estimated a 13 year payback. The company seems to be very competent. My concern is only with the high price.

I tried reaching out to 2 companies via e*ay and most don’t service this market, London. Are London prices for solar PV 20% higher?

Another gave me a verbal quote of 4kw system 14 panels of now defunct Sun Edison + solar edge £5950. Should I chase him down to get the quote in writing, given the Sun Edison warranty is pretty much worthless?

Thanks again for your help.

purple_hamster

Wow. I'm getting quotes (NE London) and for a 4kw, they've all been under (some just under) £5k. My most expensive quote has been just under £7k for 5.5kw.

I was given a quote for Sun Edison, but TBH the guarantee is important to me. I'm not a risk taker and would worry about shelling out that money and then having them break down. I suppose you could take a chance. Or ask them if they could quote for a different panel.

django01

Thanks Purple Hampster..
Any chance you could PM me the names of the people who quoted for you. Please..

I am equally risk averse about panels !! Spoke to them and they are happy to supply a 4kw system using Solarworld panels and solar edge. Price £5950. The odd thing is they will only give a technical proposal after I give 25% advance. And then a surveyor will visit the site to give the technical proposal. Apparently the advance is refundable if the proposal is not to my satisfaction.
Strange business practices in this city - London!!

Martyn1981

django01 wrote: »

£7300/-

The ROI calculation was very balanced and estimated a 13 year payback. The company seems to be very competent. My concern is only with the high price.

Hiya, best of luck with this project.

A 13yr payback must have a high leccy saving figure. You said you read the FAQ's, though they have my name on them, they are a collaboration of opinions from PV'ers. When I suggested amending the leccy saving amount a few years ago, the consensus was to leave it alone at £120 (£80-£160 range).

So FiT and export are ~£67/MWh, so that's £67 x 3.5MWh = £235 plus £120 in savings = £355pa.

£7,300/£355 = 20.6 years.

I appreciate it's index linked, which might knock a year or so off, but nowhere near 13 years, and you should really include the cost of a replacement inverter (perhaps £800 with fitting) during the life of the system (hopefully 30yr+).

The price needs to come down to £5k or less, if possible.

django01 wrote: »

The odd thing is they will only give a technical proposal after I give 25% advance. And then a surveyor will visit the site to give the technical proposal. Apparently the advance is refundable if the proposal is not to my satisfaction.
Strange business practices in this city - London!!

That sounds scary! If they want the business they should come round, assess and quote. Please be careful!

Mart.

Cardew

django01 wrote: »

The ROI calculation was very balanced and estimated a 13 year payback. The company seems to be very competent. My concern is only with the high price.

I tried reaching out to 2 companies via e*ay and most don’t service this market, London. Are London prices for solar PV 20% higher?

Another gave me a verbal quote of 4kw system 14 panels of now defunct Sun Edison + solar edge £5950. Should I chase him down to get the quote in writing, given the Sun Edison warranty is pretty much worthless?

Thanks again for your help.

So FiT and export are ~£67/MWh, so that's £67 x 3.5MWh = £235 plus £120 in savings = £355pa.

£7,300/£355 = 20.6 years.

Martyn's figures for income are more realistic.

However the unbridled enthusiasm for Solar - 'something for free!' - is making financial common sense fly out of the window.

To have an 'investment' that might simply return your capital expenditure in 13 years, let alone 20 years is absurd.

Even at the dismal interest rates now available, 2% on a long term account is available. So even a £5k bank investment will produce £100pa compounded interest. That to be deducted from the solar panel income. - and you still have the £5k in the bank.

The probability is that some repair(s) will be needed.

Then take the guarantee. Even if the panel manufacturers are still in business, the probability is that the installers will have moved on, or changed their name to escape any liability for previous work.(standard practice for years in the solar industry) Read this forum and elsewhere.

Even with an insurance backed guarantee, if a fault occurs on a panel/cabling etc, who is going to diagnose that fault? and what will it cost for just the diagnosis? Bear in mind that health and safety regulations restrict the work that can be carried out on a roof.

P.S. If your intention is purely to be 'Green' - ignore the above;)

django01

Thanks Martyn and Cardew... I am going to hold out for prices to come down under £5k.

Since the shading factor for my roof was low, I requested the vendor to swap out the solar edge system for a string. He offered a Growatt inverter and a discount of £350, taking the price down to £5600.

purple_hamster

I've had a few companies who've given me a verbal price and seem to only do a full spec quote if I pay a deposit. I've walked away from them.

I'll PM you the companies I'm considering. Although I am still waiting for quotes from two.

Martyn1981

Cardew wrote: »

To have an 'investment' that might simply return your capital expenditure in 13 years, let alone 20 years is absurd.

Even at the dismal interest rates now available, 2% on a long term account is available. So even a £5k bank investment will produce £100pa compounded interest. That to be deducted from the solar panel income. - and you still have the £5k in the bank.

Not true, as previously explained to you many times.

1. Yes there is the cost of capital (the 2% you mention) but the returns would earn this too, balancing out 2/3 of that part, plus the income streams are index linked, whereas inflation will mostly erode that interest (2% interest v's 2% inflation means the bank balance only treads water in real terms).

2. Do you still have the £5k or does the bank have it? To earn the interest, you can't touch it, if you touch it, such as buying something (a PV system perhaps) then you no longer have it. So having it and earning interest are two conflicting aspects when you think about it properly - if the bank enjoys the capital, you get the interest, if you enjoy the capital, there's no longer any interest.

3. You find a 20 year investment that returns the money after 13 years absurd - surely your neighbour would find you absurd if after 13 years they had the same bank balance as you, but also a PV system on the roof, and 7 more years of FiT income!

4. Having PV is fun, almost a hobby. Do you calculate return periods on expenditure for hobbies, holidays, new bathroom, new car?

5. It's not all about the money, this is after all the Green & Ethical section of MSE.

Cardew wrote: »

The probability is that some repair(s) will be needed.

Is it?

Mart.