Solar panel quote check please - Sunedison & Solar Edge

Aceshigh84

Hi,

I've just been reading through the solar panel discussion thread and people say to post details of quotes received for comparison and to ensure a good deal is achieved, so here goes.

I have been quoted £11,500 for a 6.84kWp system consisting of 24 x Sunedison Silvantis R 285w panels and solar edge.

This is to go on a east/west split roof, 12 panels on each aspect.

If I've done my maths correctly this comes out at ~£1.60/w, which is more than what CrazyCol's system on page 121 of the above thread works out at (£1.40/w including iBoost for his system)

I also have been offered enphase at an extra £1000, does this seem an appropriate cost?

Thank you

pw22

Hi,

I would say that price is rather high - the average price on here seems to be about £5k for a standard 4kw system. Of course there will be extra scaffold costs etc,

I would suggest getting another couple of quotes - if you post your rough location, then some posters on here may have installers that they recommend.

Hope this helps.

tunnel

Aceshigh84 wrote: »

Hi,

1)I have been quoted £11,500 for a 6.84kWp system consisting of 24 x Sunedison Silvantis R 285w panels and solar edge.

2)I also have been offered enphase at an extra £1000, does this seem an appropriate cost?

Thank you

1) As pw22 says, too expensive, to give you an idea my parents were quoted £10k for an 8kWp system at the beginning of last year. I'd say £7-£8k would be more in line with your requirements


2) Do you have any shading on either roof? If there's no shading there's no need for solaredge or enphase, a standard duel MPT inverter would suffice.

Aceshigh84

Thank you both.

As for shading, I've been quoted a shading factor of 0.87 (east) & 0.85 (west). I don't know if this is good or bad, I've got a tree directly opposite the front of the house across the road, I've never notice it cast a shadow any further than halfway up the drive.

I am inclined to steer away from "normal" string inverters as they are a single point of failure for the entire system - this is my belief, rightly or wrongly. Plus the horror stories regarding high voltage dc still generating from the panels even if the inverter is shut down.

The Solar edge system removes some of this (maybe unfounded) worry, but still has the spof in the central inverter.

The enphase system appeals, due to limiting spof to only individual panels, plus converting to ac almost immediately at the roof and being able to shut the panels down if necessary.

What are your opinions on maximising the installed capacity (cost allowing)? For example fitting 24 (or 26 space permitting) BenQ 330w panels to go to ~8kWp.

Aceshigh84

* edit *
Also with the shading, does the east/west transition not cast shadow from the rear of the roof across the front and vice versa during the day? Does this count?

Martyn1981

Aceshigh84 wrote: »

Hi,

I've just been reading through the solar panel discussion thread and people say to post details of quotes received for comparison and to ensure a good deal is achieved, so here goes.

I have been quoted £11,500 for a 6.84kWp system consisting of 24 x Sunedison Silvantis R 285w panels and solar edge.

This is to go on a east/west split roof, 12 panels on each aspect.

Thank you

Hi and welcome.

1. That sounds way too high. As others have mentioned, and you've spotted, some 4kWp systems are coming in at less than £5k (£1,250/kWp) and costs keep falling as size goes up, since a lot of costs are fixed. Even scaffolding will only increase a small bit for two rooves, not double.

So 6.84 x £1.25k = £8.55k seems a very reasonable starting point, which you should really aim to beat.

2. Have you discussed the system size with your DNO, do you have permission to go that big, what output will the inverter have? See section 10 of the PV FAQs regarding rules/issues of exceeding 3.68kW output (not kWp of panels).

Aceshigh84 wrote: »

The Solar edge system removes some of this (maybe unfounded) worry, but still has the spof in the central inverter.

3. If you have shading issues, then SolarEdge is excellent. I get your SPOF question, but with a standard warranty of 12 yrs and excellent efficiency rating, I don't think it matters too much. At least with an inverter failure, they are easier to access and replace.

Aceshigh84 wrote: »

What are your opinions on maximising the installed capacity (cost allowing)? For example fitting 24 (or 26 space permitting) BenQ 330w panels to go to ~8kWp.

4. If you want / need / can go bigger, then they're an option, but high efficiency panels cost more per Wp, so the cost will increase more than proportionately. You'll need to get multiple quotes, work out the income figures, then decide which options give you the best return on investment.

Back to an earlier point, have you any indication that the DNO will let you go bigger, do you have a 3 phase leccy supply? 8kWp, even split across two aspects is getting seriously big for a single phase supply.

Aceshigh84 wrote: »

Also with the shading, does the east/west transition not cast shadow from the rear of the roof across the front and vice versa during the day? Does this count?

5. Yes it counts, but will be included in generation estimates. See section 5 of the PV FAQs.

East, west or E/W should generate about 80% of what a south facing system would generate (at 35d pitch).

Mart.

Aceshigh84

Hi Mart,

Thank you for your response.

1) valid point, I'll go back and ask them to sharpen their pencil somewhat.

2) I've read about one person who went close to 10kWp on single phase, this was with western power if I remember correctly. With regards my dno (sp energy), their website states that connections slightly larger than 16A per phase is ok for connection to the local sub station. I need to phone up and just ask what sort of size they will allow for my location - 4, 6.8 or more kWp.

3) valid point. Do you think the extended warranty on the Solar edge inverter is worth it? I've read approx £500 to extend to 20 years.

One of the benefits of solar edge is that I can cap the export to 3.6kW, and then retrospectively ask for permission from the dno to go higher. From what I've read, I can still go with (for example) a 6.8kW system with capped export and I would still get paid the fit based on panel array size (at the 4-10kWp rate) and assumed 50% export of all kWh generated.

Is my concern regarding high voltage dc cabling running through the house valid? Or am I being overly cautious based on the safety & reliability of today's systems?

4) based on my rough calculations, I can fit 30 of the 285w JA Solar panels on the roof, that works out at 8.5kWp and based purely on panel cost gives the best £/w of £0.52/w. Beating both Panasonic and BenQ panels (which I can fit 24 of) in system panel cost and system output. This is all based on the list price +5% vat of the panels from Swithenbanks. I would assume "proper" installers can command better pricing for panels.

When using Crazy Col's system as a guide, he had 14 x SunEdison panels fitted with solar edge for £5600, based on the panel dimensions, I could squeeze 30 panels, so just roughly double the cost, say £11k for 8.5kWp equalling ~£1.30/w for total system. Does this seem competitive?

michaels

Looking online the extra cost for solar edge seems to be £30 per panel plus possibly slightly longer install times.

WE are having a dual aspect 4kw system installed on Thursday with 14 285w serphim panels, a SMA inverter and an iBoost for 4800 all in.

tunnel

Aceshigh84 wrote: »

3) valid point. Do you think the extended warranty on the Solar edge inverter is worth it? I've read approx £500 to extend to 20 years.

Why bother extending when the standard warranty is 12 years and a new inverter costs around £500, the money is better in your account rather than paying for a new one up front when there's a possibility that the inverter may last the 20 years anyway.

michaels wrote: »

Looking online the extra cost for solar edge seems to be £30 per panel plus possibly slightly longer install times.

It's not £30 a panel difference though. An SMA inverter is around £700, solaredge and PO's come to around £1000. No time difference for install as they're just push connectors, something that has to be done when connecting panels up anyway.

Martyn1981

Aceshigh84 wrote: »

Hi Mart,

Thank you for your response.

1) valid point, I'll go back and ask them to sharpen their pencil somewhat.

2) I've read about one person who went close to 10kWp on single phase, this was with western power if I remember correctly. With regards my dno (sp energy), their website states that connections slightly larger than 16A per phase is ok for connection to the local sub station. I need to phone up and just ask what sort of size they will allow for my location - 4, 6.8 or more kWp.

3) valid point. Do you think the extended warranty on the Solar edge inverter is worth it? I've read approx £500 to extend to 20 years.

One of the benefits of solar edge is that I can cap the export to 3.6kW, and then retrospectively ask for permission from the dno to go higher. From what I've read, I can still go with (for example) a 6.8kW system with capped export and I would still get paid the fit based on panel array size (at the 4-10kWp rate) and assumed 50% export of all kWh generated.

Is my concern regarding high voltage dc cabling running through the house valid? Or am I being overly cautious based on the safety & reliability of today's systems?

4) based on my rough calculations, I can fit 30 of the 285w JA Solar panels on the roof, that works out at 8.5kWp and based purely on panel cost gives the best £/w of £0.52/w. Beating both Panasonic and BenQ panels (which I can fit 24 of) in system panel cost and system output. This is all based on the list price +5% vat of the panels from Swithenbanks. I would assume "proper" installers can command better pricing for panels.

When using Crazy Col's system as a guide, he had 14 x SunEdison panels fitted with solar edge for £5600, based on the panel dimensions, I could squeeze 30 panels, so just roughly double the cost, say £11k for 8.5kWp equalling ~£1.30/w for total system. Does this seem competitive?

Ello.

I think it's worth you getting an idea of what kW inverter (not kWp of panels) might be allowed, before spending too much time working out max system sizes.

You mention capping, that's not just SolarEdge, you can choose a 3.68kW capped inverter from most suppliers. A 5kWp system spread 2.5E and 2.5W wouldn't cap too much on a 3.68kW inverter. But as you go bigger, the generation losses (from capping will grow). My system can spend about 3 to 4 hours at 4.2kW in the May, June and July months, on a good day. If capped, the loss of 0.5kW for upto 4hrs per day, could add up. Note, those are sustained figures after panels have got hot and performance has dropped. For short periods (a minute or so) my systems can hit 5kW all in, but spikes aren't really worth worrying about in terms of total losses.

The SolarEdge warranty extensions are less than £500, here's an example of £150 + VAT 0-3.99kW and £188 + VAT 4-6kW.

I appreciate that DC can be a little scary, but it won't really run through your house, it 'just' goes to the inverter, before being converted to mains voltage AC.

VFM - the various 270-285Wp 'regular' panels, do seem to be very well priced compared to the high efficiency panels, so long as you have the room. Back to para 1, if you can't go super big, then 5kWp(ish) of regular panels, such as the 285's would seem like a good idea.

Mart.

DanceKing_2

Aceshigh84 wrote: »

Hi,

I've just been reading through the solar panel discussion thread and people say to post details of quotes received for comparison and to ensure a good deal is achieved, so here goes.

I have been quoted £11,500 for a 6.84kWp system consisting of 24 x Sunedison Silvantis R 285w panels and solar edge.

This is to go on a east/west split roof, 12 panels on each aspect.

If I've done my maths correctly this comes out at ~£1.60/w, which is more than what CrazyCol's system on page 121 of the above thread works out at (£1.40/w including iBoost for his system)

I also have been offered enphase at an extra £1000, does this seem an appropriate cost?

Thank you

I am just about to start working for the two biggest companies in the UK that will be selling and installing Solar only just launched today EVEREST AND ZANUSSI operating jointly to give a 20 year warranty etc etc and their whole system comes to £8995 and Everest has used all the top quality products with the very latest technology etc etc.

It does not pay to install over 4KW system with government FIT tariffs from the training I've received as the Government penalise you. That is unless your going to use all the electric that is produced.