Solar PV Quote Help

pinnks

A diverter is useful. There are a number of different types. I have the immerSUN with which I am very pleased. It also offers a monitoring system so you can see what you have generated, diverted, imported, exported and total house use. Trouble is the firm went out of business last year. The business was sold and the monitoring is working but I have no idea whether they have started selling again.

£450 seems a bit steep, let alone £700. The immerSUN was one of the most expensive. The units are/were about £250 plus £100 for the myimmerSUN monitoring. I negotiated it as an extra at no cost before signing.

All diverters work on the AC side. The have a CT clamp on the main cable near the meter (or two if you have the monitoring so you can measure generation) and switch on the diverter when you are exporting and divert whatever excess you have to the immersion heater (or any other resistive load like oil-filled radiators, underfloor heating etc etc). I can't see any reason whatsoever why a diverter would cost more with SE. There is no link between the two systems - SE is on the DC side and in the inverter; diverter is on the AC side.

Again, search the forum for immerSUN or iBoost and you will find loads of info.

jaminben

Cool... that's how I thought it should work so can't see why it's so expensive, I will quiz them on that.

My favourite quote is the system for £6037.50 but I've been trying to work out prices online to see if I can squeeze a little off as it's quite a jump from £4k to £6k using my rough costings. I realise that labour, cable, fittings, scaffolding etc need to be added but could someone fill in the blanks for the roof mounting system and cloud monitoring?

JA Solar JAP6-60 265W x 14 @ £149.90 = £2,098.60
Solar Edge P300 Optimisers x 14 & £47.28 = £661.92
Solar Edge SE3680H x 1 @ £600.00 = £600.00
iBoost hot water tank power diverter x 1 @ £700.00 = £700
Renusol VS Plus On roof mounting ?
Single Phase MID compliant Meter - Manually Read with wattnode cloud monitoring ?

My total so far:
£4,060.52

Their total:
£6037.50

EDIT
I'm also wondering why they've quoted me for a Solar Edge SE3680H Invertor as that has the capacity to handle 5700W maximum DC power where my system could only produce at 100% maximum 3710W.... is that correct (265W x 14 panels)?

pinnks

Don't forget scaffolding - £300 per roof - and labour. Probably 2 guys on the roof for a day and a sparks to connect everything.

smebay has the iBoost at about £250, so they are suggesting labour costs and a bit of wire (perhaps, as it simply sits between main distribution box and immersion and acts as a switch - chop the cable and connect the two ends to the relevant terminals in the diverter. £450 for no more than one hour's work for a sparks? Someone is extracting the Michael...

Inverter does sound a bit big, which is not a good idea as they work better when being pushed. You are right with your thoughts of 14 x 265 and you won't max that out very often, if at all. My 3,500 system peaks at about 3,300 on good days; the 1,750 system at about 1,600. I very occasionally see max generation for 10 to 20 minutes but not many times a year.

jaminben

Thanks pinnks, So if I were to add another £1000-£1500 to my total and get £5000-£5500 that would sound reasonable for that system. I'm wondering if they were to replace the JA Solar JAP6-60 265W panels with JA Solar Smart Module 315W JAP6(SE) panels and keep the price @ £6k if that would be a better deal for me as it would give me a 4.4KW (315W x 14) system and make better use of the invertor.

Martyn1981

jaminben wrote: »

EDIT
I'm also wondering why they've quoted me for a Solar Edge SE3680H Invertor as that has the capacity to handle 5700W maximum DC power where my system could only produce at 100% maximum 3710W.... is that correct (265W x 14 panels)?

hiya. the new se inverters, the hd wave models are increedible, and can handle massive over capacity from the dc side, but they are named for the ac side output, so you'd want one that can ouitput 3.68kw, to avoid any capping/waste.

so best to concentrate on matching the ac to kwp appropriately, not the dc figure, such as mine which is 3.58kwp and a 3.5kw inverter, even though it's rated for 5kw of panels if necessary.

if you use 3 rooves and perhaps go for 5 or miore kwp, then that 3.68kw inverter will still be perfect.

you're calcs on kwp are correct, but i'd suggest a minuimum 280wp per panel these days, and for a split system, stick as much pv up there as you can, so much of the costs are fixed, that the extra panels, labour, and railing get diluted, bringing down the cost/kwp as you go bigger.

jaminben

Thanks Mart, so the invertor they've quoted is good for the system. I guess it all boils down to the fact that if it's a good deal for £6k using those 265W panels?