Here's my Solar PV quote - your thoughts and comments please?

jimmyboy420

12 Sunpower 327W PV Panel
1 SMA Sunny Boy 3600TL-21 Dual Tracker Inverter
K2 on-roof mounting Kit: Roof Brackets, Rails and Panel Fixings
Electrical Kit: Cable, Switches, Meters & Hazard Labels

Total £ 7,542.08 inc VAT @ 5%

Estimated annual yield : 3747.42 kWhs

Annual Income & Savings :
Feed-in Tariff Payment : £ 558.37
Fuel Bill Savings : £ 287.05
Export Payments : £ 86.94
Total 1st years return : £ 932.36
Annual Tax Free Return : 12.36%

My roof is south south east facing, but has potential shading from a chimney on the west side of my roof, in the evenings. For this reason, they've suggested a Solaredge system, though I haven't heard how much the additional cost will be yet.

I'm also thinking of getting them installed flush with my roof tiles rather than on a mounting system This adds to the cost a bit. Any thoughts on this?

tunnel

Are you tied for space on your roof or can you get 16 panels up there, I ask as sunpowers are quite minty and you could get the price down with "normal" 250W panels.

Solaredge....bang on, have a system installed with it myself and can't fault it one bit. I have shading all year round and yesterday with that system generated approx 0.5kWh more.

Tunnel

jimmyboy420

Yes, I can only fit 12 panels and they'll be close to the chimney on one side.

I'm pretty much sold on solar edge now, but can you tell me how you know about the extra 0.5kWh.

And am i right thinking that equates to around 9pence?
So we're talking an additional cost of approx £300, nearly 10 years to pay back, which is ok.

tunnel

My system used to have an SMA sunnyboy inverter but I swapped it to solaredge. My panels would become shaded one by one from next door. With the SMA once the first panel goes down then the rest go with it yet the solaredge once the first panel goes to shade the rest keep working as normal.


My 0.5kWh came from working out what the first panel did compared to the rest which was 70W, 7 x 70 is 490 so nearly 0.5kWh. Once you have a system in and the online monitoring you'll completely understand.


Its a 2kWp system its retro fitted too, 8 panels


I'm on 46.8p a unit generated by the way.


Ps, your leccy savings are way too high in estimations, try working on £80-120

jimmyboy420

Thanks,

That's been calculated as half the units used at 15p per unit.

Unreasonable then?

jimmyboy420

Thanks,

That's been calculated as half the units generated at 15p per unit will be saved.

Unreasonable then?

tunnel

You'll find that most installers calculate it at 50% usage. It doesn't happen, unless you have an immersion tank and then you'd add an immersun switch or equivalent that would use any spare generation to heat your hot water tank.

Without one and you'll be looking at 20-30% usage, better if your home all day to plan your appliances.

jimmyboy420

Well I have timers...

tunnel

jimmyboy420 wrote: »

Well I have timers...

Can they look out the window when the clouds suddenly break for glorious sunshine for an hour, the hour before your timer is set to switch on.;)

Are you southern britain by any chance?

Have a look and play on here http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php

You can check what your expected generation is going to be, see if your quotes are correct

jimmyboy420

I'm southern England, yes. Why do you ask?

tunnel

http://re.jrc.ec.europa.eu/pvgis/apps4/pvest.php


Again as above, put your figures and location into here and see if your quoted generation figure matches up. You've been quoted fairly high so I assumed southern UK