Solar

Martyn1981

EricMears wrote: »

I agree that a 7kWP system should all be paid at the lower FIT rate. Unless of course you do what Martyn did and fit a 4kWP system first then add a second system of 3kWP at a later date (and I don't think there's any rule that would stop you putting all 7kWP worth on the roof at once, installing & registering 4kWP immediately then registering the 'extension' a couple of weeks later - but seek proper advice rather than relying on my guess !)

@pvforme. Hiya, following on from Eric here, and I'm also stating that this is just a guess - so for goodness sake don't assume any of this is right.

This is just a thought exercise (as my brain is now in gear), so how might it work?

Ok, to do a 4 + 3 install, you'll need 2 separate MCS certs, and presumably 2 visits from the installer. To minimise costs, my guess would be:-

Install 4kWp on one string, and 3kWp on another string, then using an inverter (such as the Aurora PVI-6000-TL-OUTD with a DC max of 6.2kW) the 4 string is wired up, but the 3 string is left hanging (literally).

This way, for the second commissioning, there won't be any need for scaffolding, wiring runs etc etc, just connecting up the second MPPT (which co-incidentally have a max of 4kW DC each), which should take minutes.

Problems:

1. How much will the installer charge, how much is he (or she) charged for each MCS registration.

2. How long before you can commission the 'extension' - would you have to wait until the original FIT application has been received, processed, contract sent to you, signed and returned, and registered. I don't know how long this takes now, but a year or so back it was taking around 3 months for some.
If you apply for an extension sooner, will it just get lumped together with the original, and automatically become one 7kWp install. I'm blank, absolutely no idea how this bit would work.

3. Is it ok to do this?

4. Is it worth it:-
assuming 6,500kWh's pa, we have
6,500*13.99p = £909 v's
3,700*15.44p = £571 + 2,800*13.99p = £392 total £963
so an extra £50 pa. If the installer and MCS 'stuff' costs £500, then a lot of work for little gain.

5. Once again, you'll still need prior approval from the DNO for the 6kW inverter, or else you'll have an extra 3kWp of panels already installed on the roof, that you aren't allowed to connect up. Or you'd have to cap the inverter to 3.68kW, but that would waste (prevent) an awful lot of generation.

All my own thoughts, could be a complete load of nonsense, but even if this is possible, is it worth it for £50pa - borderline?

Mart.

pvforme

Hi,
Thanks for all the input. So much to take in. I have another salesman coming round tomorrow so I shall voice my new found information and gauge their reaction. I like the idea of splitting the system 4:3. Anything that's in my pocket sounds good for me.

I am also planning on speaking to the other guy who's quoted me, again to gauge his reaction. Maybe see if it can be split 4:3 and all for the same price

I guess that if they can fit it all together as suggested but only register one part to start with they should be able to keep the costs down. Depends how much they want the work I suppose. I will drive a hard bargain

Thanks again, will let you know how I get on

Martyn1981

Hello pvforme, just had another thought, possibly the final nail in the coffin for this suggestion. The tariff rate is dropping by at least 3.5% on 1/7/13. It might be more, all depends on the level of domestic installs for the quarter Feb to Apr. So we should know soon.

Again, only guessing / thinking out loud, but the chances of you being able to complete and register both systems before the end of June has got to be slim. So the 3kWp extension would then suffer a further 3.5% drop.

I'm really interested to know how an idea like this could/would pan out, and would appreciate your feed back, but in reality it's probably not worth the bother, more of a pipe dream on a quiet Sunday morning.

In reality, it's probably only worth bothering with if the install is marginally over 4kWp, say 5kWp (4 + 1). I'm gonna stick my neck out and say that the installers won't want the hassle for less than £500.

But heh, if you don't ask, you don't get! Let us know what they say, or how loud they laugh at the idea - if they do laugh, just blame some wally on a forum for the idea!!!

Mart.

pvforme

Just an update,

Had another 2 "quotes" in. First one came in at £10k,he said he'd be happy to split the install 4:3. I did mention the size beforehand and he has spoken to the DNO(verbally, not in writing) who have said it shouldn't be a problem. He will install all the panels to start but only connect the first 4kw. Best part is he's willing to wait for payment on the 2nd set until he has the approval

2nd quote, bluntly sounded like he was reading off a well groomed script. Very slick until I asked questions on inverter type, "Aurora" sprang to mind(thankyou Martyn), he got very defensive mentioning fronius and sunnyboy. This one says it wouldn't be possible to split the install, that there wouldn't be enough time. Worse was to come, £12500. I couldn't get him out of the door quick enough:mad:
I have the very first fella coming back to look at quoting on the split idea. He has mentioned extra paperwork bla bla bla,more money etc. will just have to see how much.

I have to admit that before coming on here I didn't know an inverter from a panel. You could have said anything and I would have believed it. At least now I can give the installers a little run for their money and maybe thanks to you guys (and gals) get myself a cracking deal. Thanks

Martyn1981

pvforme wrote: »

Just an update,

2nd quote, bluntly sounded like he was reading off a well groomed script. Very slick until I asked questions on inverter type, "Aurora" sprang to mind(thankyou Martyn), he got very defensive mentioning fronius and sunnyboy.

Hiya, that's very interesting, and quite positive.

Couple of little things, the FIT rate from 1/7/13 has now been confirmed at 14.9p (and 13.5p for 4-10kWp).

Also, please don't think badly of the Fronius and Sunnyboy mentions. They are very well known brands (SMA Sunnyboys, possibly the most popular). I did find good 6kW inverters from them too (Fronius IG Plus 60V 1 6kW Inverter 1 Phase & SMA Sunny Mini-Central SMC6000A Inverter), but they didn't have multiple MPPT's. Instead they used multiple strings going into the same MPPT.

That's absolutely fine and not an issue ...... except ...... all strings would have to be perfectly balanced to prevent losses, and I couldn't for the life of me work out how to split 7kWp into 4+3kWp whilst balancing all strings (up to 6) with an identical number of panels. At that point I found the Aurora, which was a little cheaper, and could be split 4+3 using an MPPT each (almost like having two inverters in 1 box), so I mentioned that one.

Sorry for all this gibberish, but don't be afraid of any installers who like to use those big brand inverters, they are quality, and if you decide to just do one FIT registration of 7kWp, then all of the inverters will work fine, I'm sure.

Happy hunting.

Mart.

pvforme

Just an update,

My first 4kWp are up and running. 16 shiny new sharp 250w panels linked to a sunnyboy. the other 3kWp are ready for connection, we put them up at the same time(thanks for the idea Martyn). We are waiting for final DNO approval, we did get it verbally so took a chance of installing the panels. I've been promised the correct paperwork this week so should be up and running before the deadline.
We've had 2 separate inverters and meters to avoid any confusion, one set will be on 15.44p and the other at 13.99(hopefully)

Total eventually came to a little under £10k

I'm quite pleased so far, we got the first panels running about 2 weeks ago and have generated nearly 250kWh. Can't wait for the 2nd set to come online as my electric meter seems like its stuck:D.

Thanks for the advice

Martyn1981

Hiya PVFM - I'm staggered!

Thanks for the thanks, but in truth I just threw the semi-ridiculous idea out there, and then tried hard to backtrack a bit, when you showed 'too' much interest in it.

I take my hat off to you for managing to actually arrange all of this in the necessary timeframe. Just a week left to get that second application in. Didn't somebody (???) say your chances were slim - go for it!

And all for approx £1,400/kWp.

I'm smiling away, but half of it is shock. Well done again.

Mart.

Discodave

Is anyone looking to have Solar Panelling installed? Is it is still worth it with the reduced FIT rate?

Cardew

Discodave wrote: »

Is anyone looking to have Solar Panelling installed? Is it is still worth it with the reduced FIT rate?

There is some discussion on the economics of fitting solar PV with the latest FIT rates here:

https://forums.moneysavingexpert.com/discussion/3325628

From post #2040 onwards.

Despite the inevitable arguments, it is very clear that you must take a long term view of such an investment.