existing FIT and new panels

bigrw

Hi All, I'm with Scottish Power Dual fuel. By chance, in 2012 the previous owners of our house had panels fitted on a good FIT (I think 45p?) which has transferred to us. All has worked fine. I have done an extension and would like to add 12-16 panels and a 9.5KwH battery. Ideally I'd like to run them as separate systems and keep my FIT, store my newly generated energy and sell any extra through SEG. In an even more ideal world, I'd like to be able to have a tariff to charge up my battery cheaply over night during the winter if needed. 

Any advice please? Is it even possible to have two electricity suppliers? Can Scottish power add another SEG without affecting my FIT?

be really grateful for advice.

thanks!

theboylard

I installed our panels in 2014, and have just added batteries to the mix, with the option to add panles in the future.

From my limited knowledge, you'll likely need a second inverter connected on the AC side - run the batteris and new panels off that.

I've got 15.6kwh of fogstar batteries connected to a Sunsynk 5kw hybrid inverter.

This meets the needs of the house over the day easily.

The solar covers the house needs and can charge the batteries easily on a brighter morning.

Can decide whether to charge to batteries from solar or not, and whether to export from the batteries or not.

I have the power!

I'm with Octopus Agile for house leccy and Tracker for gas, the Fit is with Good Energy.

I'm playing with the option to split off the export under the old Fit and go to fixed export on Octopus, but still keeping the Fit generation.

This is doable, and is the way to go if you are adding more panels?

Do you have an EV? That will make a difference regarding the overnight charging, but otherwise Agile is good for this, or if you wanted guaranteed night pricing then may be Octopus Flux or Go?

bigrw

Do you mean you have two providers of electricity or one provider and kept the FIT separate? Do you sell through SEG on your new system? 

Reed_Richards

The FIT comprises a payment for generation and a payment for export.  In 2012 it was difficult to measure export so by default you were deemed to export half of what you generated.  But if you have a smart meter that can measure export you can opt to be paid for actual export (or you might possibly be obliged to switch to being paid for actual export).  If you first do that then I think it should be possible to be paid for all the electricity you export, from both the old and the new panels.  You would also need DNO permission for whatever your maximum export might be.

bigrw

Sorry this is the bit I don’t understand. Can I keep me old FIT completely untouched. Not change contracts or anything. Then generate everything new through a new SEG deal. I’ve read all the forums etc and can’t seem to get my head round it! 

pete-20-11

No, you have to choose an export tariff, either FIT export or SEG export. 

And you can't get paid FIT export for the new panels. Nor FIT generation. If they accept the changes to the property, they'd pro-rate the generation (e.g. if you double the capacity in kWp they'll pay you for half of what you generate). 

bigrw

Understood. But I’ve read some comments saying you can have two completely unlinked systems. ie effectively you measure what you produce with your original panels and get your FIT and then measure you new ones and get SEG? websites all seem to contradict each other. Where do I find an expert? 

Reed_Richards

@bigrw, we keep telling you and you are not following.  You should get statements for your FIT payments, have a look at one and see what it says!

You cannot keep your FIT completely untouched, even with two completely unlinked systems.  Both systems will export electricity and there is no way of telling which system exports what electricity.  So you have to move to a regime where the way you get paid for the electricity exported from your old system is different to the way it is now.  That will change your FIT payments but you should still be able to receive the generous part of the FIT payment given for your generation.  

Also if the total power you can export at any instant exceeds 3.68 kW you need permission from your DNO and this might be refused or they might impose a cap.

bigrw

Sorry, I know I'm being dumb. Is it possible to have my new system not connected to the grid, so that I just generate and use from that and keep my FIT and meter totally untouched? i.e. I just charge and decharge my batteries internally only?

Reed_Richards

I don't think that is possible and It's a silly idea because you will keep the vast majority of the existing FIT payment and get paid extra for export. 

Follow my advice and actually look at a statement for your FIT payment.  You will see that it is made up of two parts, a payment for generation, which is very generous, and a payment for export, which is meagre by comparison.  If you follow the correct procedure you will get keep the generous generation payment and get paid (differently) for all the electricity you export from both your old and new systems.  Win win.      

Heedtheadvice

Apart from DNO approval aspects, can anyone tell this thread  why you cannot have an addition of a totally independent second panel generation system ( with batteries or not ) provided:

 you do not change the FIT generation system, FIT contract still stands and,

do not have SEG on the new system?

That way FIT is not altered technically or deemed export is still valid as it is not measured and,

No need to measure ' incorrectly' export for SEG then but that would preclude any SEG linked tarrif

Further the additional system can work as an off grid system. That would have a problem whenever there is not sufficient generation ( winter etc) to keep the batteries from going ' flat' and thus losing  power to whatever they supply. Possibly overcome technically by a changeover switch. Even a high number of panels as suggested by the OP would have a problem at some time or other.

It would need to correctly have correct equipotential bonding between the grid and off grid systems unless all co ducti e surfaces are sufficiently spaced and meet the regs for a domestic property.

And for clarity electricity supply contract and FIT contract are separate and can be with different electricity organisations.

Would be good to know if there are any reasons those suggestions cannot be done ( you may know issues that I do not) and if so can edit this post so as not to give bad info!!