Solar Panels Old FIT with New Export Payments?

zaber86

Hi with the rising gas/electricity costs I was considering having some extra panels fitted to my house. I currently have a 3KW system on a south facing roof. However I have East/West facing roofs that could potentially have solar panels fitted. I understand that the rules have changed for solar pannles since I had mine fitted, but don't understand where I would stand. The max to qualify under the new rules is 5KW or under, but can I have my 3KW and 5KW? or can I only get another 2KW? How would my supplier know what was exported from my old solar panels, and what came from my new ones for the export tariff? Or would I not qualify at all because of my existing panels? Thanks.

Keep_pedalling

According to farmers weekly you have to be careful in making changes to the system, as in increase in capacity could endanger your current FIT payments.

https://www.fwi.co.uk/business/diversification/farm-energy/how-to-avoid-jeopardising-fit-payments-with-solar-repairs

Petriix

I'm not sure about the overall limits (didn't think there was anything other than what the DNO restrict your property to).

I believe that the FIT payments would remain the same as long as you don't change anything connected to your generation meter, otherwise it gets a pro-rata reduction based on the increased in size.

You can opt out of the export part of the FIT payments and sign up for SEG payments instead, as long as you have a SMETS2 meter which can record exports.

QrizB

zaber86 said:

Hi with the rising gas/electricity costs I was considering having some extra panels fitted to my house. I currently have a 3KW system on a south facing roof. However I have East/West facing roofs that could potentially have solar panels fitted. I understand that the rules have changed for solar pannles since I had mine fitted, but don't understand where I would stand. The max to qualify under the new rules is 5KW or under, but can I have my 3KW and 5KW? or can I only get another 2KW? How would my supplier know what was exported from my old solar panels, and what came from my new ones for the export tariff? Or would I not qualify at all because of my existing panels? Thanks.

Your MCS installer will go through the details with you but in broad terms:

• If you install a second system with its own inverter, generation meter etc. it shouldn't affect your existing FITs.
• If you add additional panels to your existing system your FIT payments will be pro-rata'd. In your example if you have a 3kW system and add 2kW of new panels, you'll be paid for 3/5ths of your generation.

The first bullet option is probably the simplest to administer, and will probably me the most Moneysaving if the new panels are on a sub-optimal pitch of your roof (E/W not S-facing).

Independently of all that, on your current system you are probably on deemed export. If you have a smart meter you have the option of switching to metered export. Your new system will need an export meter so, depending exactly how it is installed, you might find you lose the deemed export on your current system too.

[Deleted User]

To revert to the original question. You can put as much PV Solar on your roof as you want; however,….. DNO notification only is required post installation when the inverter (and thus export) is limited to 3.86kWs on a single phase supply. This is why the original FIT scheme was limited to 4kWp arrays. If you want to add panels which have the potential of exporting - in total - more than 3.86kWs to the Grid then prior approval from your DNO has to sought for the proposed installation. The issue for the DNO is whether or not the Grid can cope with the level of export from your total system. 

The DNO will examine the proposed installation; it will review the local Grid infrastructure, and it will give you a total export limit for all your installations. The DNO will expect the installer to configure the inverter/s such that the total export limit is never exceeded. This doesn’t stop you putting an additional 5kWp’s worth of panels on your roof but you could be inverter limited. If you are contemplating getting a battery of any size, this is treated by DNOs as a potential generator and in all cases DNO approval is required. DNOs charge for all work done and they may insist on a post installation witness testing visit.

To put this into perspective. I have a 7kWp array and a PW2. As my array is orientated in 2 directions 90 degrees apart, my inverter is limited to 5kWs. Potentially, my PW2 can discharge to the Grid at 5kWs. My DNO has looked at my system and it has not imposed an export limit. Others have not been so lucky.

SEG payments. A lot of people who install additional PV elect to forego the export payments associated with the FIT  Scheme. They then total together all the exports and have them paid to them via SEG. To get SEG, a supplier such as Octopus will need you to have a smart meter; a MCS-approved installation, and it will require you to provide them with the DNO sign off for your system. The supplier will then apply to your local DNO for an export MPAN for your meter. Once this has been set up, the supplier will pay you SEG based on export readings from the meter. You will still be paid FITS for your original PV system.

PS. You also need to look carefully at the VAT rules for solar and battery installations. If you play the game, you can get away with 5 rather than 20% VAT.

jimjames

zaber86 said:

How would my supplier know what was exported from my old solar panels, and what came from my new ones for the export tariff? Or would I not qualify at all because of my existing panels? Thanks.

I looked into getting more panels when our house was extended and decided it wouldnt be worth it unless the installation was completely separate as we're on the original 2011 FIT tariff. If you make any changes to the installation then the additional capacity will be pro-rata and will reduce your existing FIT payments. The way to prevent that is to have a separate inverter and meter.