More Solar?

[Alan Bradshaw]

I have a 4kw solar panel system on my main roof which has paid for itself in about ten years. I am on a very good FIT for this system. I would like to add a second system to another roof on my house which would be used under the SEG tariff, and with battery storage. Both systems would be connected to the same supply. Is this possible or would I be better fitting a new inverter with increased capacity? Ths thing is, the 4kw system is the biggest allowed under the FIT rules hence my idea of a seperate system. I would have liked to add a battery to my current system but the supplier I have chosen has let me down (only waiting 18 months!)

 

[user 36398]

From what I can gather your system using FIT cannot be modified, otherwise you loose the FIT bit. So forget about doing anything to that system, and leave it generating your FIT. Last thing you want to do is loose that..

I was in the same boat, my existing solar was FIT based, this was when it was 50p per kWh, with RPI for 20 years. I think last time I looked due to RPI it was about 63p, so definitely not something I wanted to mess with.

The good news is the SEG part of your existing solar can be transferred and a smart meter used for calculating export, if your on an export tariff, eg. Octopus Flux etc, and you just keep the FIT with your existing solar install. You will find your FIT install has it's own meter that you send to your supplier.

Both systems would be connected to the same supply. better fitting a new inverter with increased capacity?

It has to be a new inverter, like I said you cannot touch your existing one, or you will loose FIT. Apart from that the solar installer should have sized the inverter to your PV's, so there is unlikely to be any spare capacity.

After installing a new inverter, new panels, & battery. Don't worry it all works together, and any export you make from your old & new panels will get added together etc. One area I'm not 100% sure on is the battery charging aspect of an inverter, it will of course charge from you new PV's, or if asked charge from the Grid, but if you have access solar from 2 PV array's if it can charge from both. IOW: it see's a negative load and charges battery. Not sure!! My old PV array is pretty small, only 3 panels so it's not obvious if that happens or not. It certainly helps reduce grid load, so batteries start charging faster with the old PV adding to our supply. Maybe someone else might be able to confirm the logic there..

 

[bladerunnerpv]

Hello Alan, a number of ppl on the forum have had similar questions, and found solutions IIRC, suggest you have a trawl through the threads, and I think you'll find the answer already here. W.r.t adding battery to existing system, suggest trying searching with retrofit as a keyword. Hope this helps.

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