Adding more panels - FIT implications

michaels

We have 4kw of panels facing 16 degrees S of W with a standard DNO compliant invertor (is this capped at 3.6kw or 4kw?) fitted 2 years ago.

Seems to me that we could add additional panels on our just N of W roof for not much more than the cost of the panels, fixings and scaffolding and put the output through the same invertor and only lose a small amount of generation at midday when both sets of panels are generating a lot.

Problem though would be that obviously all generation would be going through the FIT export meter which no doubt would break the rules. So even though the install would pay for itself based on the current much lower FIT rates because of not having to shell out for another invertor I don't suppose we would be able to be paid based on an estimated split of the generation between the old and new FIT rates.

Martyn1981

Extensions can no longer apply for FiT, so you wouldn't get any FiT nor export payments.

You could run it through the existing inverter, but as you say that would then go through the TGM. This isn't a problem legally as your FiT provider will simply apportion generation, but you lose out as the apportioning won't take account of the PV orientation, just the size.

So if you add 2kWp to the WNW roof, then your FiT provider will apportion 2/3rds to the old system and 1/3 to the new system, even if the new system generates a lower kWh/kWp.

See section 10 of the PV FAQs.

michaels

So no export payment as well as no FIT - so basically the economics would need to stack up on a use it or lose it basis - and in fact slightly worse than this because of the apportionment....I think I would need very cheap storage for it to make sense at all.

theboylard

Or run it on a seperate inverter - leaving the original install intact with it's corresponding FiT.
Yes it may cost more, but protects your original investment.

You could buy the inverter off ebay?
I bought my SolarEdge and optimisers (46! and the SE Key), both together less than £500
I've still got my Schuco branded SMA SunnyBoy 3300 in the garage, only 8 months use - thats available if anyone wants it.

Hardest part will be finding a MCS reg company to install - negotiate daywork maybe?

Dave_Fowler

If you are not applying for FIT registration, would you still need an MCS accredited installer - or just a standard qualified electrician?

Dave F