[Sudanpan]

We are thinking of a PV array. We had a site visit from the PV installers and the guy who came was very helpful and professional. We are going to have an east/west split array on our barn. We did look at ground mounted but you need planning permission for anything above 9sqm which is only about 5 panels....!
To cut a long story short we are going to go for a 6kw array, but the inverter is being capped at the 3.68kw level. We asked the surveyor why, if the inverter is capped at 3.68kw, can't we qualify for the higher FIT (currently 14.9p) but have to have the lower 13.5p FIT? He says it is because the actual 'installed' capacity is over 4 kw, even though the inverter is capped at the lower level.
Anyone know why this is so?
On a side note - it still works out at a better yield with the 6kw array on the lower tariff because the array allows for a better generation curve.

[Factotum]

It's the rules - and the tariff is based on installed capacity - if you fit enough panels for 6kWp, then you'll get the lower tariff - the inverter output is irrelevant when considering the tariff.

I understand that installations over 4kWp need to be checked by the local district network operator (up here that's Scottish Hydro) to make sure the current exported onto the network doesn't exceed 16amps. This adds to the cost of installation. Best check with your DNO to see what they say about over 4kWp installations.

Sue

[regen]

The reason it is being capped at 3.68 level is that 16 amps is the maximum thatcan be installed undera G83 which allows the installer to install and commision and then tell the DNO within a month. If it was not capped then G59 rules apply and the DNO may decide that anything more than 16 amps requires a major line or transformer upgrade. As stated your FIt payent is based on the TIC (total installed capicity )

Regen

[Sudanpan]

Thanks for that 


We are asking Western Power if they would need to upgrade anything if we did go for the uncapped inverter.


We shall see 

[cloddopper]

Thanks for that 


We are asking Western Power if they would need to upgrade anything if we did go for the uncapped inverter.


We shall see 

 That was the reason for us only having a 16 panel 4KwHr set up .

The power company can say we need to upgrade the local transformer so you can have the bigger FIT ... That will be £ 9 ,450 plus vat please etc etc sort of thing. It can also take an inordinate amount of time to get answers .

yet if you apply for the 4 kw hr set up and the transformer needs upgrading they have to bear the cost .

It was suggested to me rightly or wrongly to ask any electric board people who I might see working on the local transformer if they were upgrading the thing and if so then see about increasing my array .