I would be interested to know, although after talking to Ofgem and a lot of research, if you use non listed panels or any second hand equipment (second hand panels or inverter) then it automatically does not qualify. The installation has to be "completed" by an MCS certified entity and this could mean that they just sign it off as qualifying... metering has issues.
My installation is non qualifying because I used second hand panels, battery packs do not fit in the scheme at all if they are charged directly from solar with a MPPT charge controller because as I understand it all metering is AC based post inverter and no DC metering capacity at all which adds to the issues. Means you have to have a grid tie inverter and then a separate charge controller that can charge from the mains tracking the solar output or your total house demand. There are some that say the FIT meter goes after the inverter on your battery pack, but this then makes the limitation you have to have all of the power out via a MCS registered and qualifying battery inverter, of which there are few and very expensive....
For me the cost of going MCS and tariff route was over 3x what it cost me for the same capacity, the extra 2x the cost would not pay back from the FIT as I do not believe that the 50% deemed export will continue post 2022 or after the smart meter roll out is completed. If you have no exports (you battery pack and home use should see to that) then the FIT is only the generation value... post 2022. Could make sense but a generation only return for a FIT at current rates can make for a very, very long payback.
I would be really, really, really, really, happy if I could qualify but under the existing schemes I may see a formation of pigs flying overhead beforehand. Please let me know if you find out if there is a way...