IMHO - your friend could fit a 6kWp inverter with an export limiting device set at 3.68 kWp (16A) - will cost probably £300 but will solve his issue.
Don't forget that prior to installing an EV charger or a battery storage system, they will also need DNO (District Network Operator) approval beforehand especially battery storage as its classed as a generator same as PV. So if your fitting a >3.68kWp inverter and a battery storage system and an EV charger then you need 3 sets of approval.
Regarding the Solar generation getting back to grid, true in the sense it probably doesn't get back to the 400kv transmission network but it does get back to the local 11/33kv network that powers all the substations etc.
Now nearly all of my larger UKPN systems are export limited to 200 kWp - which means fit as much as you want (say 400 kWp) but your only ever allowed to export 200 kWp to the grid. (may only occur on a sunny Sunday in July when factory is shut so low consumption=high export).
Basically the grid local infrastructure can't deal with all the possible embedded generation applications that might be submitted so they are already starting to restrain the network.
Last edited by Stevo666; 20/09/22 09:09 PM. Reason: grammar
