Thanks Bobster, I appreciate your input.
My monthly usage is 450kw/h, I was surprised to see that Phocos inverters were not included on the city's list, I wonder how often the city amends that list?
I don't plan to export anything back to the grid, but I will look at increasing the power of the system and adding another battery, any advice on which inverter is the quietest as I live in a terraced house and would like the system to be as quiet as possible?