Besides looking dumb for your neighbors, how realistic would it be to pay for the racking and electrical to be installed, then add panels as one can afford? Adding panels is just bolt them into the rack and plug in the panel. It's as easy plug and play as it gets. If you set up the racking and electrical to fit the total planned panels, having less shouldn't be a problem. I assume that the city wouldn't let this fly as they'd want to inspect the final product. Never mind.