No reason it can’t be done on 120v (from a technical level). In fact, most solar inverters in the US could do this at a technical level as they basically do the same thing, just on a larger scale (higher current and therefore are wired in to electrical panels rather than through outlet as outlets have lower current limits). All you need is the inverter to synchronize its AC output to match grid. If you had a smaller inverter, you could just connect it to an outlet (ignoring building codes, insurance, and other non technical reasons). So the choice is then to have centralized larger inverters or smaller inverters per panel or 2. If you live in a very densely populated area where you can only pit a panel or 2 on a balcony or you don’t have control of your electrical panel, then the small inverter method makes sense.
No reason it can’t be done on 120v (from a technical level). In fact, most solar inverters in the US could do this at a technical level as they basically do the same thing, just on a larger scale (higher current and therefore are wired in to electrical panels rather than through outlet as outlets have lower current limits). All you need is the inverter to synchronize its AC output to match grid. If you had a smaller inverter, you could just connect it to an outlet (ignoring building codes, insurance, and other non technical reasons). So the choice is then to have centralized larger inverters or smaller inverters per panel or 2. If you live in a very densely populated area where you can only pit a panel or 2 on a balcony or you don’t have control of your electrical panel, then the small inverter method makes sense.