Within one panel, there are typically many cells in series (eg. a typical house might have 8 panels, each with 60 cells in series, giving an open circuit voltag

Within one panel, there are typically many cells in series (eg. a typical house might have 8 panels, each with 60 cells in series, giving an open circuit voltage of about 30 volts per panel). This discussion is about cells within the panel, not panels within the system. So far, nobody has designed inverters that can work on the 0.5 volt output of an individual cell - although I agree that if such a thing existed, it would indeed help to boost efficiency when cells are mismatched or panels are part shaded. The challenge with 0.5 volt inverters is that currents are large and voltages are small for a given amount of energy, meaning all the parts of the inverter need to be very low resistance, thick wires, and expensive (due to more copper).