This is a response to a previous post that unfortunately disappeared.
You can do that. You will lose a little bit on the efficiency of the inverter because its best efficiency is around the rated power, however, any photovoltaic installation works around the rated power only for a small time during the year, i.e. in the spring and summer, on clear days, from about 11.00 to 15.00, during the in winter you will rarely ever reach even 40% of the rated power. Another question is how the Energy Plant will look at it, I do not know whether they count the power of the panels or the power of the inverter as the power of the photovoltaic installation.
In addition, with installations with a power of up to 10kW, when you throw electricity into the grid, you can receive 80% of the energy thrown back from the grid for free, i.e. you lose 20%, while with an installation with a power of over 10kW, you can collect it back from the grid for free only 70% of the energy thrown into the grid, so you lose 30% irretrievably. This applies to prosumers, I do not know how it is in business.
With a 20kW inverter, you will connect the panels in strings in series and then strings with each other in parallel to fit within the MPP voltage range of the inverter. So if, for example, the MPP voltage range of the inverter will be 400-800V, and your panels with a power of e.g. 300W will give a voltage of e.g. 40V, then you will connect e.g. 15 panels in series and on this string you will have about 600V, and then you will have the power 15 x 300W = 4.5kW, to enlarge such an installation you have to make a second identical string and connect it in parallel to the first one, or if you have an inverter with two MPPs, then you can connect a string with a different power to the second MPP, but still to have 20kW you will have to connect the strings in parallel.
Another option - You can, for example, make a 4kW installation with an inverter, e.g. 6kW, then enlarge the installation by adding panels to 6 or even 7kW (it may be slightly oversized), the next time you enlarge the installation, you will buy another inverter and ultimately you will have 3 inverters, but one inverter with 20kW is definitely cheaper than 3 6kW inverters, but in case of failure it is better to have 3 smaller inverters than one big one, because your production will only be reduced by 1/3 during a failure.
