The 20-45VDC input range is compatible with two types of solar panels: 60-cell panels (Vmp: 26-30V, Voc: 34-38V) and 72-cell panels (Vmp: 35-39V, Voc: 42-46V). These panels should provide a minimum of 200W and can support up to a maximum of 1100W of power. For example, if you have 4pcs 250\ 30V (60 cells) solar panel,you can make 4pcs in parallel to connect the inverter.Or you have 3pcs 300\ 36V'v(72 cels) solar panel, you akso can make them inparalel to connect the inverter.