If you want to make use of a 400W panel with a system initially intended with smaller panels, Check out how to reconfigure for what you have already got… “They are not insurmountable difficulties,” said Michelle Davis, head of global solar for the energy research and consulting firm Wooden Mackenzie https://californiasolarservices.politics.blog/2024/02/15/4-ways-to-find-the-best-solar-installers-manteca/