To my understanding regulation explains most of the difference. And it will vary a lot from place to place -- your experience will depend largely on local government policy and what your grid provider requires in order to establish the connection. E.g. locally I'm kinda forced to go with one of the power company's blessed installers. Cha-ching! If I understand Australian regulations, they tend to be more uniform nationally, there is less bureaucracy to drive up costs.
To my understanding regulation explains most of the difference. And it will vary a lot from place to place -- your experience will depend largely on local government policy and what your grid provider requires in order to establish the connection. E.g. locally I'm kinda forced to go with one of the power company's blessed installers. Cha-ching! If I understand Australian regulations, they tend to be more uniform nationally, there is less bureaucracy to drive up costs.