An energy conversion device is adapted to be housed within a unitized curtain wall unit as part of an exterior shell or fa\xe7ade of a building structure. The method includes selecting a sectional path option for a specific section selected by a user from an entire section between a start point and an end point, and finding a path in the specific section according to the sectional path option and creating an entire path for an entire section by employing the path in the specific section. The retention system may also have a replaceable lug insert removably disposed within the tapered depression. An adjusting unit adjusts the line voltage value and the line current value so as to satisfy the predetermined standard based on one of the voltage-current characteristic curves stored in the memory unit.