“Initially the ribbons were curved in gentle spirals around the center but as they spread, they straightened out. The outer tips of each ribbon were tied to the tips of its neighbors which forced the ribbons to turn and lay all flat facing the sun.”

Deployment of a solar array is easy when you assume a flexible super-strong material as in the novel, but it can also be done if you have rigid solar cells as shown here:

Origami Solar Array Prototype from JPLraw on Vimeo.