Like the original concept, the stormrider had rectangular....

“ Like the original concept, the stormrider had rectangular blades, sixteen of them radiating out from the hub, each one a flat lattice of struts twenty-five kilometers long, made from the toughest steelsilicon fibers the Commonwealth knew how to manufacture. Twenty-three kilometers of them were covered by an ultra-thin silvered foil, giving a total surface area of over one thousand eight hundred square kilometers for the solar wind to impact on. Even in an ordinary solar system environment that would have produced a considerable torque. In the Half Way system the stormrider was positioned at the Lagrange point between the red star and its neutron companion, right in the middle of the plasma current, where the ion density was orders of magnitude thicker than any normal solar wind. The power the stormrider produced when it was in the thick of the flow was enough to operate the wormhole generator. But it couldn’t simply sit at the Lagrange point producing electricity continuously; that would have been too much like perpetual motion. As the waves of plasma pushed against it, they exerted an unremitting pressure on the blades that blew the stormrider away from the Lagrange point out toward the neutron star. So for five hours the two sets of blades would turn in opposite directions, generating electricity for the Port Evergreen wormhole that was delivered via a zero-width wormhole. The stormrider also stored some of the power, so that at the end of the five hours when it was out of alignment, it had enough of a reserve to fire its onboard thrusters, moving itself even farther out of the main plasma stream where the pressure was reduced. From there it chased a simple fifteen-hour loop back around through open space to the Lagrange point, where the cycle would begin again. ”

Peter F. Hamilton

From : Judas Unchained