Quote (my emphasis):
"In a leeward turn, aerodynamic forces combined with a large angle of bank and a large angle of drift provide a propulsive force enabling acquisition of ground momentum and ground kinetic energy without gaining airspeed or losing potential energy. During the climbing part of the wing-over, extra potential energy is gained due to the propulsive force."
What "propulsive force"? I may be missing something (don't answer that!) but, on the face of it, that is gobbledygook. Pity, because the sight of an albatross sustaining flight - mainly in ground-effect - with no apparent form of propulsion is awe-inspiring.
Cannot see how - assuming the wind is horizontal and constant at any given height above the sea - energy can be harvested to maintain flight-sustaining airspeed simply by manoeuvring. Sounds like "perpetual-motion" to me.