I know Bozon, I was just making fun of the phrasing: you just can't 'release' void.
I also think that the inventor is a bit optimistic about the energy balance. However, this design could very well work with very little external energy needed. Solar panels could be enough to fill the gap.
When I was a teen, I imagined for a sci-fi RPG adventure a vehicle based upon a shaped force-field: with air sucked out of the field it would rise, then the force-field would take the form of a wing and it would glide.