Why do you think it would need more power than e.g. your phone? Looks like it's "screens" are way smaller, so could/should consume less battery... If you limit

Why do you think it would need more power than e.g. your phone? Looks like it's "screens" are way smaller, so could/should consume less battery... If you limit the camera and "reality-processing" and just project the screen at a fixed distance in front of your eyes, it should be way more efficient than a phone.