He's answering a different question than the one you asked. The one you asked was about power costs and the system's overall efficiency. He's describing something quite different, the inherent and inevitable waste that's in the generation cycle. It's one of those apples and oranges things, communication failure. We're talking about different things, it's all unintentional and well meant but it's common, a typical, a regular thing. Questions and answers that fail to produce clarity and understanding and so away we go again, in the wrong direction.
What we wanted was a moon rocket and we got a Mars probe with an instamatic camera. We needed a time machine but we just ended up with a device that allowed me to explore parallel universes while cleaning the toilet. Then there was the great alchemy failure, we tried to make gold and ended up with platinum – edible platinum. We built a tower, taller and grander and housing all the collected artworks, knowledge and wisdom of the world. We were locked out when we lost the key. We tried to synthesise artificial intelligence and then found God. Then God, perversely but predictably confounded us all by denying his own existence. Who could argue? Science, theology and convoluted conversation, chat and mindless goals, tyranny and mutation.