A measurement of how much electricity it uses is not speculation. Don't go too far in your skepticism.

Edit: Unless someone has a specific reason I'm wrong, I stand by this. A criticism that makes four good points and one bad point is worse than a criticism that just makes four good points. I don't see any reason to call out the electricity use specifically as "pure speculation". It's only part of the cost but it's not a made-up number, and it's not a number that should change significantly between the lab and the real world.