How much does it cost the owners of the Rogers Centre (née SkyDome) to open and close the roof?

How much does it cost the owners of the Rogers Centre (née SkyDome) to open and close the roof? I assume it must take a lot of juice.—Rupert Singh, East York

The retractable roof of the Rogers Centre weighs more than 21 million pounds and would cover nearly eight acres if laid out on the ground. Its panels roll courtesy of 54 “bogeys”: motorized carts that trundle along on steel wheels, taking roughly 20 minutes to complete their run. The roof isn’t separately metered, but officials say it’s responsible for a tiny fraction of the stadium’s overall hydro bill, the bulk of which goes to climate control; pressed for an estimate, they (reluctantly) guessed it costs about a hundred bucks a pop. There are, of course, other expenses tied to the roof’s operation. A team of four specialist technicians is on-site (to inspect components and make sure the tracks are clear); they act as spotters during closing and opening. The team is headed by a full-time roof technician who directs the show from the control room, stepping in to “drive” the roof with a joystick if anything goes wrong with the computerized autopilot. In 2001, the roof got into a costly fender-bender with itself when one of its sections stalled. But on the whole, the dome’s roof—considered an expensive gamble when it was built—bears little blame for the stadium’s money pit status.