National Geographic: Tourists typically come to Ontario to gaze at the majesty of Niagara Falls or to breathe the fresh air of the boreal forest of the Northwest, not to bask in the sun. But Canadian sunshine grows grass tall enough to feed Bryan Gilvesey’s cattle, Texas Longhorns that he raises on a ranch he’s converting entirely to alternative energy. “It struck me that we’re really harvesting energy from the sun on these prairies,” Gilvesey says. “It seems that solar’s a natural for us …