Argh.
Your major problem is treating every natural system as though it were a closed unit that neither accepts energy from the environment or releases it. Once you realize it's all about flow, and not about filling or emptying a bucket, your calculations fall apart.
So what if a cooling tower evaporates 13 billion gallons per year into the atmosphere? Where do you think that vapor goes, never mind the heat?
Do you know that the NATURAL evaporation loss from Lake Ontario would amount to almost three feet of depth a year if the water wasn't being replenished?