I am willing to do my own math but can someone steer me to a formula where I could convert BTUs or Watts into energy output in the form of temperature?

Example I have a 700 Megawatt power station, which I know heats up the water outflow (one form of heat escaping), but some factor of heat escapes into the atmosphere. Is there a way to mathmatically scale and capture this heat exchange? Does anyone know of studies done on this. I am doing the usual Yahoo Google searches but some of the membership here seems to have better connections to academic research.

Is this wrong thinking but can I convert 700 Megawatts into something like 355 degrees F or whatever C or Kelvins?