I am aware of the 2nd law. I am looking for data on the magnitudes involved. Every time there is a promise of very cheap energy, I wonder how we will deal with the waste heat.
The waste heat will be radiated away to space. The premise of global warming is that CO2 (and other "greenhouse" gasses such as methane) cause more of the heat to be retained in the atmosphere.
The magnitude is the same as current power sources that they would be replacing i.e. 100's of MWs to 1-10s of GWs. The amount of heat being brought up would have to be about the same as you would otherwise be getting from coal, gas etc and so the same amount of heat would be vent to the environment.
