What you post is not your work unless you happen to be the original author. Someone may TOU your post for copyright so here is the reference you should have used,
Just two comments on what is a well prepared but flawed analysis.
1. Most of the energy in a coal fired boiler may get captured as steam but the process of turning hot gas into electricity is limited by the efficiency of the Carnot Cycle.
2. If the author is correct with his 50,000MW peak demand then baseload demand will be substantially less. 20 modern nuclear reactors operating at 7 or 8 sites would be able to supply much of that need. This would leave room for renewables to fill the gap.