I have a small suggestion:
Let steam turbines accept steam from other steam turbines that run with steam and not superheated steam. That way one could chain more steam turbines together and every added turbine would be less efficient than the one before, so it would be a self balancing system. The only thing to keep in mind is that there is no perpetual motion. So the electric heat generation must be less efficient than the energy generation from heat. If one would chain 10 Steam turbines the result would be ~ 7 Steam turbines running with full steam power.
One suggestion would be to change the excess steam to 50% that way the series would converge to 2 (1 + 1/2 + 1/4 + ... = 2)
EDIt: Of course other values can be chosen to balance towards a specific efficiency.
One could change the electrical heat generator to be as efficient as a setup with infinite Steam Turbines.