We have interesting results from Russia.
@s_grey is the user who makes these attempts, he will add more information soon,
He will also answers questions in this thread.
Well, that "excess" heat. Within about 40 minutes. gave extra power reactor, about .. (700-380) / 3 = 100W. And, little by little increased temperature (at a rate 1g / min - setting PID controller), and the power first increases, and then began to fall! On the chart you can see everything.