Don't forget hydro-power. In my area, the word "hydro" is synonymous to "electricity" (in the sense of the utility, ie "hyrdo bill").
Is it because of the massive amount of concrete needed or because of something else?
One more question, by fuels used to cool the concrete, I'm thinking you are referring to powering the pumps that circulate the cool water in the tubes inside the concrete slabs, right? Or is it cooled differently?