Nuclear power, according to Brian Lumley. The 'blind idiot god' at the 'centre of creation' was, in Lumley's Mythos books starring Titus Crow, a symbol for 'the awesome power of the atom'.
An inclarity that I never quite managed to settle in my mind - during the first of his Titus Crow novels, 'The Burrowers Beneath', Lumley has his heroes using controlled nuclear explosions to destroy the Bad Guys, in this case vaguely Cthuloid spawn of Shudde-M'ell; and yet later reveals Azathoth, still a powerful symbol in the CCD mythology, to be, well, nuclear power. Logically, they should thrive on the stuff and reappear as Super-Evil Radioactive Beasties (tm)?
Don't be silly. It's Cthulhu. Logic doesn't come into it.