With 56% of the electricity on the U.S. grid produced by coal-fired generators, the Internet s share of fuel use is on the order of 70 
(the U.S. grid; produced; by coal-fired generators) (the Internet s share of fuel use; is; on the order of 70)
the U.S. grid the Internet s share of fuel use
produced is
by coal-fired generators
on the order of 70