For example, renewable technologies exploit the windiest or sunniest locations first, and, as they expand, they move into less and less productive territory. Losses of energy during conversion, storage and transmission will severely shrink the net energy available to society.
If we filled out the empty, flat spots in NM, we could generate much more than we use. Storage/transmission is the nut to crack. I need to read the papers they quote, though ... so my opinion balances on a fine grain of salt.