What is a NIETC?
A 'National Interest Electric Transmission Corridor', as assigned by the Secretary of Energy, is ''any geographic area experiencing electric energy transmission capacity constraints or congestion that adversely affects consumers."
The Secretary of Energy can designate an NIETC after considering:

"(A) the economic vitality and development of the corridor, or the end markets served by the corridor, may be constrained by lack of adequate or reasonably priced electricity;
(B)(i) The economic growth in the corridor, or the end markets served by the corridor, may be jeopardized by reliance on limited sources of energy; and (ii) A diversification of supply is warranted;
(C) The energy independence of the United States would be served by the designation;
(D) The designation would be in the interest of national energy policy; and
(E) The designation would enhance national defense and homeland security"

Definition: page 5661 of the February 2, 2006 Federal Register