Due to economy of scale, several methodologies for the allocation of power transmission costs do not recover the fixed costs of transmission assets. To avoid this problem, in this paper a methodology is proposed which considers that each circuit has two functions: to allow the power transmission between two points and to assure the system reliability. Thus, the revenue of each circuit is obtained in two parts: one part that considers the system use under normal state and the second part that consider the system use under contingency conditions. Application of the methodology is illustrated on a small, but realistic test system.
