The Monthly Calculation of Transmission Charges and Services - AMSE basically involves calculation of revenue to be paid to the transmission service providers (transmission utilities and ONS) and Charges for Use of Transmission System - EUST and the Sectors to be charged for each user of the Basic Grid and the Border Grid.

The process of AMSE considers all parameters needed for the calculations of revenue (Allowed Annual Revenue, Share of Adjustment of Previous Cycles, among others), charges (tariffs, contracted demands and generation) and as well as all the variables involved (Variable Share due to unavailability of facilities, Financial Additional due to Exceeding Demand, New Agents, ONS Modulated Budget, Revenue of New Works).

AMSE ended the year with 90 transmission utilities and 234 users, being 228 permanent and six temporary. The total of charges and revenue paid during the year amounted to R$ 11.622 billion.

The calculation of additional financial costs associated to the exceeding of contracted values by distribution agents was initiated in 2011, according to ANEEL Normative Resolution No. 399/2010, which improved the regulation of transmission contracts regulation. Another relevant fact in 2011 was the beginning of the calculation of transmission charges associated to off-peak tariffs for distribution agents and free consumers.