Fonte: ANEEL
Stakeholders have until April 20 to contribute to the public hearing that calls into question the new parameters of internal restrictions in the transmission of submarkets to be considered in the formation of the Difference Settlement Price (PLD) of the energy sold in the short term. 

The current proposal seeks to consider the internal constraints operating in each submarket (such as the unavailability of transmission lines in a given period) for calculating the price of the short-term market. 

Thus, the LDP will reflect, more accurately, the operational reality of the National Interconnected System (SIN), approaching the Marginal Cost of Operation (CMO) *** calculated by the Independent System Operator (ONS) due to unexpected constraints for power transmission. 

The representation of these operating restrictions in submarkets in the PLD will increase operating efficiency and contribute to reducing the burden of System Services Charges (ESS )****, covering more expensive generation costs, thrown when there are restrictions on the operation planned. 

Public Hearing No. 013/2011, which began on March 17, will receive contributions until April 20 by e-mail: ap013_2011@aneel.gov.br, fax (55 61) 2192-8839 or by mail at the address SGAN – Quadra 603 – Módulo I – Térreo/Protocolo Geral da ANEEL – Brasília-DF – CEP 70830-030. 

The documents subject to public hearing are available at website www.aneel.gov.br , on the link Hearings/Consultations/Forum. (PG/DB/FA/CV/GL) 
* Submarkets: Divisions of the National Interconnected System (SIN) for which prices are set for specific Difference Settlement Prices (PLD) and whose borders are defined by the presence and duration of transmission of relevant restrictions on the electricity flow in the SIN. Currently, Brazil has 4 submarkets organized by geoelectric regions: North, Northeast, South and Southeast/Midwest.
ANEEL Resolution No.109, October 26, 2004 (Official Journal, October 29, 2004, section 1, p. 196) 

** Differences Settlement Price – PLD 
Price to be released by the Energy Trading Chamber (CCEE), calculated in advance with maximum weekly intervals based on the marginal cost of operation. It is bounded by minimum and maximum prices which apply to each Calculation Period and each Submarket, which is valued by the electricity sold in the Short Term. Currently, the Energy Trading Chamber (CCEE) does not consider internal constraints (such as falls of transmission lines) in this calculation.

*** Marginal Cost of Operation 
Cost per unit of energy produced to meet an increased load on the system. 
ANEEL Resolution No 109, October 26, 2004 (Official Journal, October 29, 2004, section 1, p. 196) ANEEL Resolution No 109, October 26, 2004 (Official Journal, October 29, 2004, section 1, p. 196) 

**** System Services Charges – ESS 
Monetary values ​​used to cover the cost of system services, including ancillary services, provided to users of the National Interconnected System – SIN, which include the costs of generation dispatched regardless of merit, for transmission constraints within each submarket, the operational reserve of power, in megawatts, provided by generators to regulate the frequency of the system and its ability of autonomous start, the spare capacity in MVAr, provided by generators, higher than the reference values ​​established for each generator in Network Procedures, required for operation of the transmission system, the operation of generators as synchronous compensators, voltage regulation and generation cut schemes and cargo charge. 
ANEEL Resolution No 109, October 26, 2004 (Official Gazette of 29 October 2004, section 1, p. 196)