- Pending the approval by RAEWW of the Methodology for determining revenue required by the HETS Operator for operation of the Markets in accordance with the provisions of Article 6.1, paragraph 1 of this Rulebook, as well as the accounting separation rules to which the HETS Operator is subject, in accordance with the provisions of Article 141 of Law 4001/2011, the approval of the Balancing Market Fee is based on the HETS Operator’s own estimates of Revenue Required for the operation of the Markets with the possibility of corrective settlement after adoption of the aforementioned decisions of the RAEWW.