NERSA does not use the marginal cost based method for electricity tariffs but rather the revenue requirement method. The Electricity Regulation Act requires that NERSA allow an efficient operator to recover its cost plus a reasonable return. This method is applied fully for Eskom. In case of Municipalities, this method has just been approved for implementation. It has therefore not been applied for municipal regulation. The cost of supply studies will be performed by municipalities and submitted to NERSA for review and consideration when municipal tariff applications are considered.