SOR Payments. The Service Provider will receive a payment for each MW of SOR Available Volume it provides from the Providing Unit in each Trading Period determined in accordance with the following provisions of this Section 4.2. Unless stated otherwise, all parameters used in the calculation of such payments are the Time Weighted Average for a Trading Period. The payment to the Service Provider for SOR Available Volume of the Providing Unit in a Trading Period is determined as: SOR Trading Period Payment = SOR Available Volume SOR Payment Rate SOR Scaling Factor Trading Period Duration Where: