Calculation of Net Charges/Benefits. The net energy metering calculation shall be made by measuring the difference between the electricity which the electric utility delivered to the eligible customer-generator and the sum of: (a) The electricity generated by the eligible customer-generator and fed back to the electric grid over a monthly billing period; and (b) Any unused credits for excess electricity from the eligible customergenerator carried over from previous months since the last 12-month reconciliation period. Source: PL 15-23, § 2(8636), modified; reenacted without change by PL 1587 § 2(8636).