Any member governmental unit of an authority may contract to buy from the authority power and energy required for its present or future requirements, including the capacity and output of one or more specified projects. Any such contract may provide that the governmental unit so contracting shall be obligated to make payments required by the contract whether or not a project is completed, operable or operating and notwithstanding the suspension, interruption, interference, reduction or curtailment of the output of a project or the power and energy contracted for, and that such payments under the contract shall not be subject to any reduction, whether by offset or otherwise, and shall not be conditioned upon the performance or nonperformance by the authority or any other member governmental unit under the contract or any other instrument. Such contracts with respect to any project may also provide, in the event of default by any member governmental unit which is a party to any such contract for such project in the performance of its obligations thereunder, for other member governmental units which are parties to any such contract for such project to succeed to the rights and interests and assume the obligations of the defaulting party, pro rata or otherwise as may be agreed upon in such contracts. Notwithstanding the provisions of any other law or local charter provision to the contrary, any such contracts with respect to the sale or purchase of capacity, output, power or energy from a project may extend for a period not exceeding fifty years from the date a project is estimated to be placed in normal continuous operation; the execution and effectiveness thereof shall not be subject to any authorizations or approvals by the Commonwealth or any agency, commission or instrumentality or political subdivision thereof except as specifically required and provided in this chapter. Payments by a governmental unit under any contract for the purchase of capacity and output from an authority shall be made solely from, and may be secured by a pledge of and lien upon, the revenues derived by such governmental unit from the ownership and operation of the electric system of such governmental unit, and such payments may be made as an operating expense of such electric system. No obligation under such contract shall constitute a legal or equitable pledge, charge, lien or encumbrance upon any property of the governmental unit or upon any of its income, receipts or revenues, except the revenues of its electric system, and neither the faith and credit nor the taxing power of the governmental unit are, or may be, pledged for the payment of any obligation under any such contract. A governmental unit shall be obligated to fix, charge and collect rents, rates, fees and charges for electric power and energy and other services, facilities and commodities sold, furnished or supplied through its electric system sufficient to provide revenues adequate to meet its obligations under any such contract and to pay any and all other amounts payable from or constituting a charge and lien upon such revenues, including amounts sufficient to pay the principal of and interest on bonds of such governmental unit heretofore or hereafter issued for purposes related to its electric system. Any pledge made by a governmental unit pursuant to this paragraph shall be governed by the laws of the Commonwealth. Any member governmental unit of an authority may furnish the authority with money and provide the authority with personnel, equipment and property, both real and personal. Any member governmental unit may also provide any services to an authority. Any member governmental unit may contract for, advance or contribute funds to an authority as may be agreed upon by the authority, and the member governmental unit and the authority shall repay such advances or contributions from proceeds of bonds, from operating revenues or from any other funds of the authority, together with interest thereon as may be agreed upon by the member governmental units and authority.