(1) Direct obligations of the United States government or any of its agencies;

(2) Obligations guaranteed as to principal and interest by the United States government or any of its agencies;

(3) Certificates of deposit and other evidences of deposit at state and federally chartered banks, savings and loan institutions, or savings banks deposited and collateralized as described in § 7-36-123;

(4) Repurchase agreements entered into with the United States or its agencies or with any bank, broker-dealer, or other such entity so long as the obligation of the obligated party is secured by a perfected pledge of full faith and credit obligations of the United States or its agencies;

(5) Guaranteed investment contracts or similar agreements providing for a specified rate of return over a specified time period with entities rated, at the time of investment, in one (1) of the two (2) highest rating categories of a nationally recognized rating agency;

(6) The local government investment pool created by title 9, chapter 4, part 7;

(7) Direct general obligations of a state of the United States, or a political subdivision or instrumentality thereof, having general taxing powers and rated, at the time of investment, in either of the two (2) highest rating categories by a nationally recognized rating agency of such obligations;

(8) Obligations of any state of the United States or a political subdivision or instrumentality thereof, secured solely by revenues received by, or on behalf of, the state or political subdivision or instrumentality thereof irrevocably pledged to the payment of the principal and interest on such obligations, rated, at the time of investment, in the two (2) highest rating categories by a nationally recognized rating agency of such obligations;

(9) The authority's own bonds or notes; or

(10) Any additional investments authorized to be made by a municipal electric system in this state.