When the state finance committee issues revenue bonds as provided in RCW 43.21A.620, it shall, as a part of the plan and system, request the state treasurer to establish a special fund or funds to defray the cost of the steam electric utility, or additions or betterments thereto or extensions thereof. The state finance committee may obligate and bind the director to set aside and pay to the state treasurer for deposit into such fund or funds a fixed proportion of the gross revenue of the steam electric utility and all additions or betterments thereto or extensions thereof, or any fixed amount out of, and not exceeding the fixed proportion of such revenue, or a fixed amount without regard to any fixed proportion, or an amount of the revenue equal to a fixed percentage of the aggregate principal amount of revenue bonds at any time issued against the special fund or funds. It may issue and sell utility bonds payable as to both principal and interest only out of such fund or funds.

The revenue bonds shall be payable at such places and times, both as to principal and interest, and bear interest at such rates payable semiannually as the state finance committee shall determine.