In order to encourage the construction of transmission facilities necessary to transmit electric power from generating facilities located in this state to areas where such power can be economically marketed, the commission may allow an electric utility accelerated rate recovery for transmission facilities constructed or upgraded for the purpose of increasing the capacity to transmit electric power to areas outside the utility's service territory where such power can be economically marketed. In allowing accelerated rate recovery, the commission shall include the impact of the investment in transmission facilities on any investment equalization agreement in which the utilities participate.