(1) The commission is authorized to approve rates on an experimental or transitional basis for any public utility to encourage energy conservation or to encourage efficiency. The application of such rates may be for limited geographic areas and for a limited period.
(2) The commission is authorized to approve the geographic area used in testing experimental rates and shall specify in the order setting those rates the area affected. The commission may extend the period designated for the test if it determines that further testing is necessary to fully evaluate the effectiveness of such experimental rates.