(220 ILCS 5/9-241) (from Ch. 111 2/3, par. 9-241)
    Sec. 9-241. No public utility shall, as to rates or other charges, services, facilities or in other respect, make or grant any preference or advantage to any corporation or person or subject any corporation or person to any prejudice or disadvantage. No public utility shall establish or maintain any unreasonable difference as to rates or other charges, services, facilities, or in any other respect, either as between localities or as between classes of service.
    However, nothing in this Section shall be construed as limiting the authority of the Commission to permit the establishment of economic development rates as incentives to economic development either in enterprise zones as designated by the State of Illinois or in other areas of a utility's service area. Such rates should be available to existing businesses which demonstrate an increase to existing load as well as new businesses which create new load for a utility so as to create a more balanced utilization of generating capacity. The Commission shall ensure that such rates are established at a level which provides a net benefit to customers within a public utility's service area.
    Prior to October 1, 1989, no public utility providing electrical or gas service shall consider the use of solar or other nonconventional renewable sources of energy by a customer as a basis for establishing higher rates or charges for any service or commodity sold to such customer; nor shall a public utility subject any customer utilizing such energy source or sources to any other prejudice or disadvantage on account of such use. No public utility shall without the consent of the Commission, charge or receive any greater compensation in the aggregate for a lesser commodity, product, or service than for a greater commodity, product or service of like character.
    The Commission, in order to expedite the determination of rate questions, or to avoid unnecessary and unreasonable expense, or to avoid unjust or unreasonable discrimination between classes of customers, or, whenever in the judgment of the Commission public interest so requires, may, for rate making and accounting purposes, or either of them, consider one or more municipalities either with or without the adjacent or intervening rural territory as a regional unit where the same public utility serves such region under substantially similar conditions, and may within such region prescribe uniform rates for consumers or patrons of the same class.
    Any public utility, with the consent and approval of the Commission, may as a basis for the determination of the charges made by it classify its service according to the amount used, the time when used, the purpose for which used, and other relevant factors.
(Source: P.A. 91-357, eff. 7-29-99.)