22. Where energy is supplied by a licensee, every person within the area of supply shall, except in so far as is otherwise provided by the terms and conditions of the license, be entitled, on application, to a supply on the same terms as those on which any other person in the same area is entitled in similar circumstances to a corresponding supply: Provided that no person shall be entitled to demand, or to continue to receive, from a licensee a supply of energy for any premises having a separate supply unless he has agreed with the licensee to pay to him such minimum annual sum as will give him a reasonable return on the capital expenditure, and will cover other standing charges incurred by him in order to meet the possible maximum demand for those premises, the sum payable to be determined in case of difference or dispute by arbitration.