A contract for installing, maintaining and servicing a system of lights in any maintenance district shall be awarded to the lowest responsible bidder. However, the rates to be paid shall not exceed the lawful rates applicable for the particular class of service and when necessary shall be those authorized by the Public Utilities Commission of the State of California. The contract for service shall be for a period not less than three years from and after the date electric energy and service is first delivered to the maintenance district pursuant to such contract and shall be extended automatically thereafter for successive terms of one year each; provided, that the agreement may be terminated by either party upon not less than 60 days’ written notice prior to the expiration date of the original term or any extended term. The board of supervisors shall reserve the right to abrogate the contract whenever service is offered to be supplied at two-thirds of the fixed contract price.