Tenn. Code Ann. § 65-26-102

The corporation is authorized to charge a reasonable price for gas, not higher than the price allowed by existing charters to gas companies heretofore chartered in this state; provided, that the corporation shall never charge more than one cent (1¢) per every cubic foot of gas used, as may be indicated by the gas meter or computed by the ordinary rules in such cases; nor shall it at any time charge the authorities of the town, city, or village more per cubic foot than it is charging the inhabitants of such town, city or village at that time.