W. Va. Code § 24-2-15

The commission shall not enforce, originate, continue, establish, change or otherwise authorize or permit an increase in the charge or charges for electric energy over and above the established and published tariff, rate, joint rate, charge, toll or schedule as the result of any automatic adjustment clause, fuel supply price index, or fuel adjustment clause. Automatic adjustment clauses, fuel supply contract price indexes, or fuel adjustment clauses that do not create a net increase in the charge or charges for electric energy over and above the established and published tariff, rate, joint rate, charge, toll, or schedule shall be permitted by the commission. For purposes of this section, a "net increase" in the charge or charges for electric service shall mean that for the calendar year in which the automatic adjustment clause, fuel supply contract price index, or fuel adjustment clause is utilized, the average charge or charges for electric energy are higher than they would have been if the adjustment clause, fuel supply contract price index, or fuel adjustment clause were not utilized. The commission shall encourage the use of permitted automatic adjustment clauses, fuel supply contract price indexes, or fuel adjustment clauses as a means of increasing the generation of coal-fired power plants within the state. The Commission shall promulgate procedural rules governing the utilization of automatic adjustment clauses, fuel supply contract price indexes, and fuel adjustment clauses.