Generating equipment installed after December 31, 1974, for the purpose of converting from oil or natural gas to coal or to wood, wood bark, wood residue, or to any other alternate energy source for manufacturing, and any cogenerating equipment installed since such date for use in manufacturing, are hereby declared to be a separate class of property and shall constitute a classification for local taxation separate from other classifications of tangible personal property. The governing body of any county, city or town may, by ordinance, exempt or partially exempt such property from local taxation, and such ordinance shall become effective on January 1 of the year following the year of adoption.
Va. Code § 58.1-3662