Section 4. Public utilities

The real property of public utilities is subject to real estate taxes imposed by local taxing authorities. Payment to the Commonwealth of gross receipts taxes or other special taxes in replacement of gross receipts taxes by a public utility and the distribution by the Commonwealth to the local taxing authorities of the amount as herein provided shall, however, be in lieu of local taxes upon its real property which is used or useful in furnishing its public utility service. The amount raised annually by such gross receipts or other special taxes shall not be less than the gross amount of real estate taxes which the local taxing authorities could have imposed upon such real property but for the exemption herein provided. This gross amount shall be determined in the manner provided by law. An amount equivalent to such real estate taxes shall be distributed annually among all local taxing authorities in the proportion which the total tax receipts of each local taxing authority bear to the total tax receipts of all local taxing authorities, or in such other equitable proportions as may be provided by law.

Notwithstanding the provisions of this section, any law which presently subjects real property of public utilities to local real estate taxation by local taxing authorities shall remain in full force and effect.