(a) The Commission may establish a system of accounts to be kept by the public utilities under its jurisdiction, or may classify said public utilities and establish a system of accounts for each class, and prescribe the manner of keeping such accounts.
(b) The Commission may require any public utility under its jurisdiction to keep separate or allocate the revenue from and the cost of doing interstate and intrastate business in North Carolina.
(c) The Commission may ascertain, determine, and prescribe what are proper and adequate charges for depreciation of the several classes of property for each public utility. The Commission may prescribe such changes in such charges for depreciation as it finds necessary.