CFR > Title 18 - Conservation of Power and Water Resources > CHAPTER I—FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY > SUBCHAPTER U—REGULATIONS UNDER THE PUBLIC UTILITY HOLDING COMPANY ACT OF 2005, FEDERAL POWER ACT AND NATURAL GAS ACT (parts 366 to 369) > PART 367—UNIFORM SYSTEM OF ACCOUNTS FOR CENTRALIZED SERVICE COMPANIES SUBJECT TO THE PROVISIONS OF THE PUBLIC UTILITY HOLDING COMPANY ACT OF 2005, FEDERAL POWER ACT AND NATURAL GAS ACT > SUBPART B—General Instructions (§367.2 to §367.30) > 367.20—Depreciation accounting.

367.20—Depreciation accounting.

(a) Method. Service companies must use a method of depreciation that allocates in a systematic and rational manner the service value of depreciable property over the service life of the property.
(b) Service lives. Estimated useful service lives of depreciable property must be supported by objective evidence and analysis, including where appropriate engineering, economic, or other depreciation studies.
(c) Rate. Service companies must use percentage rates of depreciation that are based on a method of depreciation that allocates the service value of depreciable property over the service life of the property. Where composite depreciation rates are used, they must be based on the weighted average estimated useful service lives of the depreciable property comprising the composite group.