Section 6(1)(a) in The Bihar Electricity Supply Undertakings (Acquisition) Act, 1979
(a)the cost incurred by the licensee for the assets including the cost of equipment or materials, cost of delivery, labour and other incidental charges properly incurred in erecting and bringing the assets into beneficial use as certified by the Special Officer appointed by the State Government or the Board as the case may be under Section 10, the book value of the fixed assets of the licensee put into beneficial use on or before 31st March, 1958, as shown in the books of the undertaking shall be taken as the book value of the fixed assets of the licensee up to that date ;the cost of fixed assets of the licensee put into beneficial use or in the process of being put into beneficial use during the period commencing from the 1st April, 1958 upto the date of vesting, shall be determined on the basis of the cost of similar assets incurred by the Board during each corresponding financial year of the cost of the fixed assets brought into beneficial use as shown in the books of the undertaking, whichever is less ;