In Arizona the valuation of electric generation facilities is governed by A.R.S. 42-14156(A) (Supp. 2007), which provides as follows: 2. the valuation of real property improvements used in operating the facility is the cost multiplied by valuation factors prescribed by tables adopted by the department. 3. the valuation of personal property used in operating the facility is the cost multiplied by the valuation factors as prescribed by tables adopted by the department, adjusted as follows: (a) for the first year of assessment, the department shall use thirty-five per cent of the scheduled depreciated value. (b) for the second year of assessment, the department shall use fifty-one per cent of the scheduled depreciated value. (c) for the third year of assessment, the department shall use sixty-seven per cent of the scheduled depreciated value. (d) for the fourth year of assessment, the department shall use eighty-three per cent of the scheduled depreciated value. (e) for the fifth and subsequent years of assessment, the department shall use the scheduled depreciated value as prescribed in the department's guidelines. 4. In addition to the computation prescribed in paragraphs 2 and 3 of this subsection, the taxpayer may submit documentation showing the need for, and the department shall consider, an additional adjustment to recognize obsolescence using standard appraisal methods and techniques.